Tart Cherry Extract Standardization: A 73-Fold Spread in Polyphenols, and Little on the Label

The short answer. You can only check a tart cherry extract label if it states three things: a standardization percentage, the milligrams of total polyphenols per capsule, and the assay method behind that number. Extraction ratios such as 10:1 and whole-fruit equivalents such as “10,500 mg” describe a manufacturing step or a calculation, not the dose in the capsule. When researchers measured ten fruit polyphenol supplements in 2022, total phenolics varied 73-fold. Tart-C™ is a USDA Organic tart cherry extract standardized to ≥25% total polyphenols (≥50 mg per capsule) and assayed by the Folin-Ciocalteu method. It has not been studied in its own clinical trial.

In 2022, researchers at Sheffield Hallam University bought ten polyphenol-rich fruit supplements sold in the UK and measured what was in them. Total phenolics ranged from 13.8 to 1,007.3 mg gallic acid equivalents per serving. That’s a 73-fold spread across products a shopper would treat as broadly interchangeable (Rickards et al. 2022, Journal of the International Society of Sports Nutrition).

The labels disclosed little. Only one of the ten listed a total-phenol figure, and its measured content came in at under a tenth of that figure. Half listed anthocyanins, and for most of those the measured amount was 0.2 to 2% of the stated value. The authors called this limited compositional information. Their conclusion is the one that matters: a user would have to choose how much of a supplement to take according to its actual polyphenol content, and almost no label provides that information.

A few more things about that study, stated here rather than buried:

• Not all tart cherry. The ten products were six cherry (five concentrates and one capsule), two pomegranate, one blueberry and one New Zealand blackcurrant.
• A spread even within one fruit. Among the tart cherry concentrates alone, the range was 208 to 591 mg gallic acid equivalents per serving. That’s still a 2.8-fold difference between products a buyer would treat as the same thing.
• Funding. The study was funded by Sheffield Hallam University and Sheffield United Football Club.

That’s the real shape of the problem. It isn’t that the products are weak. It’s that you can’t know what’s in them. If you’ve been spending several hundred dollars a month on a regimen you can’t defend item by item, you weren’t being careless. You were working with the only information anyone gave you.

In our September 2026 review of US retail and Amazon listings, Tart-C™ was the only finished tart cherry supplement we found that is both USDA Organic certified and labeled with a total-polyphenol percentage and amount. (1)

What Does the Research on Tart Cherry Support? The Evidence at a Glance

Here’s the whole picture on one screen, before the detail. Trial-by-trial sample sizes and funding follow later on the page.

 

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Read together, the evidence points to a modest effect on CRP and favorable antioxidant markers in several small trials, with capsule results mixed. That’s the honest size of the evidence, and it’s why the two claims on this page are worded as support rather than outcomes.

Is 50 mg of Polyphenols a Low Dose?

It’s a smaller number than this category has trained buyers to expect. But the bigger numbers often aren’t measuring the same thing:

• Whole-fruit equivalents. A front-panel figure like “10,500 mg” is usually a whole-fruit equivalent: a calculation based on fruit that isn’t in the bottle.
• Extraction ratios. A ratio like 52:1 describes a manufacturing step, not a dose.
• Assayed content. Fifty milligrams is the measured polyphenol content of the capsule.

Here’s the comparison. Each Tart-C™ capsule provides ≥50 mg of total polyphenols. Two published capsule trials gave 500 mg/day of one tart cherry extract. That extract tested at 5 to 6% polyphenols in one trial, about 25 to 30 mg/day (Hooper et al. 2021), and at 3.2% in the other, about 16 mg/day (Jäger et al. 2026). That is dose arithmetic, not an outcome comparison. Taking more polyphenol than was studied isn’t known to produce an equal or greater effect. (2)

Notice what that spread itself tells you. The same extract tested at 5 to 6% polyphenols in one trial and 3.2% in another. That’s the case for testing every lot, made by the published research rather than by us.

One honest counterpoint belongs here, from the same 2022 study this page opens with. Its authors cite proposed thresholds of roughly 300 mg of polyphenols before exercise for performance, and over 1,000 mg per day for faster recovery from muscle damage. Those are exercise-performance thresholds, not thresholds for inflammatory or antioxidant markers, and this page doesn’t make an exercise-performance claim. But a page about disclosure shouldn’t quote a study selectively.

What Is Tart-C™? Certified Organic, With the Lab Result for Your Lot

≥25% total polyphenols. ≥50 mg per capsule. Folin-Ciocalteu, reported as gallic acid equivalents. A number you can’t check isn’t a specification.

Tart-C™ is a single-ingredient organic tart cherry extract made by Triquetra Health for buyers who read Certificates of Analysis:

• Extract: 200 mg of chromatographically purified, European-grown, certified-organic Prunus cerasus fruit extract per capsule.
• Standardization: ≥25% total polyphenols, delivering ≥50 mg per capsule.
• Assay: Folin-Ciocalteu, reported as gallic acid equivalents. The result is published and QR-linked for each lot.
• Capsule: organic pullulan.
• Other ingredients: organic tapioca flour and organic rice hulls.

Tart-C™ supports a balanced inflammatory response and promotes antioxidant protection against oxidative stress.*

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Tart-C™’s label carries additional structure/function statements that are outside the scope of this page. This page covers two in depth: a balanced inflammatory response and antioxidant protection. It sets out the human evidence for those two areas, including the trials that found nothing, and lists seven benefits we assessed and chose not to claim here.

Tart-C™ is USDA Organic certified by Oregon Tilth. You can look up the certificate in the USDA Organic Integrity Database.

One more disclosure belongs here, because it’s the kind of thing this audience finds on its own. The two capsule trials cited on this page used a different tart cherry extract. It was a commercially available, spray-dried 10:1 water extract of European tart cherry, stabilized with rosemary extract. It was analyzed by the same Folin-Ciocalteu method Tart-C™ uses, at lower polyphenol amounts than one Tart-C™ capsule.

Tart-C™, by contrast, is a chromatographically purified extract at ≥25%. The two materials aren’t chemically identical, and the mix of compound classes within them may differ, so results from that extract can’t be assumed to apply to Tart-C™. No anthocyanin figure is published, because none has been verified.

How Do You Check the Certificate of Analysis for Your Lot?

It takes about 30 seconds:

1.     Find the lot number printed on your bottle.

2.     Scan the QR code on the label, or enter the lot number at [COA-LOOKUP-URL].

3.     Check three lines on the certificate:

o   total polyphenols (≥25%)

o   the method (Folin-Ciocalteu, reported as gallic acid equivalents)

o   the test date

4.     Check the purity results on the same page: heavy metals and microbes.

If a number on the certificate doesn’t match the label, you’ll see it before we can explain it away. That’s the point.

What Should a Supplement Brand Disclose That Most Don’t?

Four things, and the absence of any one of them tells you something.

1.     The quantity of each active compound, not just the extract weight. A 500 mg extract standardized to 2% contains 10 mg of actives.

2.     The assay method behind any stated figure. Values differ substantially by method, and an undisclosed method makes a number impossible to compare with published research. A 2021 review of 43 tart cherry trials found that over half didn’t analyze the batch actually used. It recommended batch-specific testing, stability testing, and compound-specific methods such as HPLC alongside total-phenol assays like Folin-Ciocalteu (Sabou et al. 2021, Frontiers in Nutrition). Tart-C™ reports Folin-Ciocalteu results per lot. Compound-level HPLC profiling is still an open item, disclosed below.

3.     The sample size and funding source of every study cited. A favorable result from ten participants in an industry-funded trial is a different thing from a result in three hundred.

4.     The benefits that were assessed and deliberately not claimed. Almost nobody discloses this.

Tart-C™ publishes all four:

1. Actives: ≥25% total polyphenols, ≥50 mg per capsule.
2. Method: Folin-Ciocalteu as gallic acid equivalents, stated on every Certificate of Analysis.
3. Studies: sample sizes and funding sources every time a trial is cited, alongside the trials that found nothing.
4. Exclusions: a published list of the benefits assessed and not claimed on this page, which currently runs to seven.

Why Can’t You Compare Tart Cherry Supplement Labels?

You did it on a Sunday, probably. Took the bottles off the shelf, lined them up, worked through them one at a time. And somewhere around the fourth one it became clear the exercise couldn’t be finished. Not because the information was hard to find, but because it wasn’t there. One said 10:1. One gave a proprietary blend total. One printed a whole-fruit equivalent in a font size that suggested confidence.

That’s two to four hundred dollars a month on a regimen you can’t defend item by item. It’s a different problem from the one this category usually addresses. You aren’t unwell and you aren’t looking for relief. You’re optimizing, and optimizing requires information you’ve never been given.

So things came off the shelf. Some of them probably deserved to stay, and you’ll never know which. You cut them on the same missing information you’d bought them on.

You aren’t a niche:

• Transparency and purchase intent. In a multi-country survey of supplement users, 67% said transparency information on a label or website would make them more likely to buy (Trust Transparency Center).
• Grocery shoppers generally. In 2020, 81% of grocery shoppers rated transparency as important or extremely important when shopping in-store or online (FMI and Label Insight 2020). That figure covers grocery shoppers in general, not supplement buyers specifically.
• Brand choice. One in five US consumers make a transparent vitamin and supplement brand their first choice (Pure Branding).
• Traceability and FDA approval. In a 2024 Ipsos survey commissioned by Amway (n=1,000 US adults aged 18 to 70), two in three respondents said they were more inclined to buy supplements that can be traced from source to shelf. The same survey found 47% wrongly believed the FDA approves supplements before sale (Amway 2024).

The FDA doesn’t approve dietary supplements before they’re sold (FDA). That’s the information gap this group of buyers has already worked out for itself.

What Do the Numbers on a Tart Cherry Supplement Label Measure?

A botanical supplement panel carries three kinds of number, and only one of them describes the dose. Once you know what you’re looking at, sorting them takes about a minute per product, and it rules out most of a shelf.

What Does “Standardized to 25%” Mean on a Supplement Label?

A standardization percentage states how much of a named active compound the extract contains by mass, so it tells you about the dose you’re taking. It’s a different kind of number from an extraction ratio like 10:1 or 52:1. A ratio only records how much raw material went into the process relative to the extract that came out. That’s a manufacturing step, not a dose, and it doesn’t reliably predict how much active compound you get.

The practical difference is that a percentage can be tested. It can be assayed against itself lot after lot. A ratio can’t be checked against a lab result. And a standardization figure is only as meaningful as its assay method, because polyphenol values differ substantially by method.

Tart-C™ is standardized to ≥25% total polyphenols, delivering ≥50 mg per 200 mg capsule. It’s assayed by Folin-Ciocalteu and reported as gallic acid equivalents (the method used in the published capsule-extract research), with the result published per lot.

On proprietary blends. A proprietary blend may look like it protects a valuable formula, but it fails a buyer trying to evaluate a dose. Only the blend total is disclosed, so any single ingredient could be present in too small a quantity to matter. That hurts most when you’re consolidating a regimen, because a blend can’t be compared with published research on any of its ingredients. Tart-C™ is one ingredient at one disclosed dose.

On extraction ratios. An extraction ratio like 10:1 or 52:1 may look like a potency measure, but it doesn’t describe the dose. It records a manufacturing step and doesn’t by itself tell you the active content. That’s a real problem for a buyer who compares labels carefully. A 52:1 extract of weak starting material could carry less polyphenol than a 4:1 extract of strong material, and nothing on either label would reveal it.

This cuts against us as well as for us. The extract used in the two capsule trials cited on this page is itself described as a 10:1 whole-fruit water extract. Its polyphenol content is known only because the researchers tested it separately and published the result. Even then, it came out at 5 to 6% in one trial and 3.2% in the other. The ratio told you nothing. The assay told you almost everything, and only for the lot tested.

Said once more, because it’s the sentence that does most of the work on a shelf: an extraction ratio describes a manufacturing step, not a dose.

How Can You Tell If a Supplement Is “Fairy Dusted”?

Fairy dusting means including an ingredient in too small a quantity to plausibly do anything, just so it can be named on the label. Four checks identify it:

1.     Is the quantity disclosed at all, or is the ingredient inside a proprietary blend where only the blend total appears?

2.     Is it the weight of the extract or of the active compound? A 500 mg extract standardized to 2% contains 10 mg of actives.

3.     Is there a standardization percentage and a stated assay method, or only an extraction ratio or whole-fruit equivalent? Neither of those describes what’s in the capsule.

4.     Does the quantity match a dose used in published research on that ingredient, in that format?

Tart-C™’s panel answers the first three: one ingredient, 200 mg of extract, and ≥25% total polyphenols delivering ≥50 mg per capsule, assayed by Folin-Ciocalteu and published per lot.

On the fourth, it isn’t a direct match. Tart-C™ provides more polyphenol per capsule than the capsule trials used, and on a different extract. The dose comparison above shows the arithmetic.

Why Does the Tart Cherry Format Matter?

Citing an ingredient’s clinical research may seem to back up any capsule made from it. That breaks down when the trials used a different format at a different amount, because processing changes both how much polyphenol there is and which compound classes it’s made of.

That processing data deserves a moment on its own. It’s one of the most overlooked findings in this ingredient’s research. Jawad et al. (2025), in Foods, analyzed five tart cherry formats by LC-MS-MS. Compared with frozen raw Montmorency fruit, total polyphenols were:

• 26% lower in juice concentrate
• 40% lower in unsweetened dried cherries
• 60% lower in freeze-dried powder
• 77% lower in sweet dried cherries

More importantly, the mix of compound classes shifts. Anthocyanins made up 18% of total polyphenols in the raw fruit and less in the processed formats. Hydroxycinnamic acids dominated the juice and dried products (66% in juice concentrate, 74 to 82% in dried cherries). Flavonols dominated the freeze-dried powder (52%).

So “tart cherry” isn’t one thing. Two products with the same botanical name and the same milligram count can be chemically different, and a trial of one isn’t automatically evidence about another.

 

Is Third-Party Tested the Same as Standardized?

No, and the difference is one of the more important ones on a supplement label.

• Third-party testing often means purity testing: confirming that a product is clean, through heavy metals, microbiological and identity analysis.
• Standardization means the extract is made to a stated quantity of a named active compound, so potency can be checked against a published figure.

A product can be perfectly clean and still leave you unable to say how much active compound you’re taking. Every supplement manufacturer must set specifications for identity, purity, strength and composition under 21 CFR 111.70. What a standardized extract adds is a published figure for the active compound that you can check against a lot result.

Tart-C™ does both. Every batch is tested for identity, as 21 CFR 111.75 requires, and for polyphenol potency, heavy metals and microbes. Tart-C™ is also third-party tested. And, separately, each lot’s total-polyphenol result is published with the method disclosed. Potency assayed, not just purity tested.

What Do Tart Cherry Polyphenols Do?

Purification makes standardization possible. Chromatographic purification removes most of the sugars, organic acids and fruit solids that make up the bulk of a whole-fruit powder. The polyphenols concentrate until a percentage specification becomes meaningful. You can’t standardize what you haven’t concentrated. That one processing choice is what lets a product carry a disclosed polyphenol percentage instead of just a ratio.

The method is printed because results differ by method. Folin-Ciocalteu, reported as gallic acid equivalents, is the method used in the published capsule-extract research and in the analytical studies that documented this category’s spread. Report a figure from a different assay and it can’t be compared with either. A number without its method is a number you can’t use. That’s why each published Certificate of Analysis shows the figure, the method and the date, not the figure alone.

What the published mechanism research describes. The next few paragraphs summarize laboratory and cell-culture research on tart cherry polyphenols and related compounds. None of it shows a benefit in people, none of it tested the Tart-C™ extract, and none of it is offered as a comparison with any medication.

Inflammatory signaling in lab studies. In cell studies, tart cherry extracts reduced nitric oxide and TNF-α release from stimulated rat immune cells (Shukitt-Hale et al. 2016). Anthocyanins from other plants have shown similar effects on NF-κB signaling in cell culture (Jeong et al. 2013). These are laboratory findings, not human results.

C-reactive protein (CRP) is made by the liver, mainly in response to IL-6 signaling (Singh et al. 2025, StatPearls). CRP is the marker most of this research has tracked, which is why it’s the marker discussed on this page rather than one chosen for convenience.

Tart-C™ supports a balanced inflammatory response.*

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Antioxidant defense works in two ways. The first is direct: some compounds neutralize free radicals on contact, and the effect is immediate and short-lived. In a test tube, a fraction of tart cherry extract (made with ethyl acetate from a methanol extract) inhibited iron-induced lipid peroxidation by 76% at 25 ppm (Wang et al. 1999). That’s a lab chemistry result, not a human outcome. It’s included to explain the mechanism, not to predict an effect.

The longer-lasting route is signaling that switches on the body’s own antioxidant defenses (the antioxidant response element, or ARE, pathway), including glutathione peroxidase. Shih et al. (2007), in the Journal of Agricultural and Food Chemistry, showed anthocyanins activating protective (phase II) enzymes through the ARE pathway in cell culture. Wangdi et al. (2022), in Medicine & Science in Sports & Exercise, gave Montmorency cherry concentrate to 10 participants. Glutathione peroxidase expression in muscle rose, and function recovered faster after muscle damage; soreness didn’t differ. That points to supporting the body’s own antioxidant defenses, not only neutralizing free radicals on contact.

Tart-C™ promotes antioxidant protection against oxidative stress.*

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Are Tart Cherry Anthocyanins Absorbed?

Barely, in their original form. The anthocyanins themselves appear in the blood at well under 1% of the amount swallowed (Fang 2014, Drug Metabolism Reviews). It’s a reasonable objection, and the one this audience raises most often.

But that isn’t the whole picture. In a human study using a labeled tracer (¹³C), about 12% of an anthocyanin dose was absorbed and circulated, mainly as metabolites (Czank et al. 2013, American Journal of Clinical Nutrition, n=8; de Ferrars et al. 2014). The compounds reaching measurable blood levels after tart cherry intake include phenolic acids produced when gut bacteria break the anthocyanins down.

Keane et al. (2016a), in the European Journal of Nutrition, studied 12 healthy men. They found protocatechuic acid and vanillic acid in blood plasma. Both peaked one to two hours after intake and were still detectable at eight hours. The study was funded in part by a Cherry Marketing Institute PhD studentship and the British Heart Foundation.

We found no evidence that an absorption enhancer increases these metabolites, so Tart-C™ doesn’t include one. That has an honest consequence: your response depends partly on how your gut bacteria convert these compounds, and that varies from person to person. So nothing here will tell you this works for everyone.

Does Tart Cherry Affect Uric Acid?

Research has looked at tart cherry and uric acid metabolism, in terms of both production and elimination, and the evidence is mixed:

• 30 days, healthy adults: tart cherry capsules or juice didn’t change uric acid (Hillman & Chrismas 2021, n=58).
• One week of capsules: no change in uric acid after a high-purine meal (Gonzalez et al. 2024, n=25).
• 48 hours, juice or 480 mg capsules: a short-lived fall (Hillman & Uhranowsky 2021, n=48).
• Pooled across trials: the effect was modest and varied substantially between studies (Zhang et al. 2026).

This is background on research you’ll see discussed elsewhere. This page makes no uric acid claim for Tart-C™. Tart-C™ is meant to complement a healthy lifestyle and your healthcare provider’s guidance, never to replace either.

Does Tart Cherry Affect Inflammatory Markers?

The overall picture is mixed. Across 21 randomized trials (n=538), mostly of tart cherry concentrate, serum CRP was modestly lower than in control groups: −0.39 mg/L (95% CI −0.74 to −0.05). The authors graded this as moderate-certainty evidence. High-sensitivity CRP and IL-6 didn’t change. TNF-α was 0.14 pg/mL lower, at very low certainty (Norouzzadeh et al. 2023, Heliyon).

In capsule form, one small trial reported lower CRP and three larger capsule trials found no change in inflammatory markers. The trial-by-trial detail, with sample sizes and funding, is in the next section.

Tart-C™ supports a balanced inflammatory response.*

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

No result on this page should be read as an expected outcome for Tart-C™.

Can Tart Cherry Extract Replace Other Supplements in a Stack?

You’re probably not adding. You’re consolidating. The useful question isn’t whether this is good, but whether it earns a slot something else currently holds.

What it can replace. Tart-C™ is one ingredient at a disclosed dose, one capsule daily. Many antioxidant and polyphenol blends (the resveratrol-plus-quercetin-plus-four-other-things category) disclose only a blend total. If the point of those bottles is polyphenol intake, a single standardized extract with a published assay gives you a polyphenol amount you can check.

What it doesn’t replace (the more useful list):

• Omega-3, which has its own large, separate evidence base and a different mechanism.
• A multivitamin, or any nutrient you take for a documented shortfall.
• Creatine, magnesium, vitamin D, or anything else whose evidence rests on its own trials rather than on polyphenol intake.
• A broad-spectrum antioxidant. Different polyphenol classes act on different targets, and one extract doesn’t stand in for a varied diet.

Naming those limits is what earns the claims being made. A product that replaces everything replaces nothing you can reason about.

If you’re curious about how you respond, talk with your healthcare provider.

What Does the Human Research on Tart Cherry Show?

This section describes published research on tart cherry extract, juice or powder in general. Sample sizes and funding sources are stated every time, including where that weakens the picture.

Capsule Research on a Different Tart Cherry Extract

The two positive capsule trials used a different tart cherry extract, analyzed by the same Folin-Ciocalteu method Tart-C™ uses, at lower polyphenol amounts than one Tart-C™ capsule.

Inflammatory balance, capsule format. Jäger et al. (2026) studied 10 adults aged 18 to 45 with a BMI of 25 to 30.

• CRP: fell 23% from baseline (5.9 to 4.6 mg/L) over four weeks on the extract, and didn’t change on placebo (5.8 to 6.1).
• Uric acid: fell 37% (7.0 to 4.4 mg/dL), compared with 6.2 to 6.5 on placebo.
• Significance: both day-28 differences were significant (p<0.001). Single doses changed neither marker.
• Design: double-blind, placebo-controlled crossover with a 14-day washout, conducted in Bangalore, India.
• Funding and authors: funded by the extract’s maker. The company’s founder, a named patent inventor, was a co-author; the paper states he had no role in running or analyzing the study. (3)

Ten participants is a small study. An effect seen in ten people isn’t a prediction about you, and four weeks in ten people is too small to establish the safety profile of anything.

Antioxidant defense, capsule format, in people. Hooper et al. (2021) studied 13 men with at least six months of barbell back squat experience, in a randomized, counterbalanced crossover funded by industry.

• Protein carbonyls: seven days of pre-loading cancelled out the rise in protein carbonyls (a marker of oxidative stress) seen on placebo after exercise: +0.4 on placebo vs −0.4 nmol/mg on tart cherry immediately afterward (p<0.001). The authors noted that protein carbonyls may be a more sensitive marker of oxidative stress than those used in earlier work.
• Other results: CK-MB, a marker of muscle stress, was lower at 1 hour (p=0.006), and handgrip strength was preserved at 24 hours (p=0.017).
• No difference: muscle soreness and jump power.
• Limitation: the authors note their exercise protocol was mild enough that it didn’t reduce performance, which limits what the trial can say about recovery.

Supporting human antioxidant evidence.

• Bowtell et al. (2011, n=10, concentrate): Bowtell et al. (2011), in Medicine & Science in Sports & Exercise, found a smaller rise in protein carbonyls and faster strength recovery. That’s the same measure Hooper used ten years later in capsule form.
• Howatson et al. (2010, n=20 marathon runners, juice): Howatson et al. (2010), in the Scandinavian Journal of Medicine & Science in Sports, reported total antioxidant status about 10% higher, lower lipid peroxidation at 48 hours, and faster strength recovery. Protein carbonyls didn’t differ between groups.
• Chai et al. (2019, twelve-week juice trial, adults aged 65 to 80): Chai et al. (2019) reported a significant between-group CRP difference (p=0.03), lower malondialdehyde (group effect p=0.0025), and higher OGG1 DNA-repair activity (p<0.0001). TNF-α, 8-OHdG and oxidized LDL didn’t differ. Of 37 randomized, 34 completed; funded by the Cherry Marketing Institute.

Is more better? A dose-response hasn’t been established. Norouzzadeh et al. (2023) reported a dose-response for CRP across 21 trials, mostly of concentrate, but no capsule trial has tested more than one dose. Neither point is an argument for selling you more.

What Did the Null Trials Find?

• Largest capsule-arm trial, null. Thirty days of tart cherry capsules or juice in 58 healthy adults changed nothing in gut microbiome composition, CRP (p=0.42), TNF-α, ESR, uric acid or blood sugar control. Double-blind, registered NCT04467372, funded by the Cherry Marketing Institute (Hillman & Chrismas 2021). This matters because the mechanism described on this page runs through conversion by gut bacteria.
• Capsules in the 30-to-60 age range, null. Seven days of 960 mg/day capsules in 25 adults aged 30 to 60 had no effect on uric acid or cytokines after a meal designed to raise uric acid. Double-blind crossover, industry-funded (Gonzalez et al. 2024).
• Short-term dosing, mixed. Forty-eight hours of once- or twice-daily juice or 480 mg capsules in 48 participants produced a short-lived fall in uric acid (about 8% on average). It didn’t change high-sensitivity CRP or antioxidant capacity. Funded by a Marywood University research award (Hillman & Uhranowsky 2021).
• Three months in middle-aged adults, null. Adults averaging 48 years old took juice concentrate for three months, with no between-group effect on vascular or metabolic markers, including high-sensitivity CRP. Of 56 randomized, 50 completed; funded by Northumbria University and the Cherry Research Committee (Kimble et al. 2021).
• Pooled uric acid effect. Across four randomized trials (392 participants), the pooled effect was modest (SMD −0.22; 95% CI −0.43 to −0.01), with substantial variation between studies (Zhang et al. 2026).
• Recovery, capsule and powder, null. A 1,000 mg/day capsule trial found no effect on recovery from exhaustive exercise (Ortega et al. 2023). A 500 mg/day powder trial found no effect on performance recovery after repeated sprints (Hagele et al. 2026).
• Body composition, null. Six randomized trials in 126 participants found no effect on body weight, BMI, waist circumference or fat mass (Amini et al. 2023).
• Narrative review. A 2026 review concluded that proposed mechanisms for this ingredient didn’t consistently translate into functional benefits (Kim 2026).

What this adds up to. The positive findings are real but modest, and they come mostly from small trials and non-capsule formats. The null findings are real too. Taken together, they support the careful wording used here, which is support rather than a promised result.

No research has been conducted on the Tart-C™ extract itself. Not a pilot, not an observational study, nothing.

What we can document is the testing:

• USDA Organic certification by Oregon Tilth.
• cGMP manufacturing under 21 CFR Part 111.
• Identity testing on every batch, as 21 CFR 111.75 requires.
• A published Certificate of Analysis for each lot, showing the total-polyphenol result by Folin-Ciocalteu as gallic acid equivalents.
• Batch testing for heavy metals and microbes.
• Third-party testing.

Which Tart Cherry Benefits Does This Page Not Claim, and Why?

Seven, with the reason for each. Several get real search volume, and several are claimed by other products in this category.

Weight. No weight or weight-management claim is made for Tart-C™. The research used different formats and amounts, and one 12-week juice trial reported BMI higher than in the control group (+1.06, p=0.02; Chai et al. 2018).

Body composition. No body composition claim is made for Tart-C™. Six randomized trials in 126 participants found no effect on body weight, BMI, waist circumference or fat mass (Amini et al. 2023).

Cholesterol. No cholesterol or lipid claim is made for Tart-C™. One 12-week juice trial reported mixed lipid and blood sugar results. Glucose, triglycerides and BMI were higher in the cherry group than in a control group matched for calories and sugar (Chai et al. 2018). Because of that matching, the rises can’t be blamed on the sugar in the juice. That makes them harder to explain, not easier, and a result that has to be set aside even within its own study isn’t a basis for a claim.

Blood pressure. No blood pressure claim is made for Tart-C™. The same single juice trial, with the same unexplained metabolic results, isn’t a basis for a claim about a purified capsule extract at a different dose.

Cognition. No cognitive claim is made for Tart-C™. Keane et al. (2016b), in the British Journal of Nutrition, found short-term changes in vascular function but no improvement in cognitive performance.

Kidney markers. Single small trials. Not claimed.

Bone turnover. Single small trials. Not claimed.

Every trial above is listed with its sample size and funding source, and the ones that found nothing sit alongside the ones that did.

How Should You Choose a Tart Cherry Extract?

Three things to know first, because a framework from an interested party should come with its limits stated.

The research is on tart cherry in general. The positive capsule trials are small and industry-funded, and they used an extract with a different composition. If a trial of the finished product is your threshold, this product doesn’t meet it yet.

No anthocyanin figure is published, because we haven’t verified one for this extract. Some tart cherry products list an anthocyanin percentage. We’d rather print nothing than print something we can’t prove.

The specification isn’t proprietary. There’s no patent and no proprietary molecule here. The advantage is documented, not structural, and anyone telling you otherwise about a commodity specification is overselling.

What to Check When You Choose a Botanical Extract

For knowing the active quantity

✓ What Tart-C™ offers: a disclosed total-polyphenol specification, ≥50 mg per capsule, and a published per-lot Certificate of Analysis with the method stated.

○ Alternative: products that state a standardized active figure without a published per-lot result. Better than a ratio, but you can’t check each batch.

✗ Avoid: extraction ratios and whole-fruit equivalents. A ratio can’t be checked against a lab result.

For organic as a requirement

✓ What Tart-C™ offers: USDA Organic certification, plus a total-polyphenol percentage and amount on the label.

○ Alternative: certified-organic ratio extracts. They meet the sourcing requirement but disclose no actives.

✗ Avoid: “natural” and “clean” label language without a certifying body.

For verification you can do yourself

✓ What Tart-C™ offers: a QR-linked per-lot assay result showing the figure, the method and the date.

○ Alternative: Certificate of Analysis on request. Real, but a hurdle most buyers never get past.

✗ Avoid: brand-level testing claims with no lot-level document.

For evidence that matches the product

✓ What Tart-C™ offers: no product in this category wins this row outright. Tart-C™ publishes the assay figure, the method, the sample sizes, the funding sources and the trials that found nothing, so you can judge the fit yourself.

○ Alternative: branded ingredients with their own trials. They have the strongest clinical documentation in the category, and Tart-C™ doesn’t dispute it.

✗ Avoid: claims borrowed from a different format at a different dose, without the mismatch disclosed.

For consolidating a stack

✓ What Tart-C™ offers: one ingredient at a disclosed dose, one capsule daily.

○ Alternative: other single-ingredient standardized extracts.

✗ Avoid: proprietary blends that disclose only a blend total.

Clinical documentation as the main criterion

○ Consider: an ingredient with its own clinical trials, if that’s your deciding factor. It’s a sound basis for choosing.

Tart cherry ingredients with their own capsule trials have the strongest clinical documentation in the category. What Tart-C™ offers instead is USDA Organic certification, and a polyphenol figure you can check for every lot.

What Does the Price Cover?

Tart-C™ is priced for what it costs to make and test, not for promotions.

$36.99 a bottle: about $0.62 a day at one capsule, or $1.23 a day at the two-capsule maximum, for ≥50 mg of measured polyphenols per capsule. If you’re consolidating a $200–400 monthly stack, one capsule a day comes to roughly $19 a month for an item you can check against a lab result.

Itemized, the cost covers:

• 200 mg of chromatographically purified organic tart cherry extract per capsule, standardized to ≥25% total polyphenols
• ≥50 mg of total polyphenols per capsule, measured rather than asserted
• A published Certificate of Analysis for each lot, with the assay figure, the method and the date, QR-linked from the bottle
• Identity testing on every batch, as 21 CFR 111.75 requires
• Batch testing for polyphenol potency, heavy metals and microbes
• Third-party testing
• A page of evidence with sample sizes, funding sources and the trials that found nothing
• A published list of the benefits assessed and not claimed on this page (currently seven), with the reason for each

Learn More About Tart-C™

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Method, Ingredients and Open Items

How Is Tart-C™ Tested for Polyphenols?

Total polyphenols are measured by the Folin-Ciocalteu method and reported as gallic acid equivalents. The method measures total reducing capacity against a gallic acid standard. Most of that signal comes from polyphenols, but other reducing compounds, such as sugars and ascorbic acid, can add to it. That’s one reason purification, which removes most of the sugars, makes the figure more meaningful. The method also isn’t specific in the way an HPLC measurement of a named compound is.

It’s used here because it’s the method used in the published capsule-extract research and in the analytical studies that measured this category. That makes the number comparable rather than decorative. A figure from a different assay isn’t interchangeable with this one. Any brand that reports a polyphenol percentage without naming its method has given you a number you can’t use.

The 2021 review by Sabou et al. also found that Folin-Ciocalteu tends to report lower values than HPLC. That’s worth knowing when you compare our figure with a compound-specific one.

What’s in the Capsule?

Each capsule contains 200 mg of organic tart cherry extract in an organic pullulan capsule. Other ingredients: organic tapioca flour and organic rice hulls. Tart-C™ is USDA Organic certified by Oregon Tilth.

These compounds are sensitive to heat and pH, which is why polyphenol potency is tested for every batch, not just once during development.

What Hasn’t Been Verified Yet?

We haven’t yet published a compound-class profile for this extract by HPLC-DAD or LC-MS, confirming which classes survive purification. Until we do, no anthocyanin figure is printed.

Some context while that’s open: in the five-format study, three classes (hydroxycinnamic acids, flavonols and anthocyanins) made up 87 to 99% of total polyphenols. So the question of what survives purification is a real one, not a formality.

We publish this as an open item rather than leave it out, because a list of what a brand doesn’t yet know is part of what it should disclose.

Is Tart-C™ Safe to Take?

Directions: take 1 capsule daily with food. Don’t exceed 2 capsules (400 mg of extract) daily.

Two capsules provide ≥100 mg of total polyphenols. That’s more polyphenol than either of the capsule trials cited here used. Those trials reported no supplement-related side effects over seven days to four weeks (Hooper et al. 2021; Jäger et al. 2026). But longer-term data at this amount aren’t available, and at 13 and 10 participants, neither trial is large enough to establish a safety profile.

Talk to your healthcare provider before use if you:

• have kidney disease or reduced kidney function
• take NSAIDs regularly
• are pregnant or nursing
• take any medication

If you’re scheduled for surgery, tell your healthcare provider about all the supplements you take. Not intended for children.

 

Frequently Asked Questions

What Is Folin-Ciocalteu, and Why Does the Method Matter?

Folin-Ciocalteu is a color-based lab test that measures a sample’s total reducing capacity against a gallic acid standard, hence “gallic acid equivalents.” It measures the whole polyphenol pool rather than specific compounds, so it doesn’t tell you the mix within that pool, and non-phenolic compounds can add to the signal.

The method matters because polyphenol values differ substantially between assays. A percentage from one method can’t be compared with a percentage from another, or with published research that used a different method. Folin-Ciocalteu reported as gallic acid equivalents is the method used in both the capsule-extract trials and the analytical studies of this category. Naming it is what makes the figure usable.

Why Doesn’t Tart-C™ Include an Absorption Enhancer?

Because we found no evidence that one helps with these compounds. Piperine and similar enhancers appear in many botanical products based on research done with different molecules. The compounds that reach the blood here are mainly phenolic acids made by gut bacteria, not the original anthocyanins, and we found no published work showing that an enhancer increases them. Adding an unproven second ingredient would also break the single-ingredient approach, which is the point of the product.

Has Tart-C™ Itself Been Studied?

No. No trial has been conducted on the Tart-C™ extract itself. The research cited on this page is on tart cherry extract, juice and powder in general. That includes two small, industry-funded capsule trials of a different extract, one reporting lower CRP and one reporting a smaller rise in protein carbonyls after exercise. It also includes three larger capsule trials that found no change in inflammatory markers.

Does Tart Cherry Work for Everyone?

No. The compounds that matter depend on how each person’s gut bacteria convert them, which varies, so response varies too. The published evidence is mixed rather than uniform:

• A pooled analysis of 21 trials found a modest effect on CRP, at moderate certainty, with no change in high-sensitivity CRP or IL-6.
• The strongest supporting trials are small and industry-funded.
• The larger capsule trials found no change.
• The pooled uric acid effect varies substantially between studies.

A brand that tells you a botanical extract works for everyone is either not reading its own research or counting on you not to.

Is Tart-C™ Right for You?

In our September 2026 review of US retail and Amazon listings, Tart-C™ was the only finished tart cherry supplement we found that is both USDA Organic certified and labeled with a total-polyphenol percentage and amount. (1)

Learn More About Tart-C™· Browse the Resource Library

When Tart-C™ Is the Right Choice

✓ USDA Organic certification is a requirement, not just a preference.

✓ Knowing the measured amount of the active compound matters more to you than the size of the number on the front panel.

✓ A published per-lot Certificate of Analysis with the assay method stated is part of how you decide.

✓ You prefer a single disclosed ingredient to a multi-ingredient antioxidant or polyphenol blend.

✓ You want sample sizes, funding sources and null trials printed alongside the positive ones.

✓ You’re consolidating a stack, and everything that stays has to hold up to questions.

When Tart-C™ Is Not the Right Choice

○ A trial of the specific ingredient is your deciding factor. Options with their own trials win that comparison.

○ Anthocyanin content is your deciding factor. No anthocyanin figure is published because none has been verified, and other products list one.

○ Total polyphenol per serving is your only criterion. A concentrate serving carries more, and the published exercise-performance thresholds sit far above 50 mg.

○ Your goal is weight, body composition, cholesterol, blood pressure or cognition. None is claimed on this page; each was assessed and deliberately left out.

○ Cost per day is your main criterion. Unstandardized organic tart cherry capsules often cost less per day, and this product doesn’t compete on price.

If two or more of those apply to you, another product will probably suit you better. A framework that recommends its author’s product under every condition isn’t a framework.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary.

All cited research describes published studies on tart cherry extract, juice or powder in general, or on related compounds where noted. No research has been conducted on Tart-C™ specifically. No anthocyanin figure is published because none has been verified.

Tart-C™ is meant to complement a healthy lifestyle and your healthcare provider’s guidance, never to replace either. If you have kidney disease or reduced kidney function, take NSAIDs regularly, are pregnant or nursing, or take any medication, talk to your healthcare provider before use. Don’t exceed 2 capsules daily.

Notes

(1) Basis for the “only product” statement. In September 2026, Triquetra Health reviewed US retail and Amazon listings for tart cherry capsules and powders. Across eleven tart cherry offers read in September 2026, none printed a polyphenol percentage or amount. The statement is limited to finished supplements that are both USDA Organic certified and labeled with a total-polyphenol percentage and amount. We’ll update or withdraw it if we find a competing product that meets both conditions.

(2) Basis for the dose comparison. Two published capsule trials gave 500 mg/day of the same tart cherry extract. Its total polyphenol content, measured by Folin-Ciocalteu, was 5 to 6% in one trial (about 25 to 30 mg/day; Hooper et al. 2021) and 3.2% in the other (about 16 mg/day; Jäger et al. 2026). The comparison is of measured total polyphenol amount by the same lab method. It isn’t a comparison of clinical outcomes. Taking more polyphenol than was studied isn’t known to produce an equal or greater effect, and Tart-C™ has not been clinically tested.

(3) Jäger et al. (2026) trial details.

• Design: randomized, double-blind, placebo-controlled crossover.
• Participants: 10 healthy adults (6 men, 4 women), mean age 34.9 years, BMI 25 to 30.
• Protocol: 500 mg/day of tart cherry extract or placebo for four weeks per phase, with a 14-day washout. Conducted in Bangalore, India; registered as CTRI/2024/11/077440.
• Funding and authors: funded by the extract’s manufacturer. A co-author is the manufacturer’s founder and a named inventor on related patent applications; the paper states he had no role in running or analyzing the study.

Scientific References & Citations

Every source below describes published research on tart cherry extract, juice or powder in general, or on related compounds where noted.

Amini, M. R., Payandeh, N., Sheikhhossein, F., Shahinfar, H., Pourreza, S., & Hekmatdoost, A. (2023). Effect of tart cherry juice consumption on body composition and anthropometric measures: A systematic review and meta-analysis of randomized controlled trials. Clinical Nutrition Research, 12(1), 65–76. https://doi.org/10.7762/cnr.2023.12.1.65

Bowtell, J. L., Sumners, D. P., Dyer, A., Fox, P., & Mileva, K. N. (2011). Montmorency cherry juice reduces muscle damage caused by intensive strength exercise. Medicine & Science in Sports & Exercise, 43(8), 1544–1551. https://doi.org/10.1249/MSS.0b013e31820e5adc

Chai, S. C., Davis, K., Wright, R. S., Kuczmarski, M. F., & Zhang, Z. (2018). Impact of tart cherry juice on systolic blood pressure and low-density lipoprotein cholesterol in older adults: A randomized controlled trial. Food & Function, 9(6), 3185–3194. https://doi.org/10.1039/c8fo00468d

Chai, S. C., Davis, K., Zhang, Z., Zha, L., & Kirschner, K. F. (2019). Effects of tart cherry juice on biomarkers of inflammation and oxidative stress in older adults. Nutrients, 11(2), 228. https://doi.org/10.3390/nu11020228

Czank, C., Cassidy, A., Zhang, Q., Morrison, D. J., Preston, T., Kroon, P. A., Botting, N. P., & Kay, C. D. (2013). Human metabolism and elimination of the anthocyanin, cyanidin-3-glucoside: A ¹³C-tracer study. The American Journal of Clinical Nutrition, 97(5), 995–1003. https://doi.org/10.3945/ajcn.112.049247

de Ferrars, R. M., Czank, C., Zhang, Q., Botting, N. P., Kroon, P. A., Cassidy, A., & Kay, C. D. (2014). The pharmacokinetics of anthocyanins and their metabolites in humans. British Journal of Pharmacology, 171(13), 3268–3282. https://doi.org/10.1111/bph.12676

Fang, J. (2014). Bioavailability of anthocyanins. Drug Metabolism Reviews, 46(4), 508–520. https://doi.org/10.3109/03602532.2014.978080

Gonzalez, D. E., Kendra, J. A., Dickerson, B. L., Yoo, C., Ko, J., McAngus, K., Martinez, V., Leonard, M., Johnson, S. E., Xing, D., Sowinski, R. J., Rasmussen, C. J., & Kreider, R. B. (2024). Effects of acute and one-week supplementation with Montmorency tart cherry powder on food-induced uremic response and markers of health: A proof-of-concept study. Nutrients, 16(19), 3391. https://doi.org/10.3390/nu16193391

Hagele, A. M., Levers, K. S., Holley, K. F., Schrautemeier, A. C., Krieger, J. M., Iannotti, J. M., Gaige, C. J., Jäger, R., & Kerksick, C. M. (2026). Impact of powdered tart cherry supplementation on performance recovery following repeated sprint exercise. Nutrients, 18(3), 443. https://doi.org/10.3390/nu18030443

Hillman, A. R., & Chrismas, B. C. R. (2021). Thirty days of Montmorency tart cherry supplementation has no effect on gut microbiome composition, inflammation, or glycemic control in healthy adults. Frontiers in Nutrition, 8, 733057. https://doi.org/10.3389/fnut.2021.733057

Hillman, A. R., & Uhranowsky, K. (2021). Acute ingestion of Montmorency tart cherry reduces serum uric acid but has no impact on high sensitivity C-reactive protein or oxidative capacity. Plant Foods for Human Nutrition, 76(1), 83–89. https://doi.org/10.1007/s11130-021-00879-7

Hooper, D. R., Orange, T., Gruber, M. T., Darakjian, A. A., Conway, K. L., & Hausenblas, H. A. (2021). Broad spectrum polyphenol supplementation from tart cherry extract on markers of recovery from intense resistance exercise. Journal of the International Society of Sports Nutrition, 18(1), 47. https://doi.org/10.1186/s12970-021-00449-x

Howatson, G., McHugh, M. P., Hill, J. A., Brouner, J., Jewell, A. P., van Someren, K. A., Shave, R. E., & Howatson, S. A. (2010). Influence of tart cherry juice on indices of recovery following marathon running. Scandinavian Journal of Medicine & Science in Sports, 20(6), 843–852. https://doi.org/10.1111/j.1600-0838.2009.01005.x

Jäger, R., Purpura, M., Balcombe, S. T., Godavarthi, A., Reddy, S. A., Vasenina, E., & Tinsley, G. M. (2026). Effects of tart cherry extract supplementation on plasma urate and C-reactive protein levels in healthy adults: A randomized controlled trial. Journal of Dietary Supplements, 23(1), 42–57. https://doi.org/10.1080/19390211.2025.2589787

Jawad, M., Talcott, S. T., Hillman, A. R., & Brannan, R. G. (2025). A comprehensive polyphenolic characterization of five Montmorency tart cherry (Prunus cerasus L.) product formulations. Foods, 14(7), 1154. https://doi.org/10.3390/foods14071154

Jeong, J.-W., Lee, W. S., Shin, S. C., Kim, G.-Y., Choi, B. T., & Choi, Y. H. (2013). Anthocyanins downregulate lipopolysaccharide-induced inflammatory responses in BV2 microglial cells by suppressing the NF-κB and Akt/MAPKs signaling pathways. International Journal of Molecular Sciences, 14(1), 1502–1515. https://doi.org/10.3390/ijms14011502

Keane, K. M., Bell, P. G., Lodge, J. K., Constantinou, C. L., Jenkinson, S. E., Bass, R., & Howatson, G. (2016a). Phytochemical uptake following human consumption of Montmorency tart cherry (Prunus cerasus L.) and influence of phenolic acids on vascular smooth muscle cells in vitro. European Journal of Nutrition, 55(4), 1695–1705. https://doi.org/10.1007/s00394-015-0988-9

Keane, K. M., Haskell-Ramsay, C. F., Veasey, R. C., & Howatson, G. (2016b). Montmorency tart cherries (Prunus cerasus L.) modulate vascular function acutely, in the absence of improvement in cognitive performance. British Journal of Nutrition, 116(11), 1935–1944. https://doi.org/10.1017/S0007114516004177

Kim, J. (2026). Tart cherry supplementation for exercise recovery: An evidence-informed narrative review and applied monitoring framework. Physical Activity and Nutrition, 30(1), 63–71. https://doi.org/10.20463/pan.2026.0009

Kimble, R., Keane, K. M., Lodge, J. K., & Howatson, G. (2021). The influence of tart cherry (Prunus cerasus, cv Montmorency) concentrate supplementation for 3 months on cardiometabolic risk factors in middle-aged adults: A randomised, placebo-controlled trial. Nutrients, 13(5), 1417. https://doi.org/10.3390/nu13051417

Norouzzadeh, M., Hasan Rashedi, M., Shahinfar, H., & Rahideh, S. T. (2023). Dose-dependent effect of tart cherry on blood pressure and selected inflammation biomarkers: A GRADE-assessed systematic review and meta-analysis of randomized controlled trials. Heliyon, 9(9), e19987. https://doi.org/10.1016/j.heliyon.2023.e19987

Ortega, D. G., Coburn, J. W., Galpin, A. J., & Costa, P. B. (2023). Effects of a tart cherry supplement on recovery from exhaustive exercise. Journal of Functional Morphology and Kinesiology, 8(3), 121. https://doi.org/10.3390/jfmk8030121

Rickards, L., Lynn, A., Barker, M. E., Russell, M., & Ranchordas, M. K. (2022). Comparison of the polyphenol content and in vitro antioxidant capacity of fruit-based nutritional supplements commonly consumed by athletic and recreationally active populations. Journal of the International Society of Sports Nutrition, 19(1), 336–348. https://doi.org/10.1080/15502783.2022.2091412

Sabou, V. R., O’Leary, M. F., Liu, Y., Brown, P. N., Murch, S., & Bowtell, J. L. (2021). Review of analytical methods and reporting of the polyphenol content of tart cherry supplements in human supplementation studies investigating health and exercise performance effects: Recommendations for good practice. Frontiers in Nutrition, 8, 652094. https://doi.org/10.3389/fnut.2021.652094

Shih, P.-H., Yeh, C.-T., & Yen, G.-C. (2007). Anthocyanins induce the activation of phase II enzymes through the antioxidant response element pathway against oxidative stress-induced apoptosis. Journal of Agricultural and Food Chemistry, 55(23), 9427–9435. https://doi.org/10.1021/jf071933i

Shukitt-Hale, B., Kelly, M. E., Bielinski, D. F., & Fisher, D. R. (2016). Tart cherry extracts reduce inflammatory and oxidative stress signaling in microglial cells. Antioxidants, 5(4), 33. https://doi.org/10.3390/antiox5040033

Singh, B., Goyal, A., & Patel, B. C. (2025). C-reactive protein: Clinical relevance and interpretation. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK441843/

Wang, H., Nair, M. G., Strasburg, G. M., Booren, A. M., & Gray, J. I. (1999). Antioxidant polyphenols from tart cherries (Prunus cerasus). Journal of Agricultural and Food Chemistry, 47(3), 840–844. https://doi.org/10.1021/jf980936f

Wangdi, J. T., O’Leary, M. F., Kelly, V. G., Jackman, S. R., Tang, J. C. Y., Dutton, J., & Bowtell, J. L. (2022). Tart cherry supplement enhances skeletal muscle glutathione peroxidase expression and functional recovery after muscle damage. Medicine & Science in Sports & Exercise, 54(4), 609–621. https://doi.org/10.1249/MSS.0000000000002827

Zhang, Z., Feng, Z., Yan, W., Wu, T., Xia, J., Yu, J., Yang, J., Wang, Y., & Sun, G. (2026). Tart cherry intake and serum uric acid: Meta-analysis of randomized controlled trials and evidence from network pharmacology. Asia Pacific Journal of Clinical Nutrition, 35(3), 451–462. https://doi.org/10.6133/apjcn.202606_35(3).0008

Regulatory and Market Sources

Amway. (2024, November 11). “Habits and Healthspan” U.S. survey reveals barely half of consumers know that supplements are not approved by FDA. https://www.amwayglobal.com/newsroom/habits-and-healthspan-u-s-survey-reveals-barely-half-of-consumers-know-that-supplements-are-not-approved-by-fda/

Current Good Manufacturing Practice in Manufacturing, Packaging, Labeling, or Holding Operations for Dietary Supplements, 21 C.F.R. § 111.70 (2026). https://www.law.cornell.edu/cfr/text/21/111.70

Current Good Manufacturing Practice in Manufacturing, Packaging, Labeling, or Holding Operations for Dietary Supplements, 21 C.F.R. § 111.75 (2026). https://www.law.cornell.edu/cfr/text/21/111.75

FMI – The Food Industry Association. (2020, June 23). New research from FMI and Label Insight reveals omnichannel grocery shoppers see transparency as essential across in-store and online shopping channels. https://www.fmi.org/newsroom/news-archive/view/2020/06/23/new-research-from-fmi-and-label-insight-reveals-omnichannel-grocery-shoppers-see-transparency-as-essential-across-in-store-and-online-shopping-channels

Pure Branding. (n.d.). The ROI of transparency: Vitamin & supplement edition. https://purebranding.com/roi-of-transparency-supplements/

Trust Transparency Center. (n.d.). Supplement consumers value these signals of transparency. https://trusttransparency.com/supplement-consumers-value-these-signals-of-transparency/

U.S. Food and Drug Administration. (n.d.). Questions and answers on dietary supplements. https://www.fda.gov/food/information-consumers-using-dietary-supplements/questions-and-answers-dietary-supplements