I’m a few weeks into taking this supplement. Around a week after I started it, I woke up one morning will tingling in my arms and toes. It almost fell like they were falling asleep, only instead of losing sensation, I was gaining it! The tips of my toes were numb since I was 18 (I’m 49) and the outsides of my arms for about 10 years. The doctor told me it was carpal tunnel… now I’m thinking I’ve been b-12 deficient all this time! The tingling resolved within a day or so, and I’m enjoying feeling my extremities again! Wish I knew I needed methylated B-12 years ago!!!!