If you are one of the 30 percent of stutterers who benefit from B1, you are lucky because B1 may solve your stuttering problem or improve it significantly, i'll explain how to take it: In a nutshell - 300mg of B1 thiamine hcl three times a day (3x100mg) together with a capsule of magnesium (not cheap one) taken with food. Avoid coffee, tea, chocolate, raw fish. It works in 30% of people, if you don't see result in 2 weeks then it's not working for you. Start at 300mg of B1 thiamine hcl which is water soluble form and you can't overdose with it (you pee it out) compared to fat soluble forms. Three times a day taken with food (3x100mg). Later if you don't see any results you can increase dosage to 1200mg per day which is maximum that body can utilise (even 5000-7000mg wasn't toxic, maybe after long time it can) Magnesium is recommended to be taken too, one of the best forms is magnesium bisglycinate/glycinate (no side effects, good absorption) or combination of more forms, avoid anorganic form of magnesium like oxide or lactate (google for more info). You don't have to use it at first and see if just B1 is working or start using it together from beginning. Dosage is 300-400mg three times a day together with B1. I'm not sure if they meant 300mg of elemental magnesium (just pure magnesium), because magnesium is always attached to something, in this case to amino acid glycine and in order to get 300mg of elemental magnesium from bisglycinate form you would need 2150mg of it (14% of bisglycinate is elemental magnesium). 300mg of bisglycinate seems low and 2150 seems quite a lot, but most of the people are deficient in magnesium, it's hard to get from food and it's easily depleted in stressful situation. Another important step is avoid food containing high amounts of tannins which inhibits B1. Avoid coffee, tea (herbal are okay), alcohol (mainly wine), chocolate and raw fish... these are most mentioned. If you will not see effects in two weeks then it basically not working, but you may try to increase dosage up to 1200mb of B1 per day and try for another two weeks. You can find all the information here http://stuttersense.blogspot.com/2013/08/faq-about-thiamine-vitamin-b1-and.html?m=1 My experience - I did it for two weeks with 300mg of B1 per day also with magnesium and without foods high in tannins. Before I started I had one of those periods when I stutter a more than usual and after using B1 it got better, to normal state as before (maybe a bit better) so it probably didn't work as I just naturally got back to normal state of stuttering. Or it helped with that bad time period of stuttering, or I did something wrong or dose wasn't high enough. Today I'm day or two without B1, had coffee and chocolate and so far nothing changed. (This isn't my case but i take from someone who explain how to take B1 and mg and explain his case and what happened to him)