They are 20mcg per tab. I usuall start of with 40mcg and then up in two days to 80mcg then up to 100mcg. I do 2 days on 2 off. Some ppl go higher on the mcg, but ramping up to 100mcg then staying there till im done and then ramping down seems to work for me. To be honest, because i do 2 on 2 off, i don't even ramp down, i just stop, and never had a prob, but i do ramp up. They look legit to me from Mexico. Oh, don't forget to take taurine with it. I usually take 2gm per day. This is a supplement you can get at most vitamin stores. I get the 1gm caps. Nutritiongeeks.com sells the Now brand cheap.