In the market, what you will usually find are 20 mcg Clenbuterol tablets but you would sometimes notice that some are selling tablets at dosages of 40 mcg. These 40 mcg pills find their application usually in the veterinary field for bronchodilation and treatment of asthma usually for horses. Bodybuilders, athletes or those who just want to lose some weight do not usually use the 40 mcg tablets since these do not offer much flexibility in doing the Clen cycle which is usually 3 weeks on 3 weeks off. Another reason is that some users are used to increasing their dosages by increments of 20 day by day. With 40 mcg tablets, you can still do this but you might have to split the pill in half.