This seems like a very interestering substance.

"Follistatin is being studied for its role in regulation of muscle growth in mice, as an antagonist to myostatin (also known as GDF-8, a TGF superfamily member) which inhibits excessive muscle growth. Lee & McPherron demonstrated that inhibition of GDF-8, either by genetic elimination (knockout mice) or by increasing the amount of follistatin, resulted in greatly increased muscle mass. In 2009, research with macaque monkeys demonstrated that regulating follistatin via gene therapy also resulted in muscle growth and increases in strength. This research paves the way for human clinical trials, which are hoped to begin in the summer of 2010 on Inclusion body myositis."

Here's a pic of animal-trials with mice: http://www.who-sucks.com/wp-content/uploads/icons//2007/07/follistan-pic...

I've seen in some peptide source reviews that some members bought it. So maybe someone can give me some Input on this or even has experience?

Some users on UK boards already tried it but the reviews are very contradictory. Some users report 1kg lean weight gain per day others say that it has absolutely no effect (difference between fake and legit follistatin?) . But the threads are at least 2 years old and the availability is much better now.

I always read dosage 10 i.u. but this is mainly because of the short halflife of 10 days so they just mix it with 1ml bac. water and take it 10 days. So would i have more benefits if i took 20 i.u. for example or is it another compund where you just have to guess the dosage?

I'd really like to know if it is worth to give it a try.