Follistatin-344 is a full-sized synthetic analogue of naturally occurring Follistatin. It neutralizes the effects of myostatin, activin, and follicle stimulating hormone (FSH). In animal studies, these actions lead to increased muscle mass (both hypertrophy and hyperplasia), reduced scar formation, and inhibited certain inflammatory responses. Follistatin-344 can be altered by the body to produce other variants of Follistatin.