Follistatin is involved in muscle growth, inflammation, and fertility. While it has gained attention in bodybuilding circles, the benefits of follistatin on muscle growth may not be all they’re cracked up to be. Read on to learn more about follistatin and how you can boost its levels with foods and supplements. Follistatin is a compound made of protein and sugar molecules – a glycoprotein. As shown by studies in rats and mice, follistatin is primarily produced in the liver, although it can also be found in almost all body tissues. Follistatin increases in muscle tissue in response to muscle damage and plays a role in promoting cell growth throughout the body. Follistatin 344 (FS-344): The most basic form of follistatin. It is primarily used in gene therapy, where the gene that helps create more follistatin is injected into the body using specially-designed viruses. Different parts of the body can then convert this “general” form of follistatin into more specific types in order to target different parts of the body.