Buy 98%+ Purity Bodybuilding Peptide FST-344 Follistatin 344 (1mg / vial) Powder Online   Follistatin 344 Description Follistatin 344 was initially identified as a follicle-stimulating hormone inhibiting substance found in ovarian follicular fluid. FST is a high-affinity activin binding protein that can act as an activin antagonist. Two alternatively spliced follistatin mRNAs exist, encoding mature FS with 288 amino acid residues (FS-288) and 315 …