Follistatin 344
aka FS-344
Mechanism
Follistatin 344 is a recombinant form of the naturally-occurring glycoprotein (344-residue splice variant) that inhibits activin and myostatin signaling. Clinical validation exists ONLY through small AAV gene-therapy phase 1/2 trials in Becker muscular dystrophy; recombinant injectable protein sold on the grey market has no clinical evidence. NOT FDA-approved. WADA-prohibited (myostatin inhibitor) and banned in competitive sport.
Identification
| Sequence | MVRARHQPGGLCLLLLLLCQFMEDRSAQAGNCWLRQAKNGRCQVLYKTELSKEECCSTGRLSTSWTEEDVNDNTLFKWMIFNGGAPNCIPCKETCENVDCGPGKKCRMNKKNKPRCVCAPDCSNITWKGPVCGLDGKTYRNECALLKARCKEQPELEVQYQGRCKKTCRDVFCPGSSTCVVDQTNNAYCVTCNRICPEPASSEQYLCGNDGVTYSSACHLRKATCLLGRSIGLAYEGKCIKAKSCEDIQCTGGKKCLWDFKVGRGRCSLCDELCPDSKSDEPVCASDNATYASECAMKEAACSSGVLLEVKHSGSCNSISEDTEEEEEDEDQDYSFPISSILEW |
|---|---|
| Typical dose | 100–200 mcg/day subcutaneous (research use; cycles of 10–30 days on, 3–4 weeks off) |
| Half-life | ~90 minutes (recombinant injectable form); endogenous FST-315 isoform estimated ~10–15 hours |
Vendors selling Follistatin 344
| Vendor | Size | Price | Listed purity | Trust |
|---|---|---|---|---|
| Peptide Tech | 1 mg | $98.99 | — | 94 |
| Peptidology | 1 mg | $179.99 | — | 89 |
| Peptidegurus | 1 mg | — | — | 84 |
| MEI-PEPETIDE | 1 mg | $170.00 | — | 48 |
| Biotech Peptides | 1 mg | $162.00 | — | — |
| Core Peptides | 1 mg | $138.00 | — | — |
| Genetic Peptide | 1 mg | $175.00 | — | — |
| Paramount Peptides | 1 mg | $155.00 | — | — |
Research
Peptides are short chains of amino acids with a unique pharmacological niche between small-molecule drugs and large proteins. Their use in sports medicine is rapidly expanding, driven by patient demand for accelerated injury recovery and performance enhancement.
source →Therapeutic peptides are short chains of amino acids used to treat metabolic and endocrine conditions such as obesity and type 2 diabetes.
source →Myostatin (Mstn), a well-characterized member of the transforming growth factor-β (TGF-β) superfamily, serves as a key negative regulator of skeletal muscle mass. Its overactivation is closely associated with the pathogenesis of various musculoskeletal and metabolic disorders.
source →The usage of ACE-031 (Ramatercept), a dimeric fusion protein consisting of a human activin receptor IIB (ACVR2B) fragment linked to an Fc-part of human IgG1, is banned according to chapter S4.3 of the "WADA 2024 List of Prohibited Substances and Methods" due to its potential performance enhancing properties.
source →Skeletal muscle is one of the leading frameworks of the musculo-skeletal system, which works in synergy with the bones. Long skeletal muscles provide stability and mobility to the human body and are primarily composed of proteins.
source →Purpose To present 11 bodybuilding athletes who developed central serous chorioretinopathy (CSCR) following high-dose subcutaneous follistatin-344, a peptide-based performance and image enhancing drug, injections to increase muscle mass. Methods This is a retrospective case series from one institution.
source →Follistatin, a myostatin-inhibiting protein, is prohibited according to chapter S4 of the "WADA 2019 List of Prohibited Substances and Methods". While currently no approved pharmaceutical formulations of follistatin are available, follistatin can be bought on the black market.
source →We delivered plasmid DNA encoding therapeutic genes to the muscles of mouse models of limb girdle muscular dystrophy (LGMD) 2A, 2B, and 2D, deficient in calpain3, dysferlin, and alpha-sarcoglycan, respectively. We also delivered the human follistatin gene, which has the potential to increase therapeutic benefit.
source →Follistatin (FST), which was first found in the follicles of cattle and pigs, has been shown to be an essential regulator for muscle development.
source →Pharmacologic strategies have provided modest improvement in the devastating muscle-wasting disease, Duchenne muscular dystrophy (DMD).
source →Increasing the size and strength of muscles represents a promising therapeutic strategy for musculoskeletal disorders, and interest has focused on myostatin, a negative regulator of muscle growth.
source →