Follistatin 344

Key Benefits#

• Inhibits myostatin — removes muscle growth ceiling
• Significant increases in muscle mass and strength
• Reduces fat mass
• Promotes bone density
• May stimulate hair follicle cycling
• Anti-fibrotic effects in muscle tissue
• Synergistic with IGF-1 and other anabolic peptides

Mechanism of Action#

Follistatin 344 works primarily by binding and neutralizing myostatin (GDF-8), a TGF-beta family member that limits muscle growth by inhibiting satellite cell activation and muscle protein synthesis. It also inhibits activin A and B, further disinhibiting muscle growth pathways. Animals with knocked-out myostatin genes develop dramatically larger muscles — follistatin mimics this effect pharmacologically. It may also promote bone density and hair follicle cycling.

Dosing Protocols#

Side Effects#

• Muscle soreness (from rapid hypertrophy)
• Potential reproductive effects (activin inhibition)
• Unknown long-term safety profile
• Possible esophageal effects at high doses (animal data)

Contraindications#

Pregnancy or planning pregnancy (activin plays a key role in reproduction). Active cancer. Experimental compound — limited human safety data.

Storage#

Lyophilized powder: store at −20°C. Reconstituted: refrigerate at 2–8°C, use within 14 days.

Featured In Stacks#

1. 1.
   Relationship Between High Serum Levels of Follistatin with Impaired Physical Function, and Severe Disease Activity in Rheumatoid Arthritis

   Gonzalez-Ponce F, Gamez-Nava JI, Jacobo-Cuevas H, Ponce-Guarneros JM, Valdivia-Tangarife ER, Nava-Valdivia CA et al. · International journal of molecular sciences · 2025PubMed Verified

2. 2.
   Detection of black market follistatin 344

   Reichel C, Gmeiner G, Thevis M · Drug testing and analysis · 2020PubMed Verified

3. 3.
   Central serous chorioretinopathy associated with high-dose follistatin-344: a retrospective case series

   Dağ U, Çağlayan M, Öncül H, Alakuş MF · International ophthalmology · 2020PubMed Verified

4. 4.
   Detection of black market follistatin 344

   Reichel C, Gmeiner G, Thevis M · Drug testing and analysis · 2019PubMed Verified

5. 5.
   The transgenic expression of human follistatin-344 increases skeletal muscle mass in pigs

   Chang F, Fang R, Wang M, Zhao X, Chang W, Zhang Z et al. · Transgenic research · 2017PubMed Verified

6. 6.
   An engineered human follistatin variant: insights into the pharmacokinetic and pharmocodynamic relationships of a novel molecule with broad therapeutic potential

   Datta-Mannan A, Yaden B, Krishnan V, Jones BE, Croy JE · The Journal of pharmacology and experimental therapeutics · 2013PubMed Verified

7. 7.
   The effects of transforming growth factor-β2 on the expression of follistatin and activin A in normal and glaucomatous human trabecular meshwork cells and tissues

   Fitzgerald AM, Benz C, Clark AF, Wordinger RJ · Investigative ophthalmology & visual science · 2012PubMed Verified

8. 8.
   SNP analysis of follistatin gene associated with polycystic ovarian syndrome

   Panneerselvam P, Sivakumari K, Jayaprakash P, Srikanth R · Advances and applications in bioinformatics and chemistry : AABC · 2010PubMed Verified

9. 9.
   Molecular cloning of cDNA for equine follistatin and its gene expression in the reproductive tissues of the mare

   Sugawara Y, Yamanouchi K, Naito K, Tachi C, Tojo H, Sawasaki T · The Journal of veterinary medical science · 1999PubMed Verified

10. 10.
    Production of follistatin in porcine endothelial cells: differential regulation by bacterial compounds and the synthetic glucocorticoid RU 28362

    Michel U, Schneider O, Kirchhof C, Meisel S, Smirnov A, Wiltfang J et al. · Endocrinology · 1996PubMed Verified

11. 11.
    Repression of glycoprotein hormone alpha-subunit gene expression and secretion by activin in alpha T3-1 cells

    Attardi B, Klatt B, Little G · Molecular endocrinology (Baltimore, Md.) · 1995PubMed Verified

12. 12.
    Isolation and characterization of bovine follistatin cDNA

    Saleh M, Garcia S, Mercer JE, Findlay JK · Journal of molecular endocrinology · 1994PubMed Verified

13. 13.
    Activin-binding protein follistatin messenger ribonucleic acid and secreted protein levels are induced by chorionic gonadotropin in cultured human granulosa-luteal cells

    Tuuri T, Erämaa M, Hildén K, Ritvos O · Endocrinology · 1994PubMed Verified

14. 14.
    Follistatin steady state messenger ribonucleic acid levels in confluent cultures of a rat renal mesangial cell line are regulated by multiple factors

    Michel U, Farnworth P · Endocrinology · 1992PubMed Verified

15. 15.
    Rat follistatin: ontogeny of steady-state mRNA levels in different tissues predicts organ-specific functions

    Michel U, Rao A, Findlay JK · Biochemical and biophysical research communications · 1991PubMed Verified

16. 16.
    Rat follistatin: gonadal and extragonadal expression and evidence for alternative splicing

    Michel U, Albiston A, Findlay JK · Biochemical and biophysical research communications · 1990PubMed Verified

17. 17.
    Intragonadal regulation of follicular maturation

    Tonetta SA, diZerega GS · Endocrine reviews · 1989ReviewPubMed Verified

18. 18.
    Primary structure of the human follistatin precursor and its genomic organization

    Shimasaki S, Koga M, Esch F, Cooksey K, Mercado M, Koba A et al. · Proceedings of the National Academy of Sciences of the United States of America · 1988PubMed Verified

19. 19.
    Porcine follistatin gene structure supports two forms of mature follistatin produced by alternative splicing

    Shimasaki S, Koga M, Esch F, Mercado M, Cooksey K, Koba A et al. · Biochemical and biophysical research communications · 1988PubMed Verified

20. 20.
    Structural characterization of follistatin: a novel follicle-stimulating hormone release-inhibiting polypeptide from the gonad

    Esch FS, Shimasaki S, Mercado M, Cooksey K, Ling N, Ying S et al. · Molecular endocrinology (Baltimore, Md.) · 1987PubMed Verified