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Muscle & strength

Follistatin-344

Gray market

Checked · 18 sources · 6 corrections on this page · No vendors · No affiliates · No one buys a word of it

0 human trials of the protein

Preclinical · two gene-therapy trials · rodent studies of the protein

Gray market · No FDA ruling — not on any list

Sold as a research chemical. Some clinics and pharmacies still supply it; that’s their risk, not a change in the rule.

Bottom line

The genetics are nailed. What's actually in the vial is a coin flip.

Also called
FS-344 · FS-315 (splice variant) · activin-binding protein · FST
Category
Protein — Myostatin / Activin-Binding Glycoprotein
Molecular Weight
~31–39 kDa (glycosylated)
Class
TGF-β superfamily-binding glycoprotein
Isoforms
FS-315 (circulating), FS-288 (cell-bound), FS-344 (precursor)
Route (studied)
No study of it
Route (sold)
SubQ or IM vials (research chemical)
FDA Status
Not approved (Phase 1/2 gene therapy)
Primary Targets
Myostatin (GDF-8), activin A, activin B
Trials
Mendell BMD 2015, Mendell sIBM 2017
WADA Status
Prohibited (S4.3 — myostatin-binding proteins)
Gray-Market Risk
Very high — counterfeits common
Cost & Access
Research-only

Also for muscle & strength

The other four questions

What does it do? In rodents, blocking myostatin grows bigger muscles. But heart and tendon tissue grow slower than the main muscle, which is exactly where injury risk lives.
Who uses it? Bodybuilders and body-composition self-experimenters buying vials that few vendors can manufacture correctly.
Does the evidence hold up? The underlying biology is ironclad — cattle, mice, and a famous German boy in the New England Journal all prove it. But every human trial that actually worked used gene therapy, not injected follistatin from a vial. Vial follistatin has zero controlled human data.
Bottom line? The genetics are nailed. What's actually in the vial is a coin flip.

Dosing from the Literature

Published for muscle: gene-therapy doses from two trials in muscle disease, not protein from a vial. Not published: any human dose of injected follistatin.

No trial has given injected recombinant follistatin to a person. The row below is the gene-therapy dose from the two published trials, which delivered the gene, not the protein.

Route / ContextDose RangeFrequencyNotes
AAV-follistatin gene therapy (Mendell 2015, 2017)3 × 10¹¹–6 × 10¹¹ vg/kg per leg IM (quadriceps)Single injectionGene therapy, not recombinant protein. Not replicable outside a trial setting.
Dosing Disclaimer

Recombinant follistatin is not FDA-approved and no trial has given it to a person; the only published human doses are of gene therapy, in muscle disease (Mendell et al., 2015; Mendell et al., 2017). Always work with a licensed healthcare provider.

→ Calculator — vial-to-syringe math

What It Is

Follistatin (FST) is an endogenous single-chain glycoprotein, first characterized in the 1980s in ovarian follicular fluid, that acts as a high-affinity binding protein for members of the transforming growth factor-beta (TGF-β) superfamily — most notably myostatin (also known as growth differentiation factor 8, GDF-8), activin A, activin B, and several bone morphogenetic proteins. By sequestering these ligands and preventing their engagement with activin-receptor type II (ActRII) signaling, follistatin functions as the endogenous "brake release" on muscle protein synthesis, satellite cell (muscle stem cell) proliferation, and a set of related reproductive and developmental programs.

The human follistatin gene (FST) generates two principal protein isoforms by alternative splicing: follistatin-288 (FS-288), which binds heparan sulfate proteoglycans on cell surfaces, and follistatin-315 (FS-315), which circulates free in plasma. Both are processed from a larger 344-amino-acid precursor (FS-344). "Follistatin-344" as sold in the research-peptide community usually refers to the full-length precursor; "Follistatin-315" refers to the dominant circulating form. In vivo, the precursor is cleaved and FS-315 and FS-288 are the functional species; the labeling on vendor products is often inconsistent with the actual isoform content.

The biological rationale for pharmacologic follistatin comes from genetic experiments that are among the most dramatic in modern muscle biology. Myostatin knockout mice (McPherron, Lee 1997; Nature) develop 2–3× normal muscle mass. Belgian Blue and Piedmontese cattle carry naturally occurring myostatin loss-of-function mutations and display the "double-muscled" phenotype familiar from agricultural breeding. Schuelke et al. 2004 (New England Journal of Medicine; PMID 15215484) documented a single German child with homozygous myostatin loss-of-function who displayed extraordinary muscularity from birth and, at 4.5 years of age, could hold two 3-kg dumbbells in horizontal suspension with his arms extended. The pathway is unambiguously the dominant negative regulator of human muscle mass.

Translating this to therapy has been challenging. Recombinant follistatin protein is a relatively large, fragile glycoprotein that is difficult to manufacture at biological quality outside academic and industrial pharmaceutical settings, has uncharacterized plasma pharmacokinetics in humans, and carries potential immunogenicity. The clinically advanced programs have therefore pursued AAV-follistatin gene therapy — adeno-associated-virus-delivered follistatin expression cassettes — rather than recombinant protein. Mendell and colleagues at Nationwide Children's Hospital conducted Phase 1/2 AAV-follistatin trials in Becker muscular dystrophy (Mendell 2015) and sporadic inclusion body myositis (Mendell 2017), six patients each, reporting no serious safety problems and walking gains in four of six in each trial. Injectable recombinant follistatin for healthy community users occupies an entirely different category — no controlled human trial data, significant sourcing risk, and uncharacterized long-term safety.

Mechanism of Action

Follistatin's mechanism is ligand sequestration of TGF-β superfamily members, with myostatin as the central target for muscle-related effects.

  • Myostatin (GDF-8) neutralization — Follistatin binds myostatin with high affinity, preventing myostatin from engaging activin receptor type IIB (ActRIIB) on muscle cells. Normally, myostatin-ActRIIB signaling activates Smad2/3 transcription factors that inhibit muscle protein synthesis and satellite cell activation. Blocking this signaling is the principal mechanism behind the hypertrophy phenotype.
  • Activin A and activin B neutralization — Follistatin also binds activins, which signal through overlapping ActRII receptors and contribute to muscle-growth inhibition. Activin A additionally plays roles in reproduction (FSH regulation), hematopoiesis, and wound healing. Broader activin neutralization by FS-344 / FS-315 has been associated with reproductive and hematologic effects in preclinical models.
  • Satellite cell activation — With myostatin inhibition, myogenic satellite cells proliferate and fuse more readily, supporting both muscle fiber hypertrophy (existing fiber growth) and, in animal models, hyperplasia (new fiber formation). Hyperplasia is rarely documented in humans.
  • FS-315 vs FS-288 vs FS-344 distinction — FS-315 circulates as the dominant plasma form and has the broadest systemic activin- and myostatin-binding activity. FS-288 binds to heparan sulfate proteoglycans on muscle-cell surfaces, providing localized, muscle-biased myostatin neutralization with less systemic activin impact. FS-344 is the full-length precursor, processed in vivo. Community-marketed "FS-315 vs FS-344" distinctions are often more marketing than biology, since FS-344 is cleaved to the other isoforms upon exposure to physiologic proteases.
  • Downstream signaling — With ActRII signaling relieved, the ubiquitin-proteasome muscle-proteolysis program (MuRF-1, atrogin-1) is downregulated, mTOR (the cell's master switch for growth and protein-building)/Akt protein-synthesis signaling is indirectly facilitated, and satellite-cell MyoD/myogenin pathways are activated.
  • Other TGF-β ligands — Follistatin binds several BMPs (BMP-2, BMP-6, BMP-7) with lower affinity than myostatin/activin. These interactions may contribute to bone and developmental effects.
  • Cardiac and tendon tissue — The rodent cardiac evidence does not run one way: aged myostatin-knockout mice had preserved cardiac function, with better fractional shortening than wild-type mice (Morissette et al., 2009), while in mice whose hearts were pressure-loaded surgically, an anti-myostatin antibody grew skeletal muscle and grip strength but did not reduce cardiac hypertrophy or fibrosis (Shi et al., 2023). No study read for this page measured tendon or connective-tissue growth under myostatin blockade.
  • Reproductive axis — Activin neutralization suppresses FSH secretion in the anterior pituitary (activin normally stimulates FSH). FS-344 with broader activin-binding activity is more likely to impact reproductive hormones than FS-288 with its localized muscle-surface action.
  • What follistatin does not do — Does not directly stimulate muscle protein synthesis (it releases an inhibitor, rather than acting as a growth-signal agonist). Does not engage androgen, growth hormone, or IGF-1 signaling directly. Does not cross the blood-brain barrier meaningfully.

What the Research Shows

The follistatin / myostatin pathway is one of the best-validated muscle-biology targets. The evidence for exogenous follistatin as a therapeutic is much thinner, split across genetic validation, AAV gene therapy, and the essentially unvalidated recombinant-protein approach.

  • Myostatin knockout mice (McPherron, Lee, Lee 1997; Nature) — Seminal demonstration of the pathway. Myostatin-null mice (Mstn−/−) display 2–3× normal muscle mass. The "double-muscle" phenotype.
  • Belgian Blue and Piedmontese cattle — Naturally occurring myostatin-inactivating mutations. Classical double-muscle phenotype; an established farming example of the pathway.
  • Schuelke et al. 2004 (NEJM; PMID 15215484) — Human case report of a child with homozygous myostatin loss-of-function showing extraordinary muscularity and strength. Gold-standard evidence that the pathway translates to humans. The authors reported no health problems by age 4.5, and noted he was still too young for heart problems to be ruled out.
  • Lee & McPherron 2001 (PNAS; PMID 11459935) — Regulation of myostatin activity and muscle growth via follistatin and related inhibitors. Established the pharmacologic rationale for follistatin-based myostatin inhibition.
  • AAV-follistatin in Becker muscular dystrophy (Mendell et al. 2015, Mol Ther; PMID 25322757) — Phase 1/2a AAV1-FS344 gene therapy trial at Nationwide Children's Hospital. Six patients received AAV1.CMV.FS344 into both quadriceps, three at 3 × 10¹¹ and three at 6 × 10¹¹ vg/kg per leg. On the 6-minute walk test, four of six improved (by 29 to 125 m) and two showed no change; no adverse effects were reported.
  • AAV-follistatin in sporadic inclusion body myositis (Mendell et al. 2017, Mol Ther; PMID 28279643) — The same AAV1-FS344 approach, 6 × 10¹¹ vg/kg into both quadriceps, in six patients, with an exercise regimen. The 6-minute walk improved by a median 56 m a year in treated patients against a decline of 25.8 m a year in eight untreated, matched patients (p = 0.01); four of six gained 58 to 153 m.
  • Review of the BMD program (Al-Zaidy et al. 2015, J Neuromuscul Dis; PMID 27858738) — Reviews the case for follistatin gene therapy and the results of the Becker muscular dystrophy trial above. A review, not a separate trial.
  • Body composition in animal models — Exogenous follistatin administration in rodents produces dose-dependent lean mass gain and fat mass reduction.
  • ActRIIB-Fc and myostatin antibodies (related class) — Programs targeting the pathway with a soluble ActRIIB decoy receptor (ACE-031; Attie et al., 2013), an antibody against the activin type II receptors (bimagrumab) or antibodies against myostatin (domagrozumab, landogrozumab, stamulumab) have advanced further clinically than recombinant follistatin protein, with mixed Phase 2/3 outcomes — muscle mass gains reliably achieved; functional outcomes in dystrophies and aging have been less robust.
  • Injectable recombinant follistatin in humans — Essentially no controlled human trial data. Any efficacy claim from community-sourced injectable follistatin rests entirely on anecdote.
Research Limitations — Strong Pathway Biology, Weak Protein-Drug Evidence

The myostatin / follistatin pathway is genetically and pharmacologically validated at the highest standard of evidence (knockout models, natural human mutations, multiple independent convergent pharmacologic programs). The case for injectable recombinant follistatin specifically is dramatically weaker — no controlled human trial, severe manufacturing complexity, uncharacterized pharmacokinetics, immunogenicity concerns, and widely variable research-peptide product quality. Gene-therapy programs are more advanced clinically than protein-injection approaches. Community-sourced injectable follistatin is not the compound that worked in the Mendell trials: those used AAV-delivered gene therapy, not recombinant protein.

Human Data

  • Schuelke 2004 (NEJM) — single-case myostatin-null human — The only well-documented human case of inherited myostatin deficiency. Extraordinary muscularity; no health problems reported by age 4.5.
  • Mendell 2015 — AAV-follistatin Phase 1/2a in Becker muscular dystrophy — AAV1-FS344 intramuscular gene therapy; 6 BMD patients at two doses. Four of six walked farther on the 6-minute walk test (29 to 125 m); no adverse effects reported.
  • Mendell 2017 — AAV-follistatin in sporadic inclusion body myositis — Same AAV1-FS344 approach; 6 patients, with exercise. Median +56 m a year on the 6-minute walk test against −25.8 m a year in 8 untreated, matched patients.
  • Al-Zaidy 2015 — review — Reviews follistatin gene therapy and the Becker trial results; not a separate trial.
  • Nationwide Children's gene therapy program — Broader follistatin gene-therapy research base led by Brian Kaspar, Jerry Mendell, and colleagues. Has since pivoted some resources to other dystrophy targets.
  • ActRIIB / anti-myostatin class trials (comparators, not follistatin) — Multiple sponsor programs (Novartis bimagrumab, Pfizer domagrozumab, Lilly landogrozumab, Wyeth stamulumab) tested myostatin-axis blockade in Duchenne muscular dystrophy, sporadic inclusion body myositis, hip fracture recovery, and sarcopenia. Muscle growth generally achieved; clinical endpoints less reliably met. Provides class-relevant safety and efficacy context.
  • No controlled injectable-protein trials — No published RCT of recombinant follistatin protein in healthy humans or in any clinical indication.

Reconstitution & Storage

No label or guideline gives a storage condition or shelf life for recombinant follistatin; it is sold as a research chemical. The table is arithmetic only: what a vial of a given size holds once dissolved (U-100 insulin syringe: 100 units = 1 mL). It is not a recommendation.

Vial SizeBAC WaterConcentration
1 mg1 mL1 mg/mL
1 mg2 mL0.5 mg/mL
5 mg5 mL1 mg/mL

→ Calculator — vial-to-syringe math

Side Effects & Risks

Important

Follistatin is a fragile glycoprotein few vendors manufacture correctly. WADA bans it under S4.3. The rodent cardiac evidence is mixed, no human cardiac or immunogenicity data for injectable follistatin exist, and the class’s cancer concerns are theoretical.

The follistatin / myostatin-inhibition class has theoretical and (from class programs) documented concerns.

  • Immunogenicity — As a large glycoprotein, recombinant follistatin can trigger anti-drug antibody formation. Antibodies may neutralize efficacy over time and could, in rare cases, cross-react with endogenous follistatin — the most concerning theoretical scenario because endogenous follistatin has broad physiologic roles. No systematic human immunogenicity data for injectable follistatin exists.
  • Cardiac remodeling — What rodent studies show is mixed (see What the Research Shows), and no cardiac outcome data for injectable follistatin in people exist.
  • Tendon and connective tissue — No study read for this page measured how tendons respond to myostatin blockade, and no case report of tendon rupture under it is cited here.
  • Reproductive effects — Activin A plays a central role in pituitary FSH regulation. FS-344's broader activin-binding activity can (theoretically and in preclinical models) alter FSH, LH, and downstream reproductive hormone signaling. FS-315 with narrower activity has less documented reproductive impact.
  • Hematologic effects — Activin A is involved in erythropoiesis and hematopoietic stem-cell maintenance. Chronic broad activin inhibition could theoretically affect blood cell production. Limited human data.
  • Muscle growth overshoot — Unchecked hypertrophy can produce cosmetic asymmetry, muscular imbalance, and postural strain if the pharmacology interacts poorly with the training stimulus.
  • Metabolic effects — Acute muscle anabolism can increase caloric requirements, alter insulin sensitivity, and in some community reports produce hypoglycemic tendencies.
  • Long-term safety unknown — Zero long-term human safety data for injectable follistatin. The AAV gene-therapy trials have the longest-duration follistatin-expression follow-up but are a different therapeutic modality.
  • Sourcing / counterfeit risk (the dominant practical concern) — Follistatin is a complex glycoprotein that is difficult and expensive to manufacture at biologically active quality. Research-chemical vendors sell material of widely varying purity, folding, and true-protein content. Analytical verification (HPLC-MS plus, ideally, cell-based bioassay confirming myostatin-binding activity) is essentially absent in the community market.
  • WADA prohibited — Follistatin and myostatin inhibitors are prohibited at all times under S4.3 (hormone and metabolic modulators: agents preventing activin receptor IIB activation — "Myostatin-binding proteins (e.g. follistatin, myostatin propeptide)"). Detection methods evolving.
  • Cancer concern — Myostatin signaling has tumor-suppressive functions in some tissues. Chronic broad inhibition could theoretically promote growth of occult malignancies. Absolute contraindication in any history of cancer or precancerous lesion.
  • Pregnancy and reproductive-age women — Contraindicated. Follistatin's role in reproductive biology is broader than muscle.
  • Pediatric use — Not appropriate. Growth-plate effects and developmental consequences unknown.

Bloodwork & Monitoring

No trial, label or guideline sets monitoring for injected follistatin, and no trial has given it to a person. The gene-therapy trials followed muscle strength and function, and took muscle biopsies (Mendell et al., 2015; Mendell et al., 2017).

Commonly Stacked With

No published study has combined injected follistatin with another compound.

Stacking this? Read the receipt →

→ Calculator — vial-to-syringe math

Legal Status

Current Status — April 2026

Recombinant follistatin-344 and follistatin-315 are not FDA-approved for any indication. Clinical development in the follistatin space is concentrated in AAV-follistatin gene therapy programs (Nationwide Children's Hospital and related academic centers), not in recombinant-protein injectable formulations. The AAV-follistatin IBM and BMD gene-therapy trials have not resulted in FDA approval as of April 2026; the modality is distinct from injectable protein.

Follistatin is not on the FDA Category 2 Bulk Drug Substances peptide list, and it was not among the 12 peptides FDA removed from that list in April 2026 (FDA 503A categories list, April 22, 2026). Those removals concerned smaller peptides (BPC-157, injectable GHK-Cu, KPV and others) where 503A/503B compounding is commercially viable. Follistatin's glycoprotein complexity makes practical 503A compounding uncommercial regardless of regulatory posture.

WADA: Follistatin and myostatin inhibitors are explicitly prohibited at all times under S4.3 (hormone and metabolic modulators: agents preventing activin receptor IIB activation, which names follistatin among the myostatin-binding proteins). Detection methodology continues to evolve. Any tested athlete using follistatin faces sanction.

As a non-approved, non-compounded biologic sold through research-chemical channels, follistatin exists in a regulatory gray area for personal use. Bulk import, commercial resale, and import claiming human-use intent are subject to FDA and customs action.

Cost & Access

Follistatin-344 and follistatin-315 are available only through research-chemical vendors for laboratory research purposes. Product quality varies dramatically; complex glycoproteins require substantial manufacturing infrastructure to produce at biologically active purity, and much of the research-chemical market material is likely degraded, misfolded, or counterfeit. Third-party COA documentation (HPLC-MS plus cell-based bioassay) is the minimum verification standard; the practical gap between vendor-supplied COAs and independent analytical confirmation is wide in this space.

U.S. compounding pharmacies cannot legally compound follistatin under current FDA bulk-substance rules. The complexity of the glycoprotein effectively precludes 503A-scale compounding regardless of regulation. AAV-follistatin gene therapy (an entirely different modality) is accessible only through academic clinical trials; it is not a commercial product.

Follistatin was not among the 12 peptides FDA removed from Category 2 in April 2026 (FDA 503A categories list, April 22, 2026). Absent a sponsor advancing recombinant follistatin protein through the BLA pathway, the research-only status will persist. The AAV-follistatin gene therapy space may advance to approval for specific dystrophies on a multi-year timeline; this will not provide general access to injectable follistatin for community use.

Estimated pricing as of April 2026. Actual costs vary by provider, location, and prescription status. Kalios does not sell compounds.

References

  1. McPherron AC, Lawler AM, Lee SJ. Regulation of skeletal muscle mass in mice by a new TGF-β superfamily member. Nature. 1997;387(6628):83-90. PMID: 9139826. (Myostatin discovery and knockout mouse phenotype.)
  2. Lee SJ, McPherron AC. Regulation of myostatin activity and muscle growth. Proc Natl Acad Sci USA. 2001;98(16):9306-9311. PMID: 11459935.
  3. Schuelke M, Wagner KR, Stolz LE, Hübner C, Riebel T, Kömen W, Braun T, Tobin JF, Lee SJ. Myostatin mutation associated with gross muscle hypertrophy in a child. N Engl J Med. 2004;350(26):2682-2688. PMID: 15215484. (Human case of myostatin loss-of-function.)
  4. Morissette MR, Stricker JC, Rosenberg MA, Buranasombati C, Levitan EB, Mittleman MA, Rosenzweig A. Effects of myostatin deletion in aging mice. Aging Cell. 2009;8(5):573-583. doi:10.1111/j.1474-9726.2009.00508.x. PMID: 19663901.
  5. Shi C, Zijlstra SN, de Wit S, Meijers WC, Aboumsallem JP, Silljé HHW, de Boer RA. Divergent effects of myostatin inhibition on cardiac and skeletal muscles in a mouse model of pressure overload. Am J Physiol Heart Circ Physiol. 2023;325(1):H195-H201. doi:10.1152/ajpheart.00223.2023. PMID: 37294894.
  6. Mendell JR, Sahenk Z, Malik V, Gomez AM, Flanigan KM, Lowes LP, Alfano LN, Berry K, Meadows E, Lewis S, Braun L, Shontz K, Rouhana M, Clark KR, Rosales XQ, Al-Zaidy S, Govoni A, Rodino-Klapac LR, Hogan MJ, Kaspar BK. A phase 1/2a follistatin gene therapy trial for becker muscular dystrophy. Mol Ther. 2015;23(1):192-201. PMID: 25322757. (AAV1-FS344 trial in BMD.)
  7. Mendell JR, Sahenk Z, Al-Zaidy S, Rodino-Klapac LR, Lowes LP, Alfano LN, Berry K, Miller N, Yalvac M, Dvorchik I, Moore-Clingenpeel M, Flanigan KM, Church K, Shontz K, Curry C, Lewis S, McColly M, Hogan MJ, Kaspar BK. Follistatin gene therapy for sporadic inclusion body myositis improves functional outcomes. Mol Ther. 2017;25(4):870-879. PMID: 28279643. (AAV1-FS344 trial in sporadic inclusion body myositis.)
  8. Rodino-Klapac LR, Haidet AM, Kota J, Handy C, Kaspar BK, Mendell JR. Inhibition of myostatin with emphasis on follistatin as a therapy for muscle disease. Muscle Nerve. 2009;39(3):283-296. PMID: 19208403. (Mechanistic review.)
  9. Kota J, Handy CR, Haidet AM, Montgomery CL, Eagle A, Rodino-Klapac LR, Tucker D, Shilling CJ, Therlfall WR, Walker CM, Weisbrode SE, Janssen PM, Clark KR, Sahenk Z, Mendell JR, Kaspar BK. Follistatin gene delivery enhances muscle growth and strength in nonhuman primates. Sci Transl Med. 2009;1(6):6ra15. PMID: 20368179.
  10. Haidet AM, Rizo L, Handy C, Umapathi P, Eagle A, Shilling C, Boue D, Martin PT, Sahenk Z, Mendell JR, Kaspar BK. Long-term enhancement of skeletal muscle mass and strength by single gene administration of myostatin inhibitors. Proc Natl Acad Sci USA. 2008;105(11):4318-4322. PMID: 18334646.
  11. Al-Zaidy SA, Sahenk Z, Rodino-Klapac LR, Kaspar B, Mendell JR. Follistatin Gene Therapy Improves Ambulation in Becker Muscular Dystrophy. J Neuromuscul Dis. 2015;2(3):185-192. PMID: 27858738.
  12. Lee SJ. Extracellular Regulation of Myostatin: A Molecular Rheostat for Muscle Mass. Immunol Endocr Metab Agents Med Chem. 2010;10(4):183-194. PMID: 21423813. (Review of endogenous myostatin regulation including follistatin.)
  13. Thompson TB, Lerch TF, Cook RW, Woodruff TK, Jardetzky TS. The structure of the follistatin:activin complex reveals antagonism of both type I and type II receptor binding. Dev Cell. 2005;9(4):535-543. PMID: 16198295. (Structural biology of follistatin-ligand binding.)
  14. Amthor H, Nicholas G, McKinnell I, Kemp CF, Sharma M, Kambadur R, Patel K. Follistatin complexes myostatin and antagonises myostatin-mediated inhibition of myogenesis. Dev Biol. 2004;270(1):19-30. PMID: 15136138.
  15. Wagner KR, Fleckenstein JL, Amato AA, Barohn RJ, Bushby K, Escolar DM, Flanigan KM, Pestronk A, Tawil R, Wolfe GI, Eagle M, Florence JM, King WM, Pandya S, Straub V, Juneau P, Meyers K, Csimma C, Araujo T, Allen R, Parsons SA, Wozney JM, Lavallie ER, Mendell JR. A phase I/IItrial of MYO-029 in adult subjects with muscular dystrophy. Ann Neurol. 2008;63(5):561-571. PMID: 18335515. (Class-reference myostatin antibody program.)
  16. Attie KM, Borgstein NG, Yang Y, Condon CH, Wilson DM, Pearsall AE, Kumar R, Willins DA, Seehra JS, Sherman ML. A single ascending-dose study of muscle regulator ACE-031 in healthy volunteers. Muscle Nerve. 2013;47(3):416-423. PMID: 23169607. (Soluble ActRIIB approach.)
  17. WADA Prohibited List 2026. World Anti-Doping Agency. wada-ama.org. (S4.3 — myostatin-binding proteins, e.g. follistatin.)
  18. FDA. Bulk Drug Substances Nominated for Use in Compounding — 503A and 503B Categories. FDA.gov. Updated 2025–2026.

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Checked 18 Oct 2026