Follistatin 344
Also known as: Follistatin 344, Follistatin-344, Follistatin
Follistatin 344 is the full-length precursor isoform of follistatin studied for blocking myostatin and activin to drive muscle growth and tissue repair.
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Mechanism of Action
Follistatin 344 is the full-length precursor form of follistatin that is proteolytically processed and binds members of the TGF-beta superfamily, principally myostatin (GDF-8) and activin A, with high affinity. By neutralizing myostatin it prevents activation of the activin type II receptors (ActRIIA/B) and the SMAD2/3 cascade that suppresses skeletal muscle growth. Its strong heparan-sulfate binding gives it greater retention at cell surfaces and tissues, enhancing local antagonism of myostatin and promoting satellite-cell-driven hypertrophy and repair.
- Half-life
- Short in circulation; gene-therapy delivery extends apparent duration
- Administration Routes
- subcutaneous, intramuscular
- Research Status
- Preclinical
Reported Benefits
- Potent myostatin inhibition to promote muscle hypertrophy
- May increase lean mass and strength in models
- Supports muscle repair and regeneration
- Studied for muscular dystrophy and age-related muscle loss
- Strong tissue retention via heparan-sulfate binding
Potential Side Effects
- Limited human safety data
- Theoretical reproductive and endocrine effects via activin blockade
- Possible injection-site reaction
- Concerns about unregulated tissue growth with prolonged use
Common Dosing
No validated human regimen; research-grade and animal studies use microgram-range injections or viral-vector gene delivery. For research use only; not personal medical advice.
The dosing information above is aggregated from research literature and anecdotal community reports for educational purposes only. It is not a recommendation, prescription, or medical advice. Peptides are sold as research chemicals only and are not intended for human use.
Contraindications
- Known hypersensitivity to the peptide
- Active or history of malignancy
- Pregnancy or breastfeeding
Follistatin 315
Follistatin 315 is the circulating isoform of follistatin, a myostatin-binding protein studied for promoting muscle growth by removing the brake on muscle development.
ACE-031
ACE-031 is a soluble decoy receptor (ActRIIB-Fc fusion) studied as a myostatin inhibitor to increase muscle mass and strength.
IGF-1 LR3
IGF-1 LR3 (Long R3 IGF-1) is an engineered, long-acting analog of insulin-like growth factor 1 studied for sustained anabolic and tissue-growth signaling. Its modifications give it a far longer half-life than native IGF-1.
MGF (Mechano Growth Factor)
MGF is a splice variant of IGF-1 produced locally in muscle in response to mechanical loading or damage. It is studied for its role in activating muscle stem cells and supporting tissue repair.
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A phase 1/2a follistatin gene therapy trial for becker muscular dystrophy
2015
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Follistatin gene delivery enhances muscle growth and strength in nonhuman primates
2009
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Long-term enhancement of skeletal muscle mass and strength by single gene administration of myostatin inhibitors
2008
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Central serous chorioretinopathy associated with high-dose follistatin-344: a retrospective case series
2020