Follistatin 315 vs MOTS-c
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
Follistatin 315Anti-Aging & Longevity
MOTS-c- Summary
- Follistatin 315 is a splice variant isoform of follistatin produced by alternative mRNA processing. Unlike Follistatin 344 which is tethered to cell surfaces via heparan sulfate proteoglycans, FST-315 circulates freely in the bloodstream and has broader systemic distribution. It is the predominant circulating form and exerts systemic myostatin inhibition as well as FSH suppression, making it relevant to both muscle growth and reproductive endocrinology.
- MOTS-c is a mitochondria-derived peptide (MDP) encoded within the mitochondrial genome. It acts as a metabolic regulator, improving insulin sensitivity, enhancing exercise capacity, and counteracting age-related metabolic decline. It is often called a 'mitochondrial hormone.'
- Half-Life
- ~3–5 hours (longer systemic circulation vs FST-344)
- Estimated 1–2 hours
- Admin Route
- SubQ, IM
- SubQ
- Research
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- Typical Dose
- No established human dosing protocol
- 5–15 mg
- Frequency
- Research use only
- 3–5 times per week
- Key Benefits
- Systemic myostatin inhibition for whole-body muscle growth
- Freely circulating — broader tissue distribution than FST-344
- Strong FSH-suppressive activity useful in certain hormonal protocols
- Potential for greater anabolic effect across multiple muscle groups simultaneously
- May be more relevant to reproductive endocrinology applications
- Studied in gene therapy approaches for muscular dystrophy
- Improves insulin sensitivity and glucose metabolism
- Enhances exercise capacity and endurance
- Reduces age-related metabolic decline
- Activates AMPK — the master metabolic regulator
- Promotes fat oxidation
- Anti-inflammatory effects
- May extend healthspan via mitochondrial optimization
- Increases energy and reduces fatigue
- Side Effects
- Systemic FSH suppression — significant concern for fertility
- Greater potential for off-target effects vs FST-344 due to systemic distribution
- Limited human safety data
- Potential cardiac hypertrophy with prolonged high-dose exposure
- Injection site irritation
- Fatigue during initial adaptation
- Unknown long-term profile (limited human data)
- Stacks With
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