Follistatin 315 vs Melanotan II
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
Follistatin 315Sexual Health & Libido
Melanotan II- 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.
- Melanotan II is a synthetic analog of alpha-melanocyte-stimulating hormone (α-MSH) that stimulates melanin production (skin tanning), suppresses appetite, and enhances sexual function. It is not FDA-approved and has significant safety concerns including mole changes and cardiovascular effects.
- Half-Life
- ~3–5 hours (longer systemic circulation vs FST-344)
- 1–2 hours
- Admin Route
- SubQ, IM
- SubQ
- Research
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- Typical Dose
- No established human dosing protocol
- 0.25–0.5 mg
- Frequency
- Research use only
- Once daily
- 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
- Promotes skin tanning and melanin production
- Reduces UV exposure needed to tan
- Enhances libido and sexual function
- May suppress appetite
- Faster, deeper tan development
- Longer-lasting tan maintenance
- Potential photoprotective effects
- 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
- Nausea (very common, especially in first days)
- Facial flushing
- Spontaneous erections in men
- Darkening or changes in existing moles (monitor closely)
- +3 more
- Stacks With
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