Follistatin 315 vs Decapeptide-12
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
Follistatin 315Skin & Cosmetic
Decapeptide-12- 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.
- Decapeptide-12 is a synthetic 10-amino acid peptide developed for skin brightening and depigmentation. It selectively inhibits tyrosinase activity and downstream melanogenesis pathways, reducing hyperpigmentation, dark spots, and uneven skin tone without the irritation associated with hydroquinone.
- Half-Life
- ~3–5 hours (longer systemic circulation vs FST-344)
- Not applicable (topical)
- Admin Route
- SubQ, IM
- Topical
- Research
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- Typical Dose
- No established human dosing protocol
- 5 ppm (0.0005%) concentration
- Frequency
- Research use only
- Twice daily (AM and PM)
- 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
- Reduces hyperpigmentation and dark spots
- Evens skin tone and improves radiance
- Inhibits post-inflammatory hyperpigmentation
- Well-tolerated alternative to hydroquinone
- Effective for melasma and age spots
- Non-cytotoxic to melanocytes
- 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
- Generally very well-tolerated
- Rare mild irritation or sensitivity in some skin types
- Results may take several weeks to become visible
- Stacks With
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