Follistatin 315 vs KPV
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
Follistatin 315Immune SupportRecovery & Repair
KPV- 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.
- KPV is a naturally occurring anti-inflammatory tripeptide derived from the C-terminal of alpha-MSH. It powerfully suppresses intestinal and systemic inflammation via melanocortin receptors, making it valuable for IBD, gut healing, and wound repair.
- Half-Life
- ~3–5 hours (longer systemic circulation vs FST-344)
- Short half-life (~15–30 minutes), but effects persist longer due to receptor-level anti-inflammatory cascades
- Admin Route
- SubQ, IM
- Oral, SubQ, Topical
- Research
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- Typical Dose
- No established human dosing protocol
- 500 mcg – 1 mg
- Frequency
- Research use only
- Once to twice 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
- Reduces intestinal inflammation (IBD, Crohn's, colitis)
- Promotes gut mucosal healing and barrier integrity
- Accelerates wound healing topically
- Suppresses systemic inflammatory cytokines
- Antimicrobial properties against pathogens
- Reduces neuroinflammation when administered systemically
- May improve symptoms of inflammatory skin conditions
- 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
- Mild injection site reactions (SC)
- Rare: transient flushing
- Stacks With
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