Follistatin 315 vs GHK-Cu
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
Follistatin 315Skin & CosmeticRecovery & RepairAnti-Aging & Longevity
GHK-Cu- 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.
- GHK-Cu is a naturally occurring copper complex that declines with age. It is one of the most studied anti-aging peptides, known for powerful skin rejuvenation, wound healing, and tissue remodeling effects.
- Half-Life
- ~3–5 hours (longer systemic circulation vs FST-344)
- 2–4 hours
- Admin Route
- SubQ, IM
- SubQ, Topical
- Research
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- Typical Dose
- No established human dosing protocol
- 1–3 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
- Reduces wrinkles and fine lines
- Improves skin firmness and elasticity
- Accelerates wound healing
- Reduces inflammation and oxidative damage
- Promotes hair growth and thickness
- Supports collagen and elastin production
- May improve overall skin health and appearance
- Resets aged fibroblast behavior
- Anti-fibrotic — reduces scar tissue formation
- 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
- Temporary blue-green discoloration at injection site (from copper — harmless)
- Post-injection sting (brief)
- Skin irritation with topical use (rare)
- Stacks With
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