Follistatin 315 vs Pal-GHK
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
Follistatin 315Skin & CosmeticAnti-Aging & Longevity
Pal-GHK- 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.
- Pal-GHK is the palmitoylated form of the GHK tripeptide without a copper ion. By conjugating palmitic acid to glycine-histidine-lysine, skin penetration is substantially enhanced, enabling deeper dermal collagen stimulation. It is commonly paired with Pal-GHK-Cu or GHK-Cu in anti-aging formulations.
- Half-Life
- ~3–5 hours (longer systemic circulation vs FST-344)
- Extended (lipid depot in stratum corneum)
- Admin Route
- SubQ, IM
- Topical
- Research
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- Typical Dose
- No established human dosing protocol
- 0.005–0.1% in formulation
- Frequency
- Research use only
- Once or 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
- Stimulates collagen I and III synthesis in dermis
- Reduces the appearance of fine lines and wrinkles
- Improves skin elasticity and firmness
- Inhibits collagenase (MMP-1) to preserve existing collagen
- Enhances wound healing and skin repair
- Well-tolerated in anti-aging serums and creams
- 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 skin irritation at very high concentrations
- Possible formulation-dependent comedogenicity
- Stacks With
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