Follistatin 315 vs CJC-1295
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
Follistatin 315Growth Hormone Peptides
CJC-1295- 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.
- CJC-1295 is a synthetic GHRH analog that stimulates the pituitary gland to produce and release growth hormone. The DAC (Drug Affinity Complex) version has a markedly extended half-life. The No DAC version (Modified GRF 1-29) preserves natural pulsatile GH release and is preferred in most protocols.
- Half-Life
- ~3–5 hours (longer systemic circulation vs FST-344)
- ~30 minutes (No DAC) / 6–8 days (with DAC)
- Admin Route
- SubQ, IM
- SubQ
- Research
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- Typical Dose
- No established human dosing protocol
- 100 mcg
- Frequency
- Research use only
- Once daily, before bed
- 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
- Sustained increase in growth hormone levels
- Enhanced muscle growth and strength
- Improved fat metabolism and body composition
- Better recovery and tissue repair
- Increased bone density
- Enhanced immune function
- Improved skin quality and collagen production
- Synergistic GH release when combined with GHRPs like Ipamorelin
- 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
- Water retention / puffiness
- Carpal tunnel syndrome (with prolonged use)
- Injection site irritation
- Hunger increase (minor)
- +1 more
- Stacks With
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