Follistatin 315 vs Ipamorelin
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
Follistatin 315Growth Hormone Peptides
Ipamorelin- 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.
- Ipamorelin is a selective GHRP (growth hormone releasing peptide) and one of the cleanest GH secretagogues available. It selectively stimulates GH release without significantly raising cortisol, prolactin, or appetite — making it ideal for long-term use and anti-aging protocols.
- Half-Life
- ~3–5 hours (longer systemic circulation vs FST-344)
- 2 hours
- Admin Route
- SubQ, IM
- SubQ
- Research
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- Typical Dose
- No established human dosing protocol
- 100–300 mcg
- 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
- Increases lean muscle mass
- Enhances fat loss
- Improves recovery time
- Strengthens bones and joints
- Better sleep quality and REM sleep
- Enhanced skin elasticity
- Minimal impact on hunger or cortisol
- No cortisol or prolactin spike
- Clean GH release suitable for long-term protocols
- 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
- Injection site irritation
- Temporary water retention (mild)
- Possible hunger increase (milder than GHRP-6)
- Numbness or tingling in extremities (rare)
- Stacks With
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