Gonadorelin vs Follistatin 315
Side-by-side comparison of key properties, dosing, and research.
Sexual Health & LibidoAnti-Aging & Longevity
GonadorelinAnabolic & IGF
Follistatin 315- Summary
- Gonadorelin is the synthetic form of endogenous GnRH (gonadotropin-releasing hormone). It stimulates the pituitary to release LH and FSH, maintaining testicular function and testosterone production. Widely used alongside TRT to prevent testicular atrophy and preserve fertility.
- 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.
- Half-Life
- ~2–4 minutes (extremely short); pulsatile dosing required to avoid desensitization
- ~3–5 hours (longer systemic circulation vs FST-344)
- Admin Route
- SubQ, Intranasal
- SubQ, IM
- Research
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- Typical Dose
- 100 mcg
- No established human dosing protocol
- Frequency
- Twice daily (every 12 hours)
- Research use only
- Key Benefits
- Maintains testicular size during TRT
- Preserves fertility and sperm production during testosterone use
- Stimulates endogenous LH/FSH production
- Maintains HPG axis function during exogenous hormone use
- Used for HCG-free TRT protocols
- Helps restart natural testosterone production (PCT)
- 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
- Side Effects
- Injection site reactions
- Headache
- Nausea at initiation
- Tachycardia (rare)
- +1 more
- 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
- Stacks With
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