Follistatin 315 vs Gonadorelin
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
Follistatin 315Sexual Health & LibidoAnti-Aging & Longevity
Gonadorelin- 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.
- 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.
- Half-Life
- ~3–5 hours (longer systemic circulation vs FST-344)
- ~2–4 minutes (extremely short); pulsatile dosing required to avoid desensitization
- Admin Route
- SubQ, IM
- SubQ, Intranasal
- Research
- —
- —
- Typical Dose
- No established human dosing protocol
- 100 mcg
- Frequency
- Research use only
- Twice daily (every 12 hours)
- 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
- 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)
- 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 reactions
- Headache
- Nausea at initiation
- Tachycardia (rare)
- +1 more
- Stacks With
- —
- —