Follistatin 315 vs Enclomiphene
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
Follistatin 315GLP-1 / Weight Loss Agonists
Enclomiphene- 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.
- Enclomiphene is the trans-isomer of clomiphene citrate, a selective estrogen receptor modulator (SERM) that stimulates endogenous testosterone production by blocking estrogen negative feedback on the hypothalamus and pituitary. Unlike TRT, it restores testosterone while preserving or increasing sperm production and testicular volume.
- Half-Life
- ~3–5 hours (longer systemic circulation vs FST-344)
- 5-7 days (long half-life; accumulates)
- Admin Route
- SubQ, IM
- Oral
- Research
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- Typical Dose
- No established human dosing protocol
- 12.5-25 mg per day
- Frequency
- Research use only
- Once daily or every other day
- 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
- Restores testosterone to normal range without exogenous androgen administration
- Preserves or increases sperm production and fertility
- Maintains testicular volume (unlike TRT which causes testicular atrophy)
- LH and FSH levels rise, indicating intact HPG axis function
- Option for hypogonadal men desiring fertility
- Oral administration (no injection required)
- 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
- Visual disturbances (rare but class-related SERM effect)
- Mood changes or irritability
- Hot flashes
- Elevated estradiol in some users
- +2 more
- Stacks With
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