Follistatin 344 vs Hexarelin
A neutral, side-by-side comparison of two performance & growth hormone peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.
Follistatin 344
Follistatin 344 is a 344-amino acid isoform of follistatin — an endogenous glycoprotein that functions primarily as a myostatin and activin inhibitor. Myostatin (GDF-8) is the body's primary muscle growth suppressor; follistatin binds and neutralizes it with high affinity, removing this brake on muscle protein synthesis. Research and animal data show dramatic increases in muscle fiber size and strength when follistatin is elevated or myostatin is inhibited.
Full profileHexarelin
Hexarelin is a potent synthetic hexapeptide GHRP (Growth Hormone-Releasing Peptide) that stimulates GH release via the ghrelin receptor. It produces among the highest GH pulses of any GHRP, but also elevates cortisol and prolactin — a trade-off that distinguishes it from more selective options like Ipamorelin.
Full profile| Follistatin 344 | Hexarelin | |
|---|---|---|
| Category | Performance & Growth Hormone | Performance & Growth Hormone |
| Also known as | FST-344, Follistatin isoform 344, FST | Examorelin, EP 23905, MF-6003 |
| Evidence | Research-stage | Preclinical only |
| Dosing range | 50mcg–200mcg mcg, Once daily or every other day for 10–30 day cycles | 50mcg–200mcg mcg, 1–3x daily (cycling recommended to prevent desensitization) |
| Administration | Subcutaneous injection, Intramuscular injection (into target muscle — local effect hypothesis) | Subcutaneous injection, Intramuscular injection |
| Key side effects | Potential FSH suppression (reproductive effects in females — may affect menstrual cycle), Accelerated hair follicle cycling (Wnt pathway involvement — theoretical hair loss concern at high doses), Joint discomfort with rapid muscle tissue growth, Limited long-term human safety data | Cortisol elevation, Prolactin elevation, Water retention, Increased appetite |
| Cited sources | 3 references | 1 reference |
Key differences
- Evidence level differs: Follistatin 344 is research-stage, while Hexarelin is preclinical only.
- Administration: Follistatin 344 — Subcutaneous injection, Intramuscular injection (into target muscle — local effect hypothesis); Hexarelin — Subcutaneous injection, Intramuscular injection.
- Frequency: Follistatin 344 is typically Once daily or every other day for 10–30 day cycles; Hexarelin is 1–3x daily (cycling recommended to prevent desensitization).
- Research depth: this profile cites 3 sources for Follistatin 344 vs 1 for Hexarelin.
How each works
Follistatin 344
Follistatin's muscle effects were dramatically illustrated when mice and cattle with follistatin overexpression or myostatin knockouts developed 2–3x normal muscle mass. Human follistatin gene therapy trials (AAV-mediated) are ongoing for Becker Muscular Dystrophy, showing sustained myostatin inhibition and improved muscle function over years from a single injection. Follistatin also inhibits activin A and B (involved in muscle wasting during illness), FSH secretion (reproductive effects), and inflammatory cytokines. The 344 isoform has an extended heparin-binding domain that increases tissue retention compared to the shorter FST-288 isoform.
Hexarelin
Hexarelin produces dose-dependent GH release significantly greater than GHRP-6 or Ipamorelin. It also has direct cardioprotective effects via CD36 receptor binding, independent of GH — making it unique among GHRPs. Studies show protection from ischemic cardiac injury and myocardial fibrosis reduction in animal models. Desensitization occurs with chronic continuous use.
This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.