Follistatin 315 vs Cagrilintide
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
Follistatin 315GLP-1 / Weight Loss Agonists
Cagrilintide- 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.
- Cagrilintide is a long-acting amylin analog developed by Novo Nordisk. Amylin is a peptide hormone co-secreted with insulin from pancreatic beta cells. Cagrilintide slows gastric emptying, suppresses glucagon, and reduces appetite via central amylin receptors. In combination with semaglutide (CagriSema), Phase 2 trials achieved approximately 15% body weight reduction. Phase 3 trials (REDEFINE program) are ongoing.
- Half-Life
- ~3–5 hours (longer systemic circulation vs FST-344)
- ~7–10 days
- Admin Route
- SubQ, IM
- SubQ
- Research
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- Typical Dose
- No established human dosing protocol
- 0.16 mg → 0.3 mg → 0.6 mg → 1.2 mg → 2.4 mg
- Frequency
- Research use only
- Once weekly
- 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
- ~15% body weight reduction in combination with semaglutide (CagriSema Phase 2)
- Synergistic appetite suppression complementing GLP-1 receptor agonists
- Reduces post-meal glucagon excursions improving glycemic control
- Slows gastric emptying contributing to prolonged satiety
- Once-weekly dosing via subcutaneous injection
- Potential for greater weight loss than semaglutide monotherapy
- 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
- Nausea (most common, especially during titration)
- Vomiting
- Decreased appetite
- Diarrhea
- +2 more
- Stacks With
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