Follistatin 315 vs Eloralintide
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
Follistatin 315GLP-1 / Weight Loss Agonists
Eloralintide- 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.
- Eloralintide is a long-acting amylin analog under development by OPKO Health. Amylin is co-secreted with insulin and regulates post-meal glucose by slowing gastric emptying, suppressing glucagon, and promoting satiety. Eloralintide is designed for once-weekly dosing, differentiating it from the short-acting pramlintide (Symlin). It is being studied for obesity and type 2 diabetes as a complement to GLP-1 based therapies.
- Half-Life
- ~3–5 hours (longer systemic circulation vs FST-344)
- ~7 days (estimated, long-acting design)
- Admin Route
- SubQ, IM
- SubQ
- Research
- —
- —
- Typical Dose
- No established human dosing protocol
- Under investigation in Phase 1/2 trials
- 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
- Once-weekly dosing (vs multiple daily injections for pramlintide)
- Appetite suppression via central amylin receptor activation
- Reduction in post-meal glucagon secretion
- Complementary mechanism to GLP-1 agonists for combination therapy
- Slows gastric emptying for prolonged satiety
- Potential additive weight loss when combined with GLP-1 agents
- 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
- Vomiting
- Decreased appetite
- Injection site reactions
- +1 more
- Stacks With
- —
- —