Follistatin 315 vs Orforglipron
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
Follistatin 315GLP-1 / Weight Loss Agonists
Orforglipron- 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.
- Orforglipron is an oral, once-daily small-molecule GLP-1 receptor agonist developed by Eli Lilly. Unlike injectable GLP-1 peptides, it is a non-peptide compound absorbed orally without food restrictions, representing a major convenience advancement. Phase 2 trials showed up to 9.4% weight loss at 36 weeks, and Phase 3 trials (ATTAIN program) are ongoing for obesity and type 2 diabetes.
- Half-Life
- ~3–5 hours (longer systemic circulation vs FST-344)
- ~12 hours (once-daily oral dosing)
- Admin Route
- SubQ, IM
- Oral
- Research
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- Typical Dose
- No established human dosing protocol
- 12 mg → 24 mg → 36 mg → 45 mg
- Frequency
- Research use only
- Once daily
- 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
- Oral pill — no injections required
- Once-daily dosing without food restrictions (unlike oral semaglutide)
- Up to 9.4% body weight reduction in Phase 2 at 36 weeks
- Significant HbA1c reduction in type 2 diabetes trials
- Small-molecule stability — no cold chain requirements
- Broadens access for injection-averse patients
- Potential class-defining convenience advantage over injectable GLP-1s
- 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, dose-dependent)
- Vomiting
- Diarrhea
- Decreased appetite
- +2 more
- Stacks With
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