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ToolsCompareAOD-9604 vs Follistatin 315

AOD-9604 vs Follistatin 315

Side-by-side comparison of key properties, dosing, and research.

Fat Loss & Metabolic
AOD-9604
Anabolic & IGF
Follistatin 315
Summary
AOD-9604 is a modified fragment of human growth hormone (residues 177-191) with an additional tyrosine residue that significantly enhances bioavailability. Originally developed as an anti-obesity drug by Metabolic Pharmaceuticals, it stimulates lipolysis and inhibits lipogenesis without the diabetogenic effects of full GH.
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.
Half-Life
30-45 minutes injectable; longer with nasal spray formulation
~3–5 hours (longer systemic circulation vs FST-344)
Admin Route
SubQ, Intranasal, Oral
SubQ, IM
Research
Typical Dose
300-600 mcg
No established human dosing protocol
Frequency
Once daily
Research use only
Key Benefits
  • Selective fat loss without anabolic side effects
  • No effect on blood glucose or insulin resistance
  • Improved bioavailability over Fragment 176-191
  • GRAS (Generally Recognized As Safe) status in Australia
  • Potential cartilage repair and anti-inflammatory properties
  • Does not suppress natural GH production
  • 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
Side Effects
  • Localized injection site reactions
  • Headache (rare)
  • Hypoglycemia risk in combination with insulin (very rare)
  • 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
Stacks With