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ToolsCompareTirzepatide vs Follistatin

Tirzepatide vs Follistatin

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

GLP-1 / Weight Loss Agonists
Tirzepatide
Anabolic & IGF
Follistatin
Summary
Tirzepatide is an FDA-approved dual GIP/GLP-1 receptor agonist that produces greater weight loss than semaglutide in head-to-head trials. SURMOUNT-1 trial showed average 21% body weight reduction at 72 weeks at the highest dose. Marketed as Mounjaro (diabetes) and Zepbound (obesity).
Follistatin is an endogenous glycoprotein that acts as a potent inhibitor of myostatin and activin, two proteins that limit muscle growth. By binding and neutralizing myostatin, follistatin removes the primary brake on skeletal muscle hypertrophy, enabling significant muscle growth beyond normal physiological limits. It is distinct from its isoforms Follistatin 315 and Follistatin 344 in tissue distribution and binding affinity.
Half-Life
~5 days
~3–5 hours (endogenous form)
Admin Route
SubQ
IM, SubQ
Research
Typical Dose
2.5 mg → 5 mg → 7.5 mg → 10 mg → 12.5 mg → 15 mg
50–100 mcg per injection site
Frequency
Once weekly, subcutaneous
Every other day or 2–3x per week
Key Benefits
  • Average 21% body weight reduction at highest dose (SURMOUNT-1)
  • Superior to semaglutide in head-to-head SURPASS trials
  • Dual GIP/GLP-1 mechanism for enhanced metabolic control
  • Significant reduction in HbA1c for type 2 diabetes
  • Improved cardiovascular risk markers
  • Reduces visceral fat preferentially
  • FDA-approved for T2DM (Mounjaro) and obesity (Zepbound)
  • Weekly dosing
  • Potent myostatin inhibition enabling supraphysiological muscle growth
  • Increases skeletal muscle mass and fiber size
  • May accelerate recovery from muscle injury
  • Potential benefits in muscular dystrophy and sarcopenia
  • Synergistic with IGF-1 and growth hormone in anabolic protocols
  • Animal studies show dramatic increases in muscle mass
  • Reduces muscle fibrosis in dystrophic models
Side Effects
  • Nausea (most common during titration)
  • Vomiting
  • Diarrhea or constipation
  • Abdominal pain
  • +3 more
  • Potential for excessive muscle growth if doses are not controlled
  • FSH suppression with implications for fertility in women
  • Theoretical risk of cardiac hypertrophy with prolonged high-dose use
  • Limited human safety data available
  • +1 more
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