Follistatin vs SS-31 (Elamipretide)
Side-by-side comparison of key properties, dosing, and research.
Anabolic & IGF
FollistatinAnti-Aging & Longevity
SS-31 (Elamipretide)- Summary
- 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.
- SS-31 (Elamipretide) is a synthetic mitochondria-targeting tetrapeptide that concentrates in the inner mitochondrial membrane and protects cardiolipin from oxidative damage. It is one of the most promising mitochondrial longevity compounds, studied in clinical trials for heart failure, renal disease, and age-associated mitochondrial dysfunction.
- Half-Life
- ~3–5 hours (endogenous form)
- ~2–5 hours
- Admin Route
- IM, SubQ
- SubQ
- Research
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- Typical Dose
- 50–100 mcg per injection site
- 5–10 mg
- Frequency
- Every other day or 2–3x per week
- Daily to several times per week
- Key Benefits
- 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
- Restores mitochondrial function and ATP production
- Protects inner mitochondrial membrane cardiolipin
- Reduces mitochondrial reactive oxygen species (ROS)
- Improves exercise capacity and reduces fatigue
- Cardioprotective — studied in heart failure trials
- Renoprotective — reduces ischemic kidney injury
- Anti-aging via mitochondrial preservation
- Potential in neurodegenerative disease prevention
- Side Effects
- 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
- Injection site irritation
- Nausea (rare)
- Generally well-tolerated in clinical trials
- Stacks With
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