GDF-11 (Growth Differentiation Factor 11) vs SS-31
A neutral, side-by-side comparison of two anti-aging & longevity peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.
GDF-11 (Growth Differentiation Factor 11)
TGF-β superfamily member proposed as a 'young blood factor' — circulating GDF-11 declines with age, and young plasma transfusion in parabiosis experiments reversed aging phenotypes in mice. A high-profile but contested research area: some studies show rejuvenating effects in heart, muscle, and brain; others using purified recombinant GDF-11 show cardiac hypertrophy and muscle wasting at pharmacologic doses.
Full profileSS-31
SS-31 (Elamipretide) is a mitochondria-targeted peptide that concentrates in the inner mitochondrial membrane, protecting cardiolipin and restoring mitochondrial function. It is being studied for heart failure, aging, and metabolic disease. One of the most exciting longevity-adjacent peptides in current research.
Full profile| GDF-11 (Growth Differentiation Factor 11) | SS-31 | |
|---|---|---|
| Category | Anti-Aging & Longevity | Anti-Aging & Longevity |
| Also known as | GDF11, Bone Morphogenetic Protein 11, BMP-11, young blood factor | Elamipretide, MTP-131, Bendavia, Szeto-Schiller peptide 31 |
| Evidence | Research-stage | Investigational (in trials) |
| Dosing range | 0.1mg/kg–1mg/kg mg/kg, every 3–7 days (SC); research protocols vary widely | 1mg–10mg mg, daily or every other day |
| Administration | Subcutaneous injection, Intravenous (research) | Subcutaneous injection, Intravenous (clinical trials) |
| Key side effects | Cardiac hypertrophy (at pharmacologic doses — the key safety concern), Muscle wasting and weight loss, Reproductive effects (GDF-11 inhibits spermatogenesis and folliculogenesis), Cachexia-like syndrome at high doses | Injection site reactions, Nausea (rare), Generally well-tolerated in clinical trial populations |
| Cited sources | 2 references | 2 references |
Key differences
- Evidence level differs: GDF-11 (Growth Differentiation Factor 11) is research-stage, while SS-31 is investigational (in trials).
- Administration: GDF-11 (Growth Differentiation Factor 11) — Subcutaneous injection, Intravenous (research); SS-31 — Subcutaneous injection, Intravenous (clinical trials).
- Dosing units differ: GDF-11 (Growth Differentiation Factor 11) is dosed in mg/kg, SS-31 in mg — they operate at different scales.
- Frequency: GDF-11 (Growth Differentiation Factor 11) is typically every 3–7 days (SC); research protocols vary widely; SS-31 is daily or every other day.
How each works
GDF-11 (Growth Differentiation Factor 11)
The 2013–2014 parabiosis studies from Amy Wagers' lab at Harvard proposed GDF-11 as the primary rejuvenating factor in young blood. However, subsequent work by Lee and others showed that purified recombinant GDF-11 at pharmacologic doses caused cardiac hypertrophy, muscle atrophy, and weight loss — opposite of the proposed rejuvenating effects. The field now views GDF-11 as highly dose-sensitive with a narrow therapeutic window, if one exists at all.
SS-31
SS-31 selectively accumulates in mitochondria and binds cardiolipin — a phospholipid critical for the electron transport chain. By stabilizing cardiolipin, SS-31 restores ATP production, reduces reactive oxygen species (ROS), and prevents mitochondrial permeability transition. Animal studies show dramatic reversal of mitochondrial dysfunction in aged tissues.
This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.