SS-31 vs Thymalin
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.
SS-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 profileThymalin
Thymus-derived peptide bioregulator developed in Russia containing a mixture of low-molecular-weight peptides extracted from calf thymus. Primarily studied for reversing immunological aging (immunosenescence) and extending healthy lifespan. Vladimir Khavinson's longitudinal research on elderly patients links thymalin administration to significant improvements in immune markers and all-cause mortality reduction.
Full profile| SS-31 | Thymalin | |
|---|---|---|
| Category | Anti-Aging & Longevity | Anti-Aging & Longevity |
| Also known as | Elamipretide, MTP-131, Bendavia, Szeto-Schiller peptide 31 | thymic peptide bioregulator, T-activin extract, thymus peptide, thymic bioregulator |
| Evidence | Investigational (in trials) | Research-stage |
| Dosing range | 1mg–10mg mg, daily or every other day | 5mg–20mg mg, 5–10 day course, 1–2x per year |
| Administration | Subcutaneous injection, Intravenous (clinical trials) | Intramuscular injection, Subcutaneous injection |
| Key side effects | Injection site reactions, Nausea (rare), Generally well-tolerated in clinical trial populations | Injection site reactions, Mild fever (rare), Temporary increase in immune activity (desired response), Rare hypersensitivity |
| Cited sources | 2 references | 2 references |
Key differences
- Evidence level differs: SS-31 is investigational (in trials), while Thymalin is research-stage.
- Administration: SS-31 — Subcutaneous injection, Intravenous (clinical trials); Thymalin — Intramuscular injection, Subcutaneous injection.
- Frequency: SS-31 is typically daily or every other day; Thymalin is 5–10 day course, 1–2x per year.
How each works
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.
Thymalin
Thymalin contains multiple bioactive peptides that stimulate T-lymphocyte differentiation and restore thymic function that declines with age. In Khavinson's 6-year controlled trial of elderly patients (78–89 years), annual thymalin courses were associated with significantly lower mortality and improved immune parameters vs. controls. Proposed mechanisms include telomerase activation in immune cells and restoration of thymic epithelial cell function.
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.