P21vsSS-31
P21 vs SS-31 — independent comparison of uses, administration, pricing across providers, and key differences. Last reviewed April 21, 2026.
Quick Verdict
Based on clinical evidence and real patient data
A 21-amino-acid peptide that mimics the action of ciliary neurotrophic factor (CNTF). Studied for neurogenesis, cognitive improvement, and neuroprotection. Shows promise in animal models for enhancing memory consolidation and protecting against neurodegenerative decline.
A mitochondria-targeting tetrapeptide that concentrates in the inner mitochondrial membrane, protecting cardiolipin from oxidative damage. Restores mitochondrial function in aged and metabolically stressed cells, with clinical trials in heart failure and Barth syndrome.
Best choice depends on your insurance, budget, and treatment history.Take the quiz to get a personalized recommendation.
P21 vs SS-31: At a Glance
Full comparison across all key factors.
| Factor | P21ALLY PICK | SS-31 |
|---|---|---|
| Category | cognitive | anti-aging |
| Also Known As | CNTF analog, Colostrinin fragment | Elamipretide, Bendavia, MTP-131 |
| Administration | Intranasal spray | Subcutaneous injection |
| Prescription | Required | Required |
| Providers | 3 providers✓ Better | 2 providers |
| Common Uses |
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Data sourced from FDA prescribing information and peer-reviewed clinical trials. Prices reflect telehealth platform costs as of April 21, 2026. See our methodology.
Pricing by Provider
2 providers offer both P21 and SS-31.
| Provider | P21 | SS-31 | Consultation | Lab Testing |
|---|---|---|---|---|
 | $180/monthly | $280/monthly | Video Telehealth | Yes |
 | $230/monthly | $350/monthly | Video Telehealth | Yes |
 | $55/one-time | Not offered | Async Telehealth | No |
Key Differences
P21
More ProvidersA 21-amino-acid peptide that mimics the action of ciliary neurotrophic factor (CNTF). Studied for neurogenesis, cognitive improvement, and neuroprotection. Shows promise in animal models for enhancing memory consolidation and protecting against neurodegenerative decline.
SS-31
A mitochondria-targeting tetrapeptide that concentrates in the inner mitochondrial membrane, protecting cardiolipin from oxidative damage. Restores mitochondrial function in aged and metabolically stressed cells, with clinical trials in heart failure and Barth syndrome.
Which Is Right for You?
Choose P21if…
- You want a cognitive medication
- You prefer intranasal spray administration
- You want more provider options (3 available)
- Your primary goal is neurogenesis
- Your primary goal is memory consolidation
Choose SS-31if…
- You want a anti-aging medication
- You prefer subcutaneous injection administration
- 2 providers available on our platform
- Your primary goal is mitochondrial function
- Your primary goal is cellular energy
Frequently Asked Questions
What is the difference between P21 and SS-31?
Which is cheaper, P21 or SS-31?
Can I switch from P21 to SS-31?
Medical Disclaimer
This comparison is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider before starting, stopping, or changing any medication. Individual results may vary. The information presented reflects publicly available data and may not account for your specific health situation.