P21vsSermorelin
P21 vs Sermorelin — 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 growth hormone-releasing hormone (GHRH) analog that stimulates the pituitary gland to produce and secrete growth hormone naturally. Often used as a gentler alternative to direct HGH therapy.
Best choice depends on your insurance, budget, and treatment history.Take the quiz to get a personalized recommendation.
P21 vs Sermorelin: At a Glance
Full comparison across all key factors.
| Factor | P21 | SermorelinALLY PICK |
|---|---|---|
| Category | cognitive | growth-hormone |
| Also Known As | CNTF analog, Colostrinin fragment | Geref |
| Administration | Intranasal spray | Subcutaneous injection |
| Prescription | Required | Required |
| Providers | 3 providers | 14 providers✓ Better |
| 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
3 providers offer both P21 and Sermorelin.
| Provider | P21 | Sermorelin | Consultation | Lab Testing |
|---|---|---|---|---|
 | $55/one-time | $35/one-time | Async Telehealth | No |
 | $180/monthly | $175/monthly | Video Telehealth | Yes |
 | $230/monthly | $220/monthly | Video Telehealth | Yes |
| Not offered | Price unavailable | Hybrid | No | |
| Not offered | Price unavailable | Async Telehealth | No | |
| Not offered | Price unavailable | Hybrid | No | |
 | Not offered | $185/monthly | Video Telehealth | Yes |
| Not offered | Price unavailable | Async Telehealth | No | |
| Not offered | Price unavailable | Hybrid | No | |
 | Not offered | $160/monthly | Video Telehealth | No |
 | Not offered | $199/monthly | Async Telehealth | Yes |
 | Not offered | $199/monthly | Video Telehealth | Yes |
| Not offered | Price unavailable | Hybrid | No | |
| Not offered | Price unavailable | Hybrid | No |
Key Differences
P21
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.
Sermorelin
More ProvidersA growth hormone-releasing hormone (GHRH) analog that stimulates the pituitary gland to produce and secrete growth hormone naturally. Often used as a gentler alternative to direct HGH therapy.
Which Is Right for You?
Choose P21if…
- You want a cognitive medication
- You prefer intranasal spray administration
- 3 providers available on our platform
- Your primary goal is neurogenesis
- Your primary goal is memory consolidation
Choose Sermorelinif…
- You want a growth-hormone medication
- You prefer subcutaneous injection administration
- You want more provider options (14 available)
- Your primary goal is growth hormone optimization
- Your primary goal is improved sleep
Frequently Asked Questions
What is the difference between P21 and Sermorelin?
Which is cheaper, P21 or Sermorelin?
Can I switch from P21 to Sermorelin?
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.