P21
Synthetic peptide derived from CNTF that promotes neurogenesis.
Regulatory status (as of Sept 2026)
Not FDA-approved; no human trials.
See the FDA peptide regulatory tracker · Read our July 27, 2026 dispatch on the FDA PCAC peptide vote3 studies referenced · Last reviewed Oct 1, 2026 · Reviewed by The Peptide Dispatch Editorial Team · How we research & label content
P21 is a compound studied only in animals and lab experiments so far. Synthetic peptide derived from CNTF that promotes neurogenesis.
| Half-life | Not established in published research |
|---|---|
| How it's given in studies | Oral (mice) |
| Research stage | Preclinical (animal) |
| Dosing | Published research: No published human dosing detailsMice (3xTg-AD): P021 given orally in diet for months; no human dosing.Community-reportedCommunity-reported: 100–400 mcg, intranasal or subcutaneous |
Published-research dosing is what was given in the cited studies (species and units as reported). Community-reported dosing is what users describe, not from clinical studies. Neither is a recommendation. Not medical advice.
Where each point comes from: Clinicalhuman trials and FDA labels Lab / animalrodent, cell and ex vivo studies Community-reporteduser experience and commonly used protocols, not from clinical studies
In plain terms: It is a nerve-growth compound that protected memory and brain connections in a mouse model of Alzheimer's disease. From mouse studies only: in the 3xTg-AD Alzheimer's mouse model, P021 (a CNTF-derived neurotrophic compound given orally in the diet) prevented dendritic and synaptic deficits and cognitive impairment (Baazaoui 2017; Kazim 2014). Its proposed mechanism is CNTF-related neurotrophic signalling. No human data have been published.
How to read this: Each item below is an effect observed in research subjects in the cited studies — think of Dexter, our stand-in research subject. These are findings from the literature, not results you should expect, and not medical advice.
Community-reportedSome users report running P21 at 100–400 mcg (intranasal or subcutaneous). This is not a recommendation.
Community reports are anecdotal, vary widely in product quality and purity, and are not medical advice. Talk to a licensed provider.
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| Peptide | Half-Life | Route | Research Status |
|---|---|---|---|
| P21 | Unknown | Oral (mice) | Preclinical (animal) |
| Dihexa | Unknown | Oral or intraperitoneal (rodent studies only); no human administration published | Preclinical (animal) |
| FGL (L) | Unknown | Subcutaneous injection | Preclinical (animal) |
| PE-22-28 | No published PK data found | Subcutaneous injection, Intranasal | Preclinical (animal) |
| Pinealon | No published PK data found | Oral, Sublingual | Phase 1 / early human |
Values reflect figures reported in published research. Compare any peptides side-by-side →
This peptide belongs to the Cognitive category. View All Cognitive Peptides
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Dosing, half-life figures, and mechanism descriptions on this page are compiled from peer-reviewed published research, with the species and study type stated where reported. Figures labeled “Dosing used in published research” describe what was given in those studies and do not constitute dosing recommendations for any human use. Each cited paper is listed with DOI and PubMed links in the References section above. Found an error? Contact us.