Reviewed & approved by Dr. Nova Reyes · Last checked 2026-10-25. ← Back to Evidence Library
P21 (P021): what the evidence says
At a glance
P21 (research code P021) has never been tested in people in any published trial. Unknown
What it is: a small peptide-like molecule (Ac-DGGLAG-NH2) built from part of CNTF, a nerve growth factor, made by a New York research group. R1
What the evidence says: only studies in Alzheimer's-model mice, nearly all from the developing lab. R1, R2
Biggest risks: unknown in humans. Unknown
Rating
| Human Human evidence | No human data |
| Animal Animal evidence | Transgenic mouse studies R1, R2 |
| Regulatory | Not FDA-approved (no Drugs@FDA record) · Not approved anywhere in the world · WADA 2026: S0 (unapproved substances) applies R3 |
| Established human dose | None. Never studied in people |
Evidence verdict: Human: No human data · Animal: mouse studies Card verdict: No human data (cognitive claims rest on Alzheimer's-model mouse studies from the developing lab)
This page reports what studies used. It is not dosing advice.
Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source
What is it?
P021 is a CNTF-derived "neurotrophic peptide mimetic" developed at the New York State Institute for Basic Research. In mice it was given in food. R1, R2 Online sellers market it as a nootropic called "P21".
Does it work?
- Animal Older Alzheimer's-model mice: a year of P021 in food reduced abnormal tau and soluble amyloid. R1
- Animal Young Alzheimer's-model mice: starting from birth prevented memory problems at 4 months. R2
- Unknown People: none. Brain-boosting claims are anecdotal.
Is it safe?
- Unknown No human safety data.
Gray-market "research use only" P21 (P021): extra risks
Unknown contents. Products sold online as "research use only" or "not for human use" are not made under drug-quality rules, so identity, strength and sterility are unknown. This is a general caution; we have not found testing data for this product specifically. Unknown
Different route. Mouse studies used food; vendors sell injectable or nasal forms that have not been studied. Unknown
What we don't know
- Unknown Whether it works or is safe in people
- Unknown Whether studied results apply to vendor forms
Is it legal?
Not FDA-approved (no Drugs@FDA record, openFDA query Oct 24, 2026) and not approved anywhere in the world. WADA: not named on the 2026 Prohibited List; S0 bans at all times any unapproved substance in development that no other section covers, which describes P21 R3. WADA has not ruled on P21 by name.
Study details
These are doses researchers used, not recommendations.
R1–R2 Animal Animal
| Study | People / model | Route | Dose used | Follow-up | Reported | Side effects / dropouts | Citation |
|---|---|---|---|---|---|---|---|
| Kazim 2014 | 3xTg-AD female mice | Oral (diet) | See paper | 12 months | Less tau hyperphosphorylation; lower soluble Aβ | Not in abstract | PMID 25046994 |
| Wei 2021 | 3xTg-AD female mice | Oral (diet) | See paper | Birth to day 120 | Prevented cognitive impairment | Not in abstract | PMID 34057082 |
Full reference list (PubMed entries verified Oct 24, 2026)
- R1 Kazim SF, et al. Neurobiol Dis. 2014;71:110-30. PMID 25046994
- R2 Wei W, et al. J Alzheimers Dis. 2021;82(2):631-46. PMID 34057082
- R3 WADA. World Anti-Doping Code International Standard: Prohibited List 2026 (in force Jan 1, 2026). https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf (text read Oct 24, 2026)
Disclaimer
This page summarizes published research for education and harm reduction; it is not medical advice or a recommendation to use P21. Talk to a clinician you trust before using any drug, and report side effects to FDA MedWatch.
Approved for Adam Greene by Dr. Nova Reyes, 2026-10-25.