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| Strength | Selection | Lowest listed total price | Price per mg | Supplier count | Compare |
|---|---|---|---|---|---|
| 12 mg | 1 vial | $119.00 | $9.92 | 2 | Compare |

122 products · 249 listings

153 products · 275 listings
4 listings from direct supplier captures. Capture and import dates record when data was obtained; they do not guarantee the supplier’s current price or stock.
Listings include out-of-stock and unconfirmed-stock records. Inclusion does not certify a supplier, a batch or a product. Read how matching and source dates work.
FROM PEPTIDES CALCULATOR
Source profile reviewed 2026-10-01 · Imported 2026-10-22. Read the full compound profile
P21 (published as P021) is a small synthetic peptide built from a four-residue stretch of human ciliary neurotrophic factor (CNTF), with an acetyl group on the N-terminus and an adamantylated glycine amide on the C-terminus added to slow enzymatic breakdown and help it cross the blood-brain barrier. It was designed in Khalid Iqbal's laboratory at the New York State Institute for Basic Research and is reported to work by competing with leukemia inhibitory factor and raising BDNF expression, which in rodents increased hippocampal neurogenesis, lowered GSK3-beta activity and tau phosphorylation, and improved memory. Every published study is in mice, rats or cell culture, nearly all from the originating laboratory, and the one in vivo test run elsewhere (a CDKL5 deficiency model) did not reproduce the BDNF increase. No human trial has been registered, no regulator has approved it, and it is sold only as a research chemical in 5 mg vials.
Understanding P21's role as a CNTF mimetic
Development, mechanism of action, and therapeutic applications
Background is reproduced from Peptides Calculator with attribution. The source describes compound-level research. It does not evaluate the identity, quality or suitability of a listed supplier’s product or batch.