Cortagen
Cortagen, a peptide. Synthetic tetrapeptide Ala-Glu-Asp-Pro from the Khavinson short-peptide programme, derived from the bovine cortex preparation Cortexin…
Synthetic tetrapeptide Ala-Glu-Asp-Pro from the Khavinson short-peptide programme, derived from the bovine cortex preparation Cortexin: PMID:15159690 verbatim, "The synthetic tetrapeptide Cortagen (Ala-Glu-Asp-Pro) was obtained by directed synthesis based on amino acid analysis of natural brain cortex peptide preparation Cortexin." The published mechanism is transcriptional and epigenetic rather than receptor-mediated — a mouse-heart microarray found "234 clones (1,53% of the total number of clones) with significant changes of expression that matched 110 known genes" (PMID:15159690), and in aged human lymphocytes "each of the studied peptide bioregulators (Ala-Glu-Asp-Gly; Lys-Glu-Asp-Ala; Ala-Glu-Asp-Pro and Lys-Glu) has a selective effect on definite regions of chromosomes" (PMID:37042594). NO RECEPTOR AND NO MOLECULAR TARGET IS NAMED IN ANY INDEXED ABSTRACT.
PubChem CID 18439621 (C17H26N4O9, 430.4), CAS 335591-03-2, re-queried 2026-09-26; the synonym list is name-specific ("Cortagen") and the IUPAC name resolves to Ala-Glu-Asp-Pro, so identity and mass agree. FUNCTIONAL EFFECT, rat sciatic nerve regeneration, verbatim: "increased the growth rate and conduction velocity in the regenerating nerve fibers by 27% and 40%, respectively" (PMID:11276314). CORROBORATING BUT NOT SOLE-SUBJECT: PMID:37042594 tests four peptides at once (Epitalon, Livagen, Cortagen, Vilon) in lymphocytes from 75-88-year-old donors, so its chromatin finding reaches this sequence as one arm of four rather than as a dedicated study. THE INDEXED CORPUS IS 13 RECORDS on `Cortagen[tiab]`, all rat, mouse, chicken, cell culture or review — no primary human study exists to find. SEARCH NOTE: Cortexin is a DIFFERENT thing, the polypeptide complex this tetrapeptide was derived from, and papers about Cortexin are not papers about Cortagen even where the two are discussed together (PMID:21476278 studies both). HUMAN USE IS ASSERTED BUT NOT DOCUMENTED: PMID:15159690 says "In humans, Cortagen demonstrated a pronounced therapeutic effect upon the structural and functional posttraumatic recovery of peripheral nerve tissue" — a background sentence in a mouse microarray paper, with no dose, no n, no route and no trial identifier. That is the secondary-citation shape HYGIENE R2 rejects, so it is recorded as an assertion and not treated as human exposure.
Sources: PMID:15159690, PMID:11276314, PMID:37042594