P021 (also “P21”) is a synthetic small neurotrophic compound (Ac-DGGL(A)G-NH₂) derived from the biologically active region of ciliary neurotrophic factor (CNTF). It was engineered in academic neuroscience as a compact, metabolically stable, orally active mimetic of CNTF’s neurogenic activity — chemically distinct from the unrelated p21 / CDKN1A cell-cycle protein that shares the shorthand.
In preclinical research (cell cultures and rodent models of Alzheimer’s disease and ageing) P021 has been reported to enhance hippocampal neurogenesis, raise BDNF and reduce abnormal tau hyperphosphorylation. It is a frontier, rarely-stocked research compound rather than a mainstream peptide.
Supplied as a lyophilized powder. See the monograph and handling notes for details and references.