Reviewed by The Peptide Dispatch Editorial Team · Last reviewed July 6, 2026
PE-22-28 (PE22) is a cognitive peptide, at the preclinical stage in the published literature. PE-22-28 is a seven-amino-acid peptide fragment derived from Cerebral Dopamine Neurotrophic Factor (CDNF), a protein that belongs to the evolutionarily conserved MANF/CDNF family of neurotrophic factors. CDNF was discovered in 2007 and found to protect and restore dopaminergic neurons in animal models of Parkinson's disease. PE-22-28 represents the active fragment responsible for much of CDNF's neuroprotective activity. The peptide works by modulating the unfolded protein response (UPR) in the endoplasmic reticulum, a cellular stress pathway implicated in multiple neurodegenerative conditions. Research suggests PE-22-28 may improve cognitive function, enhance memory consolidation, and provide protection against age-related cognitive decline. It has become popular in the biohacking community as a nootropic peptide.
PE-22-28 is a seven-amino-acid peptide fragment derived from Cerebral Dopamine Neurotrophic Factor (CDNF), a protein that belongs to the evolutionarily conserved MANF/CDNF family of neurotrophic factors. CDNF was discovered in 2007 and found to protect and restore dopaminergic neurons in animal models of Parkinson's disease. PE-22-28 represents the active fragment responsible for much of CDNF's neuroprotective activity. The peptide works by modulating the unfolded protein response (UPR) in the endoplasmic reticulum, a cellular stress pathway implicated in multiple neurodegenerative conditions. Research suggests PE-22-28 may improve cognitive function, enhance memory consolidation, and provide protection against age-related cognitive decline. It has become popular in the biohacking community as a nootropic peptide.
| Research Status | Preclinical |
|---|---|
| Half-Life | 2-4 hours (estimated) |
| Administration | Subcutaneous injection, Intranasal |
| Doses Reported in Published Studies | 50-100 mcg |
| Molecular Weight | 796.9 Da |
| Molecular Formula | C35H63N11O10 |
PE-22-28 acts on the unfolded protein response (UPR) pathway, reducing endoplasmic reticulum stress and promoting neuronal survival. It modulates MANF/CDNF signaling to protect dopaminergic neurons and enhance cognitive function.
PE-22-28 is a seven-amino-acid peptide fragment derived from Cerebral Dopamine Neurotrophic Factor (CDNF), a protein that belongs to the evolutionarily conserved MANF/CDNF family of neurotrophic factors. CDNF was discovered in 2007 and found to protect and restore dopaminergic neurons in animal models of Parkinson's…
PE-22-28 acts on the unfolded protein response (UPR) pathway, reducing endoplasmic reticulum stress and promoting neuronal survival. It modulates MANF/CDNF signaling to protect dopaminergic neurons and enhance cognitive function.
PE-22-28 is at the following stage in the published literature: Preclinical. All information is for research and educational purposes only.
Reported half-life: 2-4 hours (estimated).
Reported administration route in the literature: Subcutaneous injection, Intranasal. This is not a recommendation for human use.
Educational content, not medical advice. Effects described are drawn from cited research in study subjects.