What it is
P21 is a small lab-made peptide. It copies 4 amino acids from CNTF, a protein that helps nerve cells grow and survive. The 4 amino acids are aspartic acid, glycine, glycine, and leucine. An acetyl cap is added to the front end. A cage-shaped adamantane group is added to the back end. These changes help it last longer and reach the brain. Scientists at the New York State Institute for Basic Research designed it. Adamax uses the same adamantane idea, but Adamax has never been tested. See the Adamax entry for that compound. Other names: P021, P-21, Ac-DGGL(A)G-NH2.
What researchers study it for
- New brain cell growth in the hippocampus
- Tau, a protein that tangles in Alzheimer's disease
- Memory in Alzheimer's model mice
- Tau levels in the brain fluid of old rats
What the studies found
1. Normal mice grew more new brain cells and did better on memory tests.
A 2010 study gave P21 by injection to healthy adult mice. They did better on learning and memory tests. More new nerve cells formed and matured in the dentate gyrus, a part of the hippocampus tied to memory. Mouse data only.
2. Alzheimer's model mice had less tau damage and better memory.
A 2014 study fed P21 in food for 12 months to mice bred to develop Alzheimer's-like changes. Harmful tau changes went down. Memory, new brain cell growth, and nerve cell connections improved. BDNF went up. Amyloid plaques only trended down. Mouse data only.
3. Old rats had lower tau in their brain fluid.
Tau in the fluid around the brain rises with age. A 2015 study fed P21 to old rats over a long period. Tau in the brain and brain fluid dropped to the level seen in young rats. The rats showed no immune reaction to the peptide. Rat data only.
4. Starting early kept Alzheimer's model mice from developing damage.
A 2017 study started P21 in Alzheimer's model mice at 3 months old, before damage appeared. Treated mice did not develop the usual brain cell loss, amyloid, or tau damage. Their memory held up. Fewer treated mice died during the study. Mouse data only.
5. Treatment from birth prevented Alzheimer's-like behavior in mice.
A 2021 study gave P21 to Alzheimer's model mice from birth to about 4 months old. The mice did not develop Alzheimer's-like behavior. Their nerve cell connections worked normally. Mouse data only.
How much research exists
A set of mouse and rat studies. All come from one research group in New York. No outside lab has repeated them. No human study has been published.
Facts
- Formula: C27H42N6O8
- Weight: about 579 g/mol. This matches the weight given in the 2021 study.
- CAS number: 1246751-68-7 (could not confirm)
- Sequence: Ac-Asp-Gly-Gly-Leu with an adamantane glycine mimic and an amide at the end
- Time in the blood: never measured
- Storage: no tested storage data. Similar peptides are kept as powder in the freezer.
Legal status
Not approved by the FDA or any other agency for any use.
For research use only. Not for human use. Nothing here is medical advice.