Nootropic peptides
Peptides studied for memory, mood, focus and sleep rather than for body composition.
Nothing in this category is FDA-approved for memory, focus or mood. Some are approved medicines outside the US, one is an FDA-approved drug for a completely unrelated use, and several have never been given to a person in a published trial. The table below says which is which.
What are nootropic peptides?
They are peptides people take for the brain rather than the body: memory, focus, mood, anxiety and sleep. The label is a use, not a chemical family. The compounds here do not share a mechanism as a group: several copy a growth factor, one blocks a potassium channel, one is a hormone you already make, and one is not a single molecule at all. The thing they genuinely have in common is regulatory. Not one of them is approved by the FDA to improve cognition.
The other thing worth knowing before you read further is how thin the human evidence is. A few have been through real clinical programmes abroad. Several have never been given to a person in a published trial at all, so everything written about them online describes what happened in mice.
| Compound | What it is | Where the research came from | Human evidence |
|---|---|---|---|
| Selank | Synthetic analog of tuftsin, a short peptide the immune system makes. | Institute of Molecular Genetics, Russian Academy of Sciences | Used clinically in Russia for generalised anxiety disorder, where it went through phase 3 trials. Not FDA-approved. |
| DSIP | Nine amino acids isolated from rabbit brain in the 1970s, named for the delta-wave sleep it appeared to trigger. | University of Bern, Switzerland | Small intravenous trials in chronic insomnia in the 1980s, six to fourteen people each, with mixed results. Nothing modern. |
| Semax | Seven amino acids taken from the ACTH(4-10) fragment of a pituitary hormone, with the hormonal activity engineered out. | Institute of Molecular Genetics, Russian Academy of Sciences | An approved medicine in Russia for ischemic stroke and related brain injury. Not FDA-approved. |
| Oxytocin | A hormone your body already makes, best known for labor and social bonding. | Endogenous hormone, first synthesised in the 1950s | FDA-approved as an injection to induce labor, which is not a cognitive use. For social behaviour, a 290-participant trial in the New England Journal of Medicine in 2021 found nasal oxytocin no better than placebo over 24 weeks. |
| Dihexa | A small molecule modeled on angiotensin IV, built to survive in the body long enough to reach the brain. | Washington State University | None published. Rodent cognition work only. |
| Cerebrolysin | Not a single peptide. A mixture of small peptides and amino acids produced from pig brain tissue. | EVER Neuro Pharma, Austria | Approved in dozens of countries for stroke and dementia, never in the US. A Cochrane review of the stroke trials found no reduction in deaths and probably more non-fatal serious adverse events. |
| DNSP-11 | Eleven amino acids cut from proGDNF, the precursor to a nerve growth factor. | University of Kentucky | None published. Rat and macaque work on dopamine neurons. |
| FGL | Fifteen amino acids modeled on the FG loop of NCAM, a protein nerve cells use to stick to each other. | University of Copenhagen, Denmark | One Phase 1 safety study, a single nasal dose in 24 healthy men. The Alzheimer's programme that was meant to follow never ran. |
| P-21 | A modified four-amino-acid fragment based on the active region of ciliary neurotrophic factor (CNTF). | Iqbal lab, NYU and the Nathan Kline Institute | None published. Mouse models of Alzheimer's disease only. |
| PE-22-28 | Seven residues of spadin, itself cut from the sortilin propeptide. Blocks the TREK-1 potassium channel. | CNRS, Nice, France | None published. Mouse antidepressant models only. |
A compound with no published human trial is not the same as a compound that failed one, and neither is the same as an approved drug. Every entry below carries the PubMed count its evidence grade was derived from, so you can check the size of the literature yourself rather than take a letter for it.