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Memory, mood, sleep.
The category with the hardest delivery problem and the thinnest evidence.
5 compounds tracked in this category
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In theory, this class is designed to improve memory, focus, mood or sleep by acting directly on brain tissue, supporting neuronal repair, modulating neurotransmitter systems, or protecting against ischaemic damage. The first obstacle is delivery: the blood-brain barrier excludes most large molecules by design. The second is that most of these were studied for serious neurological conditions, not for sharpening a healthy brain.
Unmarked, FDA approved° legal over the counter† under FDA review, not yet permitted* not FDA approved‡ documented safety concern
| Compound | What is known |
|---|---|
| Semax† | Advisory panel voted 8–5 in favor July 2026, reviewed for cerebral ischemia. Not the nootropic use it is marketed for. Human data is limited and mostly older. |
| Selank* | Off Category 2, not authorized. Limited Russian trial data. |
| DSIP / Emideltide* | The one rejection of the seven. On minimal human evidence, the advisory panel voted against, 6–7. If you see this marketed as newly cleared, the seller misread the vote. |
| Cerebrolysin* | Not FDA approved. Used in some other countries. Trial results are mixed. |
| P21, PE-22-28, Adamax* | Preclinical only. |
The science behind this category
Any compound intended to act on the brain has to get there. The blood-brain barrier excludes most large molecules by design, and peptides are large. Some of these compounds are given intranasally on the theory that olfactory routes bypass the barrier. A real mechanism, but one where the fraction actually reaching brain tissue is poorly quantified for most of them.
Semax, Selank, Cerebrolysin and several others come out of Soviet and Russian pharmacology, where they were developed and in some cases approved for specific clinical indications. That history is genuine, but the trials are often older, smaller, and reported in ways that do not translate cleanly to current evidentiary standards. Western replication is limited.
This is the category's characteristic problem. Semax was reviewed by FDA for cerebral ischemia, a serious neurological indication. It is marketed for focus and mental clarity in healthy people. Those are entirely different claims requiring entirely different evidence, and data for the first says nothing about the second. The same pattern applies across most of this category.
Emideltide, better known as DSIP or delta sleep-inducing peptide, was the only compound of the seven reviewed in July 2026 to receive an unfavourable vote, 6–7. If you encounter it marketed as newly cleared alongside the others, the seller has misread the outcome.
P21, PE-22-28, Adamax and similar compounds have no human data whatsoever. They are laboratory research tools that reached consumer marketing without passing through any clinical stage. There is nothing to evaluate.
Understanding a category is the first step. Whether any of it applies to you is a question for a licensed physician who knows your history.
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