Three Peptides, One Question: What Does the Science Actually Say?

The short version

NewGen Peptides is a reading desk, not a store. It collects what the peer-reviewed literature says about three peptides that surface frequently in conversations about cognitive enhancement, anxiety management and sleep: Semax, Selank and DSIP.

A peptide is simply a short chain of amino acids — the same building blocks that make proteins, only far smaller. Each of these three has been studied because it appears to touch some part of the brain's signaling machinery: Semax by boosting growth factors like BDNF, Selank by modulating the inhibitory GABA system, DSIP by interacting with sleep-regulatory and stress-hormone pathways.

This guide does one job: it tells you, in plain language and with citations, what each peptide was tested on, in which species, and how strong that evidence actually is. None of these is an approved medicine in the United States or Europe. We do not sell anything, we do not give medical advice, and we never list a human dose.

If you are new to this territory, start with Semax — it has the deepest rodent mechanistic file and the most active research community. Then compare these peptides side by side.

What are research peptides?

Proteins in your body — a receptor on a neuron, a hormone from the pituitary, a structural component in connective tissue — are long amino-acid chains folded into specific shapes. A peptide is a much shorter chain of those same amino acids, sometimes only three to ten links long. Because they are compact and specific, peptides can behave like keys that fit particular cellular locks, shifting the activity of a receptor or an enzyme.

A research peptide is one that has been synthesized and characterized in the laboratory — in cell cultures, in animal models, occasionally in small human pilots — but has not been approved by a regulator as a medicine. In the United States these compounds are sold strictly for laboratory research; that framing matters, because it means human dosing, long-term safety and real-world effectiveness are largely unestablished.

When this site reports a number, it reports it the way the study did — for example, studied at 50 micrograms per kilogram in male Wistar rats via intranasal administration — never as a recommendation for people.

How these three fit into cognitive research

The three peptides on this desk approach the brain from different angles.

• Semax is the lead. It is a synthetic analog of a fragment of ACTH, the stress-response hormone, but without cortisol-releasing activity. Its most characterized actions in rodents are rapid upregulation of the neurotrophins BDNF and NGF, neuroprotection in ischemia models, and inhibition of enkephalin-degrading enzymes in human serum in vitro ^[3][4][7]. It is prescription-registered in Russia for stroke and cognitive impairment; it is a research chemical in most of the world.
• Selank approaches cognition through the anxiety axis. It is derived from tuftsin, an endogenous immune tetrapeptide, extended with a C-terminal Pro-Gly-Pro tail for metabolic stability. In rodents it acts as a positive allosteric modulator of GABA receptor binding and shifts GABA-related gene expression in frontal cortex, producing anxiety reduction without obvious sedation ^[8][10]. It also modulates BDNF in the hippocampus ^[11] and Th1/Th2 cytokine balance in human patients ^[12].
• DSIP is the most enigmatic of the three. First isolated in 1977 from sleeping-rabbit cerebral blood, it was named for its ability to enhance slow-wave EEG activity. Despite four decades of work, no receptor, gene or precursor has been identified, and a 2006 review concluded the sleep-promotion hypothesis is "extremely poorly documented and still weak" ^[14]. A small 1981 human trial did find improved sleep duration and quality in chronic insomniacs ^[17]; more recent work explores a BBB-crossing fusion peptide in animal insomnia models ^[13].

Together they sketch the cognitive-optimization question from different vantage points: neurotrophin-driven neuroprotection, GABAergic anxiety relief, and sleep-architecture support. Use the directory above to read each one in depth, or compare these peptides across a structured table.

How this desk reads the literature

NewGen Peptides is a cross-referenced literature digest. Each compound page summarizes the peer-reviewed studies for that peptide, cites them by number, and links to a single shared references list that aggregates every source across all three. Where the evidence is preclinical, single-lab, or from a narrow regional research tradition, we say so plainly — that caution is part of the record, not a footnote.

We describe study findings and cited safety cautions; we do not recommend, prescribe, or sell. The aim is a quiet, accurate account of what is known, so you can see where the signal is solid and where it is still mostly hypothesis.