# Peptide Friend — Cognitive & Nootropic Research Peptides: Semax, Selank, DSIP > Peptide Friend is a reference desk for Cognitive & Nootropic research peptides — Semax, Selank and DSIP — summarized from peer-reviewed literature. A digest, not a vendor or clinic. A plain-English guide to what Semax, Selank and DSIP were actually studied for — the evidence, the gaps, and the honest limits of what each one can claim. ## The short version Peptide Friend is a reading desk, not a store. It collects what the published research literature actually says about three short peptides that keep appearing in conversations about **cognition, mood, anxiety and sleep**: Semax, Selank and DSIP. A *peptide* is simply a short chain of amino acids — the same building blocks that make up proteins, only far smaller — and each of these three has been synthesized and studied because it appears to nudge brain chemistry in ways researchers found interesting. 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 far the evidence actually reaches. A significant amount of it is in rats and mice. Most of it originates from a small number of Russian research institutions. None of these is an approved medicine in the United States or the European Union. We do not sell anything, we do not give medical advice, and we never present a human dose. ## What are research peptides? A *peptide* is a chain of amino acids shorter than a full protein. Because they are small and structurally specific, peptides can sometimes interact with receptors or enzymes in ways that switch particular processes on or off. A *research peptide* is one that has been synthesized in a laboratory and studied in cells, animals, or occasional early human pilots — but has **not** been approved by a regulator as a medicine for general human use. When this site reports a number — a dose, a time point, an effect size — it reports it the way the original study did: *studied at 50 micrograms per kilogram in rats*, or *in a small Russian clinical cohort with generalized anxiety disorder*. That framing is not a hedge; it is the accurate description of what the evidence actually is. ## How these three fit into cognitive research The three peptides on this desk share a rough neighborhood — the brain — but they approach it from different angles, which is why they sit together. - [**Semax**](/semax) is a synthetic seven-amino-acid analog of an ACTH fragment, with a C-terminal tripeptide added to slow breakdown. It has been studied in Russian clinics and registered there as a prescription drug for stroke and cognitive impairment, and in rodent models it rapidly changes neurotrophin (BDNF, NGF) gene expression [3][4]. It is the most mechanistically active of the three and the one most associated with focus and clarity in community reports — though almost all human data come from a single research tradition and have not been independently replicated in Western trials. - [**Selank**](/selank) is the lead compound on this desk. It is a tuftsin analog studied in Russia as a non-sedating anxiolytic, and it has the most human data of the three — including a small Russian RCT in generalized anxiety disorder reporting anxiolytic effects without the sedation or dependence of benzodiazepines [11]. Its mechanism runs through GABAergic modulation and enkephalin-degrading enzyme inhibition [6][12]. - [**DSIP**](/dsip) is a different creature entirely. It is a naturally occurring nonapeptide first isolated from sleeping-rabbit blood in the 1970s and studied for sleep promotion, stress-hormone modulation, and longevity. Despite decades of work it has no identified receptor, no identified gene, and a 2006 review in *Journal of Neurochemistry* called it a "still unresolved riddle" [14]. A large share of people who try it report no effect at all — which this desk treats as part of the honest record. Read each page, or [compare these peptides](/compare) side by side. ## A note on how this desk reads the literature Peptide Friend is a cross-referenced literature digest organized around a single commitment: the evidence is described at its true strength, not rounded up. Where a study is in rats, we say so. Where the human data are a single small trial from a single country, we say so. Where a popular claim is not supported by the published record, we say so. Community reports — what people say they experience when using these peptides outside of clinical settings — are included in the per-compound pages where the source material contains them, clearly labeled *anecdotal, not clinical evidence*, and kept rigorously separate from cited research findings. The point is a calm, honest map of what is known, what is uncertain, and what remains genuinely unresolved. --- A skeptic's reading desk: peer-reviewed citations on neuroactive peptides, no doses, no diagnoses, and nothing for sale.