# Semax: What the Neuroprotection and Neurotrophin Research Actually Shows > Semax, a synthetic ACTH(4-7) peptide, reduced cortical infarct volume and raised brain BDNF in rodent stroke models. A cited broadsheet digest of the neuroprotection and neurotrophin literature. A plain-English, fully cited reading of the neuroprotection-in-ischemia and BDNF/NGF literature — including, in plain sight, where the evidence stays preclinical, Russian, and single-region. ## The short version Semax is a small lab-made peptide — a chain of seven amino acids — built from a piece of a natural hormone called ACTH. It was designed in Russia in the 1980s as a brain-protecting, focus-supporting compound, and it is a prescription medicine in Russia and Ukraine. It is **not** approved by the FDA and is sold in the US only as a research chemical. In rats and mice, Semax has lowered the size of stroke damage in the brain and pushed up natural "growth factors" (BDNF and NGF) that help nerve cells survive and learn [1][4]. People who use it report a quick, clean kind of mental clarity — focus without the jitters of caffeine — but a real share of users feel little or nothing, and the effect fades within hours. What people report, including the downsides, is laid out on the [Semax effects](/effects) page. Everything below is research, not advice. ## What the Semax literature has demonstrated Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic heptapeptide — a chain of seven amino acids — engineered from the ACTH(4-7) fragment of adrenocorticotropic hormone, with a Pro-Gly-Pro (a three-amino-acid "tail" that slows the body's enzymes from chewing the peptide apart) grafted on the end [16]. It keeps the neurotrophic and behavioral activity of that hormone fragment while dropping the cortisol-releasing action of the full hormone. The headline finding is consistent and it comes from the stroke literature. Intranasal Semax given for six days in a rat model of focal prefrontal-cortex ischemia (reduced blood flow to a region of the brain) decreased the volume of cortical infarction — the size of the dead-tissue zone — and preserved memory on a passive-avoidance task [4]. Across cerebral ischemia models the protective signal has reproduced at the level of gene expression, protein expression, and inflammation [5][9][10][11]. The second pillar is neurotrophins. A single 50 microg/kg intranasal dose raised BDNF and NGF messenger RNA in the rat hippocampus and brainstem within hours [2], and at 50 and 250 microg/kg Semax increased BDNF protein in the basal forebrain and bound a specific, reversible site there with a dissociation constant (a measure of binding tightness) of 2.4 nM [1]. Reproducibility across heterogeneous rodent stroke models is itself the finding here — a single Russian research line, repeated, rather than a Western randomized trial. ## Not a stimulant, and not a clinic Semax is classed as a nootropic — a compound studied for possible cognitive support with low toxicity — not a stimulant. In mice, 0.15 mg/kg raised the serotonin metabolite 5-HIAA and potentiated amphetamine-evoked dopamine release, but did not by itself raise baseline dopamine [20]. That nuance matters: Semax does not flood the brain with dopamine the way a stimulant does; it shifts neurotrophic and monoaminergic signaling more quietly. This site is an editorial digest. It is not a clinic, it does not sell anything, and it does not tell anyone what to take. For the question most readers arrive with — [what is semax peptide used for](/what-is-semax) — there is a dedicated page reading the research use cases. The mechanism and the key studies are gathered in the [Semax research](/research) summary, the doses used in animals are in the dosing-research section, and the full source list is in the [Semax references](/references). ## A peptide engineered for stability The design of Semax explains a lot about its behavior. The starting point was the ACTH(4-7) fragment (Met-Glu-His-Phe), known to carry neurotrophic and behavioral activity but too short-lived to be practical because the body's enzymes degrade it quickly. The fix was chemical: graft a Pro-Gly-Pro tail onto the end to slow that breakdown [16]. The result is the stabilized heptapeptide — and, usefully, the Pro-Gly-Pro tail is itself a biologically active metabolite that independently activates neurotrophin gene transcription after it splits off [8]. That is why the literature so often credits the metabolite with the longer effects: Semax was, in effect, built as a delivery system for a sequence the brain responds to. Research-community analogs such as N-Acetyl Semax Amidate push the same idea further, adding chemical caps to slow degradation more, though their independent published pharmacology is thinner than the parent peptide's. ## Where the evidence stops Honesty is part of the record. The large majority of Semax research originates from a small number of Russian institutions, much of the clinical literature is in Russian and not indexed in Western databases, and there are no published Western randomized controlled trials [18][19]. Most mechanistic and efficacy data come from rats and mice; the few human studies are older EEG and clinical reports [17][18]. The intact heptapeptide is also cleared fast. After a 50 microg/kg intranasal dose in rats, only about 0.093% of the dose per gram reached the brain at two minutes, roughly 80% of it still intact, the rest already broken down [6]. Longer behavioral effects are attributed to the active Pro-Gly-Pro metabolite — a reasonable inference, not a fully resolved account [8]. Read the [Semax effects](/effects) page for what people actually report, clearly labeled as anecdote rather than trial data. --- Filed from the published record on Semax like a front-page dispatch — the rodent neuroprotection and BDNF findings set in plain ink, the Russia-and-Ukraine-only registration and the missing Western trials printed in the same column, with no clinic behind the masthead and nothing here dosed, sourced, or sold.