--- title: "Semax: Benefits, Dosage, Side Effects & Nasal Spray" description: "Semax is a Russian nasal peptide built from a fragment of ACTH. How it raises BDNF, what stroke and memory studies found, side effects, and Semax vs Selank." canonical: "https://www.vitalsvault.com/peptides/semax" last-updated: 2026-08-22 --- # Semax: Benefits, Dosage, Side Effects & Nasal Spray > Semax is a Russian nasal peptide built from a fragment of ACTH. How it raises BDNF, what stroke and memory studies found, side effects, and Semax vs Selank. ![A man in his early fifties does a crossword with a pencil at a small marble cafe table by a window, reading glasses pushed up on his forehead,…](https://www.vitalsvault.com/_next/image?url=%2Fpublic-v3%2Fshoot%2Fpeptides%2Fpep-semax.webp&w=3840&q=75&dpl=shadow-production-f0162cb4d465-40992538108-1) Peptide Guide · Brain, mood and sleep # Semax Met-Glu-His-Phe-Pro-Gly-Pro, an ACTH(4–10) analogue Semax began as a slice of a stress hormone, trimmed until the stress part was gone. What was left is used in Russian stroke wards and studied for memory and attention. [Get early access to peptide care](https://www.vitalsvault.com/peptides-waitlist)[Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans) Free to join · One email when peptide care opens · Most lab results in 3–5 business days Studied forStroke recovery, memory and focus EvidenceHuman trials Taken asInto the nose; studies used nasal drops Studied forStroke recovery, memory and focus EvidenceHuman trials Taken asInto the nose; studies used nasal drops ## Semax, in short Semax is a seven-amino-acid peptide made from a fragment of ACTH, the pituitary stress hormone, with the hormonal activity removed. Given into the nose, it raised BDNF, a growth signal for brain cells, in the rat hippocampus and in the blood of stroke patients. It is used in Russia after stroke and studied for memory and attention. Its human trials are real but small and mostly from Russian groups. Medically reviewed by [Robert Lufkin, MD (opens in a new tab)](https://www.robertlufkinmd.com/) Chief Medical Officer, Vitals Vault · Updated October 29, 2026 · 15 sources ## At a glance Human trials TypeSynthetic heptapeptide, Met-Glu-His-Phe-Pro-Gly-Pro[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006) Based onACTH(4–7), followed by a Pro-Gly-Pro tail[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006) Studied forStroke recovery, memory, attention, optic nerve disease[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018)[8](https://www.vitalsvault.com/peptides/semax#source-asmarin-1997)[5](https://www.vitalsvault.com/peptides/semax#source-polunin-2000) Taken asInto the nose; studies used nasal drops[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006)[5](https://www.vitalsvault.com/peptides/semax#source-polunin-2000) Hormone activityNone, despite coming from ACTH[9](https://www.vitalsvault.com/peptides/semax#source-tsai-2007) ElsewhereUsed as a medicine in Russia[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018) FDA statusNot approved. 503A compounding allowed since October 29, 2026[13](https://www.vitalsvault.com/peptides/semax#source-ncpa) ## Before you consider Semax - Safety Published studies have not reported significant side effects, but many did not report safety in detail. The cited studies include no long-term data from outside Russia.[8](https://www.vitalsvault.com/peptides/semax#source-asmarin-1997)[4](https://www.vitalsvault.com/peptides/semax#source-gusev-2005)[14](https://www.vitalsvault.com/peptides/semax#source-fda-bulks) [Side effects and safety](https://www.vitalsvault.com/peptides/semax#safety) - Legal status Not FDA approved. Since October 29, 2026, 503A pharmacies may compound it for one patient with a prescription. In Russia it is a registered drug.[13](https://www.vitalsvault.com/peptides/semax#source-ncpa)[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018) [FDA status](https://www.vitalsvault.com/peptides/semax#fda-status) - How it’s taken Into the nose. Studies that name a form used nasal drops, and your prescriber sets the strength and schedule.[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006)[5](https://www.vitalsvault.com/peptides/semax#source-polunin-2000)[6](https://www.vitalsvault.com/peptides/semax#source-lebedeva-2018) [Forms and dosage](https://www.vitalsvault.com/peptides/semax#how-taken) ## How does Semax work? Semax’s best-understood effect is on a protein that helps brain cells grow and connect. - ### Raises a growth protein In rats, one dose raised a protein that helps brain cells grow, by up to 1.4 times.[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006) - ### Wakes up its receiving end The part of brain cells that receives that protein also became up to 1.6 times more active.[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006) - ### Changes immune and vessel activity After a stroke in rats, over half the genes it changed were tied to the immune system, and dozens to blood vessels.[7](https://www.vitalsvault.com/peptides/semax#source-medvedeva-2014) ## Semax benefits: what it is studied for Semax has more human data than most peptides in this guide, mainly from Russian clinics. Most trials are small and run by teams close to its developers. 1. Human study01 ### Stroke recovery Russian studies from 1997 to 2018 reported better recovery when Semax was added to standard stroke care, including higher BDNF and better daily-living scores.[3](https://www.vitalsvault.com/peptides/semax#source-gusev-1997)[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018) 2. Human study02 ### Memory and attention Its developers reported better memory and attention in healthy men under demanding conditions. Independent trials are still needed.[8](https://www.vitalsvault.com/peptides/semax#source-asmarin-1997) 3. Human study03 ### Chronic poor blood flow to the brain A 2005 study of 187 people with chronic cerebrovascular insufficiency reported stabilization and fewer strokes and transient ischaemic attacks.[4](https://www.vitalsvault.com/peptides/semax#source-gusev-2005) 4. Human study04 ### Optic nerve health Russian eye doctors reported better visual acuity and visual fields when Semax was added to standard care for optic nerve disease.[5](https://www.vitalsvault.com/peptides/semax#source-polunin-2000) ## What the research shows Human trials 1. 1 · Cells in a labNot cited This guide cites no findings at this level. Shows a mechanism 2. 2 · Animals Studied In rats, one nasal dose raised the brain growth protein by up to 1.4 times. After experimental stroke it shifted immune and vessel genes.[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006)[7](https://www.vitalsvault.com/peptides/semax#source-medvedeva-2014) Shows an effect in a body 3. 3 · People Studied Small Russian trials reported better stroke recovery with Semax added to standard care. A 2005 study of 187 people reported fewer strokes.[3](https://www.vitalsvault.com/peptides/semax#source-gusev-1997)[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018)[4](https://www.vitalsvault.com/peptides/semax#source-gusev-2005) Shows it works in people Semax has human trials for stroke and cerebrovascular disease, which sets it apart. Most were run in Russia by teams close to its developers, so independent trials elsewhere would strengthen the case.[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018) The full guide to Semax 9 min read · Medically reviewed by Robert Lufkin, MD ## A stress hormone with the stress taken out ACTH is the hormone your pituitary gland releases when something frightens you. It travels to the adrenal glands and tells them to make cortisol. Now take a short stretch from the front of that hormone, keep the part that seems to act on the brain, and discard the rest. That is roughly how a team in Moscow built Semax, and the hormone’s stress job did not survive the trimming. Semax is a chain of seven amino acids, Met-Glu-His-Phe-Pro-Gly-Pro. The first four come from ACTH, positions 4 to 7. The last three, Pro-Gly-Pro, were added on the end, a design choice usually explained as making the peptide harder for enzymes to chew up. A psychiatrist in Taipei summarizing the research described it as completely devoid of any hormonal activity, despite its parentage. By 1997, its developers could look back on 15 years of design and testing. They described Semax as one of the rare regulatory peptides to travel the whole road from basic research to practical medicine, and reported that it improved memory, attention, tolerance of low oxygen and brain circulation in animals and in people, with effects lasting most of a day after a nasal dose. Russian doctors went on to use it for ischaemic stroke, the kind caused by a blocked artery, and for some eye and neurological conditions. Outside Russia, it built a second life as a focus and memory peptide. To see why one molecule fits both stories, you have to look at what it does to a single growth factor.[8](https://www.vitalsvault.com/peptides/semax#source-asmarin-1997)[9](https://www.vitalsvault.com/peptides/semax#source-tsai-2007)[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006)[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018) ## How Semax works: BDNF, TrkB and the brain’s growth signals Brain-derived neurotrophic factor, BDNF, is a protein that helps neurons survive, sprout new branches and strengthen the connections that hold a memory. It is especially active in the hippocampus, the brain region that turns experience into long-term memory. If neurons were plants, BDNF would be the fertilizer. In 2006, researchers at the Institute of Molecular Genetics in Moscow gave rats a single nasal dose of Semax and measured what happened in the hippocampus. BDNF protein rose by up to 1.4 times. Activation of TrkB, the receptor that BDNF works through, rose by up to 1.6 times. The messages that cells use to build more of both rose too, BDNF threefold and TrkB twofold. Treated rats also made more conditioned avoidance responses, a standard measure of how well an animal learns to dodge an unpleasant cue. The study did not show that one caused the other, but the authors suggested Semax may affect learning by turning up both the supply of BDNF and the cell’s ability to hear it. There is a second layer. Animal work suggests Semax can amplify the effect of stimulant drugs on dopamine release in the brain. That observation led one researcher to propose it for attention-deficit hyperactivity disorder, though that paper was a hypothesis, and it reported no clinical trial testing the idea.[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006)[9](https://www.vitalsvault.com/peptides/semax#source-tsai-2007) ## Beyond BDNF: what Semax does to genes after a stroke If BDNF were the whole story, you would expect a stroke study to find mostly growth genes switched on. In 2014, the same Moscow institute ran a genome-wide scan of rat brain tissue after an experimental stroke, comparing animals given Semax with animals that had the stroke alone. The answer surprised them. More than half of the genes Semax changed belonged to the immune system. The effect was modest three hours after the blocked artery and much larger by 24 hours. Genes for immunoglobulins, the antibody family, and for chemokines, the signals that call immune cells to a site, were among the most notable groups. Blood vessels were the other theme. Semax shifted 24 vessel-related genes at three hours and 12 at a day, including genes involved in building and moving the cells that line vessel walls. The authors proposed that these immune and vascular gene changes are likely key to how Semax protects brain tissue. That is an interpretation of gene activity, not a measured repair. Put this next to the BDNF data and Semax looks less like a single-target drug and more like a nudge to the whole recovery environment around injured neurons. That is a rat result, but it helps explain why the clinical work centered on stroke.[7](https://www.vitalsvault.com/peptides/semax#source-medvedeva-2014) ## Semax for stroke: what the Russian trials found A clinical stroke report in 1997 set the pattern. Thirty patients in the acute phase of a hemispheric ischaemic stroke received Semax alongside intensive standard care, and 80 patients with similar strokes received standard care alone. The Semax group recovered general and focal deficits somewhat faster, with the clearest effect on movement. In 2005, the same group followed 187 people with chronic cerebrovascular insufficiency, the slow, grinding shortfall of blood supply that often comes before a stroke. They reported clinical improvement, a more stable course and a lower risk of stroke and transient ischaemic attacks, and described the drug as well tolerated, including by older patients. The most informative study came in 2018. Researchers followed 110 people after ischaemic stroke and split them two ways, by whether rehabilitation began early, about three months after the stroke, or late, about seven months after, and by whether they received Semax. They measured blood BDNF, muscle strength and the Barthel index, a score of how independently someone handles daily life. Semax raised blood BDNF regardless of when rehabilitation started, and kept it high through the study. Semax and higher BDNF both went with faster and better Barthel scores. The effect on weakness itself was smaller. These are encouraging results from small studies, mostly by one research network. Their abstracts do not describe randomization or blinding, and none was a large placebo-controlled trial.[3](https://www.vitalsvault.com/peptides/semax#source-gusev-1997)[4](https://www.vitalsvault.com/peptides/semax#source-gusev-2005)[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018) ## Rehab raises BDNF too Buried in the 2018 stroke study is a finding that changes how to think about Semax. In the patients who did not receive the peptide, BDNF still climbed, and it climbed faster and higher in those who started rehabilitation early. Starting rehab sooner went with the same blood marker the peptide moved. In other words, Semax and rehabilitation seem to pull on the same rope. The study found a positive link between BDNF levels and daily-living scores, and the strength of that link depended on when rehabilitation began. One way to read this is that BDNF is a shared thread in recovery, with more than one way to turn it up, though a correlation cannot show that BDNF drives either effect. This lines up with research in healthy people. A 2015 meta-analysis of 29 exercise studies found BDNF rose after a single workout, more so in people who trained regularly. Semax may add to a signal the body already knows how to make. That the two act on a common pathway is a hypothesis, built on correlations in one study. The practical question that follows is a good one. If a peptide and hard work move the same marker, the most interesting experiment is the combination. In the 2018 data, the peptide did not replace early rehabilitation. The authors credited both with faster recovery, which is a useful frame for anyone hoping a nasal spray will do the work of a training plan.[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018)[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006)[10](https://www.vitalsvault.com/peptides/semax#source-szuhany-2015) ## Semax for focus, memory and attention The reputation that brings most people to Semax has the thinnest published record in people. Its developers wrote in 1997 that it improved memory and attention in healthy men working under extreme conditions. The details are in a Russian-language review, and none of the studies cited here is a large controlled trial in healthy adults. Brain imaging offers a glimpse of something happening. In a 2018 study of 24 healthy volunteers, 14 received Semax and 10 a placebo, and resting-state MRI scans were taken before and 5 and 20 minutes after a nasal dose. The Semax group showed a larger frontal part of the default mode network, the set of regions active when the mind is at rest or wandering. A 2020 study from the same Moscow center scanned 52 healthy people after Semax, Selank or placebo. Both peptides changed the connection between the right amygdala, a hub for threat and emotion, and part of the right temporal cortex, each in its own way. These studies show measurable short-term changes in brain networks after a dose, without directly measuring the peptide in the brain. They do not show that anyone thought better. Eye doctors offer another clue. In a 2000 study of optic nerve disease, adding Semax to standard care was linked with better visual acuity, wider visual fields and better color vision. The optic nerve is brain tissue that happens to sit behind the eye, so this fits the broader picture of a peptide studied mostly for protecting injured neurons.[8](https://www.vitalsvault.com/peptides/semax#source-asmarin-1997)[6](https://www.vitalsvault.com/peptides/semax#source-lebedeva-2018)[12](https://www.vitalsvault.com/peptides/semax#source-panikratova-2020)[5](https://www.vitalsvault.com/peptides/semax#source-polunin-2000) Know your baseline before any peptide 120+ lab tests at Quest Diagnostics, every result reviewed by a licensed clinician. Most results in 3–5 business days. A baseline today gives your clinician something to compare against if you start Semax later. [Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans)[Get early access to peptide care](https://www.vitalsvault.com/peptides-waitlist) Full refund before your blood draw · No membership ## What we actually know in people Semax has more human data than most peptides in this guide. There are stroke studies spanning 1997 to 2018, a 187-person study in chronic cerebrovascular disease, an eye study and two imaging studies in healthy volunteers. That is a real record, and it is why Semax is used as a medicine in Russia. The record has two limits. Most of the work was published in Russian journals by research groups close to its developers, and the abstracts describe small studies, mostly without stated randomization or blinding, rather than large placebo-controlled trials. None of the studies cited here is an independent replication outside these Russian groups. The cognitive claims are the least tested part. Animal learning studies and imaging changes are a reasonable basis for interest, and a reason to run a proper trial. They are not yet evidence that a healthy adult will focus better.[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018)[4](https://www.vitalsvault.com/peptides/semax#source-gusev-2005)[6](https://www.vitalsvault.com/peptides/semax#source-lebedeva-2018)[8](https://www.vitalsvault.com/peptides/semax#source-asmarin-1997) ## Semax side effects and safety The safety record reads well on paper. Its developers reported that in their clinical experience Semax produced no negative side effects or complications, and the 2005 cerebrovascular study described a small share of side effects and good tolerability, including in older adults. The caution is about what was measured. Small studies are not built to catch uncommon problems, many reports did not describe safety in detail, and none of the studies cited here gives long-term data from outside Russia. FDA’s April 2026 compounding page noted limited safety information for the proposed routes of use. Two practical points follow from the mechanism. Because animal work suggests Semax can amplify stimulant effects on dopamine, anyone taking ADHD medication or other stimulants should raise it with a clinician. And stroke recovery is a medical process with its own care team, so Semax belongs in that conversation, never in place of it. Quality is the other risk. A prescription filled by a licensed compounding pharmacy is a different product from a vial labeled for research, and with a nasal peptide you are trusting the maker with something that goes directly onto a mucous membrane next to the brain.[8](https://www.vitalsvault.com/peptides/semax#source-asmarin-1997)[4](https://www.vitalsvault.com/peptides/semax#source-gusev-2005)[14](https://www.vitalsvault.com/peptides/semax#source-fda-bulks)[9](https://www.vitalsvault.com/peptides/semax#source-tsai-2007) ## Which labs matter before trying Semax Most people interested in Semax want sharper thinking, and the most useful labs are the ones that find common, fixable reasons for fog. HbA1c, your average blood sugar over about three months, can flag diabetes or prediabetes, though it does not capture day-to-day swings. Vitamin B12 matters because low levels cause memory slips and tiredness that no peptide will correct. ALT, a liver enzyme, and eGFR, a measure of kidney filtering, are general health context a clinician may want before a new prescription. They are not Semax-specific markers, and no study cited here sets a monitoring panel for Semax, but a baseline makes any later change easier to interpret. This is how Vitals Vault approaches peptide care. A blood panel at Quest Diagnostics comes first, a licensed clinician reviews your results and history and decides whether Semax fits, and the course ends with a retest of the same markers. The clinician sets the form and length of the course.[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006) ## Where Semax stands in 2026 On October 29, 2026, NCPA reported that FDA granted enforcement discretion allowing 503A compounding pharmacies to prepare Semax, and five other peptides, for individual patients with a prescription. There is no end date, and final rulemaking is still pending. Semax is still not an FDA-approved drug in the US, even though it is used as a medicine in Russia. No company has put it through the US trials an approval requires.[13](https://www.vitalsvault.com/peptides/semax#source-ncpa)[14](https://www.vitalsvault.com/peptides/semax#source-fda-bulks) ## What this means for you Semax is a stress-hormone fragment stripped of its hormone job, with real if mostly Russian human data in stroke and a consistent animal story built around BDNF. Its reputation as a focus peptide runs ahead of the human evidence for that use. The most useful thing the research teaches is that Semax works on a signal you already make. Exercise, sleep and early, hard rehabilitation move the same marker. So the question worth asking a clinician is what else might explain the fog or forgetfulness you notice, and whether the foundations are in place for any peptide to add something on top.[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018)[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006) Know your baseline before any peptide 120+ lab tests at Quest Diagnostics, every result reviewed by a licensed clinician. Most results in 3–5 business days. A baseline today gives your clinician something to compare against if you start Semax later. [Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans)[Get early access to peptide care](https://www.vitalsvault.com/peptides-waitlist) Full refund before your blood draw · No membership ## What to expect with Semax A responsible start looks like a health history, a baseline blood panel that rules out common causes of brain fog, and a clinician’s decision on whether Semax fits. The prescriber sets the strength, schedule and length of a course, and it ends with a retest. On timing, imaging studies show brain-network changes within 5 to 20 minutes of a nasal dose, and the developers described effects lasting most of a day. In stroke patients, blood BDNF rose during treatment and stayed high through the study. Whether you notice anything in daily thinking is the least studied part, so keep notes and judge it honestly.[6](https://www.vitalsvault.com/peptides/semax#source-lebedeva-2018)[8](https://www.vitalsvault.com/peptides/semax#source-asmarin-1997)[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018) ## Key Semax studies - Gusev et al., 1997[3](https://www.vitalsvault.com/peptides/semax#source-gusev-1997) Controlled clinical study · 30 people given Semax plus standard care vs 80 on standard care, acute ischaemic stroke Faster recovery of general and focal deficits, especially movement Limits: Randomization and blinding not described; small treated group - Gusev et al., 2005[4](https://www.vitalsvault.com/peptides/semax#source-gusev-2005) Clinical study · 187 people with chronic cerebrovascular insufficiency Clinical improvement, fewer strokes and transient ischaemic attacks, well tolerated Limits: Russian study by the developers’ network; design detail limited - Dolotov et al., 2006[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006) Animal study · Rats One nasal dose raised hippocampal BDNF up to 1.4 times and TrkB activation up to 1.6 times, with better learning Limits: Rats, not people - Medvedeva et al., 2014[7](https://www.vitalsvault.com/peptides/semax#source-medvedeva-2014) Genome-wide animal study · Rats after experimental stroke Over half of Semax-changed genes were immune genes; dozens of vessel genes shifted Limits: Gene expression, not outcomes - Gusev et al., 2018[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018) Clinical study, 2x2 groups · 110 people after ischaemic stroke Semax raised blood BDNF and went with faster daily-living recovery; without Semax, earlier rehab went with higher BDNF Limits: Randomization and blinding not described; one research network - Lebedeva et al., 2018[6](https://www.vitalsvault.com/peptides/semax#source-lebedeva-2018) Placebo-controlled imaging study · 24 healthy volunteers Changes in the brain’s default mode network within 20 minutes of a nasal dose Limits: Brain activity, not thinking performance Key studies on Semax | Study | Design | Who | What it found | Limits | | --- | --- | --- | --- | --- | | Gusev et al., 1997[3](https://www.vitalsvault.com/peptides/semax#source-gusev-1997) | Controlled clinical study | 30 people given Semax plus standard care vs 80 on standard care, acute ischaemic stroke | Faster recovery of general and focal deficits, especially movement | Randomization and blinding not described; small treated group | | Gusev et al., 2005[4](https://www.vitalsvault.com/peptides/semax#source-gusev-2005) | Clinical study | 187 people with chronic cerebrovascular insufficiency | Clinical improvement, fewer strokes and transient ischaemic attacks, well tolerated | Russian study by the developers’ network; design detail limited | | Dolotov et al., 2006[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006) | Animal study | Rats | One nasal dose raised hippocampal BDNF up to 1.4 times and TrkB activation up to 1.6 times, with better learning | Rats, not people | | Medvedeva et al., 2014[7](https://www.vitalsvault.com/peptides/semax#source-medvedeva-2014) | Genome-wide animal study | Rats after experimental stroke | Over half of Semax-changed genes were immune genes; dozens of vessel genes shifted | Gene expression, not outcomes | | Gusev et al., 2018[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018) | Clinical study, 2x2 groups | 110 people after ischaemic stroke | Semax raised blood BDNF and went with faster daily-living recovery; without Semax, earlier rehab went with higher BDNF | Randomization and blinding not described; one research network | | Lebedeva et al., 2018[6](https://www.vitalsvault.com/peptides/semax#source-lebedeva-2018) | Placebo-controlled imaging study | 24 healthy volunteers | Changes in the brain’s default mode network within 20 minutes of a nasal dose | Brain activity, not thinking performance | ## Semax myths and evidence - ### Semax is just ACTH, so it will raise cortisol Semax keeps a fragment of ACTH, but it was designed to drop the hormonal activity, and reviewers describe it as completely devoid of it. In rats, its studied effects run through BDNF and immune and vascular genes in the brain; how much of that explains effects in people is uncertain.[9](https://www.vitalsvault.com/peptides/semax#source-tsai-2007)[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006) - ### Semax has been proven to boost focus in healthy people Its developers reported better memory and attention under demanding conditions, and imaging studies show brain-network changes after a dose. None of the studies cited here is a large controlled trial of cognition in healthy adults.[8](https://www.vitalsvault.com/peptides/semax#source-asmarin-1997)[6](https://www.vitalsvault.com/peptides/semax#source-lebedeva-2018) - ### There is no human research on Semax There is a fair amount, mostly Russian: stroke studies from 1997 to 2018, a 187-person cerebrovascular study, an optic nerve study and imaging studies in volunteers. Its limits are size, design and independence.[3](https://www.vitalsvault.com/peptides/semax#source-gusev-1997)[4](https://www.vitalsvault.com/peptides/semax#source-gusev-2005)[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018)[5](https://www.vitalsvault.com/peptides/semax#source-polunin-2000) - ### If you take Semax you can skip the exercise In the 2018 stroke study, earlier rehabilitation went with higher BDNF even without Semax, and the authors credited both with better recovery. In healthy people, exercise is the best-documented everyday way to raise BDNF.[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018)[10](https://www.vitalsvault.com/peptides/semax#source-szuhany-2015) Know your baseline first 120+ lab tests at Quest, every result reviewed by a licensed clinician. Most results in 3–5 business days. [Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans) ## How is Semax taken? Semax is given into the nose, and the studies that name a form used nasal drops. A compounded US prescription can be prepared in a nasal form. Your prescriber sets the strength and schedule.[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006)[5](https://www.vitalsvault.com/peptides/semax#source-polunin-2000)[6](https://www.vitalsvault.com/peptides/semax#source-lebedeva-2018) ## Semax dosage There is no FDA-approved dose of Semax. In Russia it is a registered drug sold as nasal drops in two strengths. Human studies used single doses in healthy volunteers, short daily courses of drops for a few days, and higher daily doses in courses of 5 or 10 days after stroke; the doses studied are listed in the table on this page. Your clinician sets your dose.[11](https://www.vitalsvault.com/peptides/semax#source-fda-pcac-semax)[3](https://www.vitalsvault.com/peptides/semax#source-gusev-1997)[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018) ## Typical Semax dosage Semax is registered in Russia as nasal drops in two strengths. In people, healthy-volunteer studies gave a single nasal dose or a two-day course, other studies used drops three times a day for 10 days, and Russian stroke studies gave much higher daily doses in courses of 5 or 10 days. There is no FDA-approved dose, and your clinician sets any actual dose. These are reference doses from FDA labels, studies in people and clinical practice reports, shown for education. They are not a recommendation or a prescription. Your dose, form and schedule should be set by a licensed clinician who knows your history and lab results. Already have a prescribed dose? The [peptide dosage calculator](https://www.vitalsvault.com/peptides/tools/dosage-calculator) turns it into the units to draw on an insulin syringe. - Clinical practice report · Nasal drops 0.1% or 1% solution Not given in the FDA summary[11](https://www.vitalsvault.com/peptides/semax#source-fda-pcac-semax) Strengths of the drug registered in Russia, as summarized by FDA in July 2026 - Human trial · Into the nose 1.2 mg Single dose[6](https://www.vitalsvault.com/peptides/semax#source-lebedeva-2018)[11](https://www.vitalsvault.com/peptides/semax#source-fda-pcac-semax) 14 healthy adults in a brain-imaging study (dose as tabulated by FDA) - Human trial · Into the nose 1 mg (16 µg/kg), or 0.25 mg once Once daily for 2 days, or a single dose[11](https://www.vitalsvault.com/peptides/semax#source-fda-pcac-semax) 19 healthy adult men (Kaplan 1996, as summarized by FDA) - Human trial · Nasal drops, 1% solution 2 to 4 drops per nostril Three times a day for 10 days[11](https://www.vitalsvault.com/peptides/semax#source-fda-pcac-semax) 32 adults with peptic ulcer, added to standard ulcer treatment (Ivanikov 2002, as summarized by FDA) - Human trial · Not stated in the abstract 6,000 µg a day Daily, in two 10-day courses with a 20-day break between them[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018) Semax subgroups within a study of 110 adults in early (about 89 days) or late (about 214 days) rehabilitation after ischaemic stroke; each group had Semax and no-Semax subgroups - Human trial · Not stated in the abstract 12 mg a day (moderate stroke) or 18 mg a day (severe stroke) Daily; courses of 5 or 10 days (the abstract does not pair each course with a dose)[3](https://www.vitalsvault.com/peptides/semax#source-gusev-1997) 30 adults in the acute phase of ischaemic stroke, added to intensive standard care Typical Semax doses in people, by source | Source | Form | Amount | How often | Notes | | --- | --- | --- | --- | --- | | Clinical practice report[11](https://www.vitalsvault.com/peptides/semax#source-fda-pcac-semax) | Nasal drops | 0.1% or 1% solution | Not given in the FDA summary | Strengths of the drug registered in Russia, as summarized by FDA in July 2026 | | Human trial[6](https://www.vitalsvault.com/peptides/semax#source-lebedeva-2018)[11](https://www.vitalsvault.com/peptides/semax#source-fda-pcac-semax) | Into the nose | 1.2 mg | Single dose | 14 healthy adults in a brain-imaging study (dose as tabulated by FDA) | | Human trial[11](https://www.vitalsvault.com/peptides/semax#source-fda-pcac-semax) | Into the nose | 1 mg (16 µg/kg), or 0.25 mg once | Once daily for 2 days, or a single dose | 19 healthy adult men (Kaplan 1996, as summarized by FDA) | | Human trial[11](https://www.vitalsvault.com/peptides/semax#source-fda-pcac-semax) | Nasal drops, 1% solution | 2 to 4 drops per nostril | Three times a day for 10 days | 32 adults with peptic ulcer, added to standard ulcer treatment (Ivanikov 2002, as summarized by FDA) | | Human trial[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018) | Not stated in the abstract | 6,000 µg a day | Daily, in two 10-day courses with a 20-day break between them | Semax subgroups within a study of 110 adults in early (about 89 days) or late (about 214 days) rehabilitation after ischaemic stroke; each group had Semax and no-Semax subgroups | | Human trial[3](https://www.vitalsvault.com/peptides/semax#source-gusev-1997) | Not stated in the abstract | 12 mg a day (moderate stroke) or 18 mg a day (severe stroke) | Daily; courses of 5 or 10 days (the abstract does not pair each course with a dose) | 30 adults in the acute phase of ischaemic stroke, added to intensive standard care | ## Is Semax right for you? A clinician makes the call. These are the questions they will ask first. ### It may suit - Adults focused on focus, memory and cognitive performance under supervision - People who want common causes of brain fog ruled out with labs first ### Talk to a clinician first if you are - Recovering from a stroke (this belongs with your neurologist) - Taking medicine for a neurological or psychiatric condition, including stimulants - Pregnant or breastfeeding - Living with kidney or liver disease Vitals Vault peptide care starts with a blood panel and a licensed clinician, and ends with a retest. [Get early access to peptide care](https://www.vitalsvault.com/peptides-waitlist) ## BDNF is fertilizer for neurons Brain-derived neurotrophic factor, BDNF, helps neurons survive, grow and form new connections, especially in the memory center. Exercise reliably raises it: a 2015 meta-analysis of 29 studies in people found a moderate rise after a single session, and a larger one in people who trained regularly. In a 2018 stroke study, earlier rehabilitation went with higher blood BDNF too. The habits that make this signal come first, and a peptide would only add to them.[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006)[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018)[10](https://www.vitalsvault.com/peptides/semax#source-szuhany-2015) ### What else moves the same system 1. 01MoveExercise is the best-documented everyday way to raise BDNF in people. 2. 02Protect your sleepNo peptide replaces it. 3. 03Know your blood sugarUnrecognized diabetes or prediabetes is worth ruling out. HbA1c is the simple test. 4. 04Check your B12Low B12 causes memory slips and fog that no peptide will fix. ## Labs to check with Semax A blood test before you start and a retest after shows what actually changed for you. It is how Vitals Vault approaches every treatment. 1. TestA baseline panel at Quest Diagnostics. 2. DecideA licensed clinician reviews your history and results. 3. RetestThe same markers again, side by side. [Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans) - [Liver enzymes (ALT)Part of a metabolic panel. Checks the liver before and during any new prescription.](https://www.vitalsvault.com/biomarkers/alt) - [Kidney function (eGFR)Peptides are cleared through the kidneys, so a baseline is useful.](https://www.vitalsvault.com/biomarkers/egfr) - [HbA1cYour average blood sugar over about three months, which can flag diabetes or prediabetes. It does not capture short-term swings.](https://www.vitalsvault.com/biomarkers/hemoglobin-a1c) - [Vitamin B12Low B12 causes memory slips and fog that no peptide will fix.](https://www.vitalsvault.com/biomarkers/vitamin-b12) ## Is Semax FDA approved? No. Since October 29, 2026, FDA allows 503A pharmacies to compound Semax for individual patients with a prescription, under enforcement discretion, while the final rule is pending.[13](https://www.vitalsvault.com/peptides/semax#source-ncpa) [What FDA’s decision means](https://www.vitalsvault.com/peptides/fda-peptide-compounding-2026) ### Semax timeline 1. 1997 Developers review 15 years of Semax design and testing; Russian clinical study in acute ischaemic stroke.[8](https://www.vitalsvault.com/peptides/semax#source-asmarin-1997)[3](https://www.vitalsvault.com/peptides/semax#source-gusev-1997) 2. 2000 Study of Semax in optic nerve disease.[5](https://www.vitalsvault.com/peptides/semax#source-polunin-2000) 3. 2005 Study of 187 people with chronic cerebrovascular insufficiency.[4](https://www.vitalsvault.com/peptides/semax#source-gusev-2005) 4. 2006 Semax shown to raise BDNF and TrkB in the rat hippocampus.[1](https://www.vitalsvault.com/peptides/semax#source-dolotov-2006) 5. 2014 Genome-wide study shows Semax shifts immune and vascular genes after experimental stroke.[7](https://www.vitalsvault.com/peptides/semax#source-medvedeva-2014) 6. 2018 Stroke study links Semax and early rehabilitation to higher BDNF; brain-network imaging study.[2](https://www.vitalsvault.com/peptides/semax#source-gusev-2018)[6](https://www.vitalsvault.com/peptides/semax#source-lebedeva-2018) 7. April 2026 FDA’s compounding safety page lists Semax as a nominated bulk substance and notes how little human safety data exists.[14](https://www.vitalsvault.com/peptides/semax#source-fda-bulks) 8. July 2026 FDA’s Pharmacy Compounding Advisory Committee votes to recommend adding Semax to the 503A bulks list.[13](https://www.vitalsvault.com/peptides/semax#source-ncpa) 9. October 29, 2026 FDA grants enforcement discretion, so 503A pharmacies can compound Semax with a prescription. No end date; final rule pending.[13](https://www.vitalsvault.com/peptides/semax#source-ncpa) ![A Filipino man, 35, round face, clean shaven, short black hair, wool cap looks up from a book in a cabin](https://www.vitalsvault.com/_next/image?url=%2Fpublic-v3%2Fshoot%2Fpeptides%2Ffaq-semax.webp&w=3840&q=75&dpl=shadow-production-f0162cb4d465-40992538108-1) ## Semax questions What is Semax used for? In Russia, Semax is used for ischaemic stroke and some neurological and eye conditions. Elsewhere it is studied and used for focus, memory and nerve protection. It is not FDA-approved for any condition. What are the benefits of Semax? Russian studies report better stroke recovery, higher BDNF levels and fewer flare-ups of cerebrovascular disease. Its developers reported better memory and attention in healthy men under demanding conditions, and in rats Semax raised BDNF and improved learning. How does Semax work? In rats it raises BDNF, a protein that helps brain cells grow and connect, and activates its receptor, TrkB. After experimental stroke in rats it also shifts immune and blood-vessel genes, which its researchers think may help protect brain tissue. How much of this carries over to people is not settled. What is the difference between Semax and Selank? Both are Russian nasal peptides with the same Pro-Gly-Pro tail. Semax comes from ACTH and is studied for stroke, memory and focus. Selank comes from tuftsin, an immune peptide, and is studied for anxiety. Selank is not part of FDA’s October 2026 policy. Is Semax a nasal spray? It is given into the nose. A 2000 optic nerve study used nasal drops, and a 2018 brain-imaging study in healthy volunteers gave it intranasally. A compounded prescription is prepared in a nasal form your prescriber chooses. What are the side effects of Semax? Published studies have not reported significant side effects, and a 2005 study described it as well tolerated, including in older adults. Long-term data from outside Russia are limited. What is the Semax dosage? There is no FDA-approved dose. In Russia, Semax is sold as nasal drops in two strengths. Studies in people ranged from a single nasal dose in healthy volunteers to drops three times a day for 10 days, with higher daily doses in courses of 5 or 10 days in Russian stroke studies. The doses studied are listed in the dosage table on this page. Your clinician sets your dose. Does Semax affect stress hormones? No. Semax comes from a fragment of ACTH, the hormone that drives cortisol, but it was designed to keep the brain effects without the hormonal ones and has no hormonal activity. Is Semax FDA approved? No. Semax is not FDA-approved for any use. Since October 29, 2026, FDA allows 503A compounding pharmacies to prepare it for individual patients with a prescription, under enforcement discretion, while final rulemaking is pending. Is Semax legal in the US? A licensed prescriber can now order compounded Semax from a 503A pharmacy for a specific patient. Vials sold online as "research use only" are not made for people and are not covered by FDA’s October 2026 policy. Can I get Semax through Vitals Vault? Vitals Vault is opening clinician-led peptide care that starts with a blood test. Join the peptides waitlist to hear first. A licensed clinician reviews your history and labs and decides whether Semax is right for you. ## Peptides, prescribed and measured Vitals Vault is opening peptide care that starts with your blood work, is prescribed by licensed US clinicians and ends with a retest. Join the waitlist to hear first. - Prescription only - Licensed US clinicians - Quest Diagnostics labs [Get early access to peptide care](https://www.vitalsvault.com/peptides-waitlist)[Start with 120+ lab tests · $99](https://www.vitalsvault.com/labs#plans) ## Keep reading [Full Peptide Guide](https://www.vitalsvault.com/peptides) - EpitalonA four-amino-acid pineal peptide studied for telomeres, melatonin and healthy aging. - KPVA three-amino-acid piece of the hormone alpha-MSH, studied for calming gut and skin inflammation. - FDA peptide update 2026What FDA’s October 2026 decision on six peptides means for you. - CerebrolysinA mixture of peptides and amino acids from pig brain, used in some countries for stroke and dementia, with weak evidence in Cochrane reviews. - DihexaA lab-made angiotensin IV analogue studied in animals for memory, with no human trials and a retracted mechanism paper. ## Sources 1. 1. [Dolotov OV, et al. Semax regulates BDNF and trkB expression in the rat hippocampus. Brain Res. 2006 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/16996037/) 2. 2. [Gusev EI, et al. The efficacy of Semax in patients at different stages of ischaemic stroke. Zh Nevrol Psikhiatr Im S S Korsakova. 2018 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/29798983/) 3. 3. [Gusev EI, et al. Effectiveness of Semax in the acute period of hemispheric ischaemic stroke. Zh Nevrol Psikhiatr Im S S Korsakova. 1997 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/11517472/) 4. 4. [Gusev EI, et al. Semax in prevention of disease progress in cerebrovascular insufficiency. Zh Nevrol Psikhiatr Im S S Korsakova. 2005 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/15792140/) 5. 5. [Polunin GS, et al. Therapeutic effect of Semax in optic nerve disease. Vestn Oftalmol. 2000 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/10741256/) 6. 6. [Lebedeva IS, et al. Effects of Semax on the default mode network of the brain. Bull Exp Biol Med. 2018 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/30225715/) 7. 7. [Medvedeva EV, et al. The peptide semax affects the expression of genes related to the immune and vascular systems in rat brain focal ischemia: genome-wide transcriptional analysis. BMC Genomics. 2014 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/24661604/) 8. 8. [Asmarin IP, et al. A nootropic adrenocorticotropin analog 4-10-semax (15 years experience in its design and study). Zh Vyssh Nerv Deiat Im I P Pavlova. 1997 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/9173745/) 9. 9. [Tsai SJ. Semax, an analogue of adrenocorticotropin (4-10), is a potential agent for the treatment of attention-deficit hyperactivity disorder and Rett syndrome. Med Hypotheses. 2007 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/16996699/) 10. 10. [Szuhany KL, et al. A meta-analytic review of the effects of exercise on brain-derived neurotrophic factor. J Psychiatr Res. 2015 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/25455510/) 11. 11. [FDA. Briefing document, Pharmacy Compounding Advisory Committee meeting, July 23 to 24, 2026: Semax-related bulk drug substances (opens in a new tab)](https://www.fda.gov/media/193348/download) 12. 12. [Panikratova YR, et al. Functional connectomic approach to studying Selank and Semax effects. Dokl Biol Sci. 2020 (opens in a new tab)](https://pubmed.ncbi.nlm.nih.gov/32342318/) 13. 13. [NCPA. FDA grants enforcement discretion for compounding six peptides. October 29, 2026 (opens in a new tab)](https://ncpa.org/newsroom/qam/2026/10/29/fda-grants-enforcement-discretion-compounding-six-peptides) 14. 14. [FDA. Certain bulk drug substances for use in compounding that may present significant safety risks (current as of April 22, 2026) (opens in a new tab)](https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks) 15. 15. [FDA. Bulk drug substances used in compounding under section 503A (opens in a new tab)](https://www.fda.gov/drugs/human-drug-compounding/bulk-drug-substances-used-compounding-under-section-503a-fdc-act) Written by the Vitals Vault editorial team, medically reviewed by Robert Lufkin, MD, and updated October 29, 2026. This is general education, not medical advice. None of these peptides is FDA-approved to diagnose, treat, cure or prevent any disease, and compounded medicines are not FDA-reviewed for safety, effectiveness or quality. 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