Semax
PeptideThe community rates Semax substantially higher than the medical evidence base warrants [c1, c2 vs. s4, s10]. The medical rating reflects the lack of Western, independently replicated RCTs and the absence of long-term safety data [s5, s10, s11], while the community subjectively reports consistent cognitive improvements that have not yet been sufficiently confirmed in controlled studies.
Unlock full information
Dosages, side effects, studies and more — free after registration.
Register for freeRating Scales
TL;DR
Semax is a Russian research peptide with a compelling proposed mechanism — BDNF/NGF upregulation, dopaminergic modulation — but its evidence base consists almost entirely of Russian studies and animal data that have never been independently replicated in the West. Community reports on focus, mood, and memory are consistently positive but anecdotal; whether intranasal Semax actually crosses the blood-brain barrier in humans remains scientifically unresolved. In Germany, Semax is an unapproved research chemical, and importing it for personal use sits in a tight legal grey zone. For those who proceed anyway: HPLC-verified sources, low starting doses, and no continuous long-term use.
Description
Synthetic ACTH(4-7)-derived heptapeptide with BDNF/NGF upregulation, approved in Russia for stroke; research chemical outside Russia [s1, s3].
Semax is a synthetic heptapeptide consisting of the ACTH(4–7) fragment (Met-Glu-His-Phe) with a C-terminal Pro-Gly-Pro tripeptide that confers metabolic stability [s1, s2]. It was developed in Russia and has been approved there since 1994 by the Russian Ministry of Health as an intranasal drug (1% spray) for the treatment of acute ischemic stroke and other neurological conditions [s3, s5]. Following intranasal administration, the peptide crosses the blood-brain barrier and exerts its primary effects through rapid upregulation of BDNF (Brain-Derived Neurotrophic Factor) and NGF (Nerve Growth Factor) as well as their receptors in the hippocampus and prefrontal cortex [s6, s7, s8]. This mechanism fundamentally distinguishes Semax from classical stimulants or small-molecule nootropics. Clinical evidence derives predominantly from Russian and Ukrainian studies. A randomized trial in 100 patients with acute ischemic stroke demonstrated that intranasal Semax (12 mg/day for 5 days) accelerated neurological recovery compared to placebo [s4]. Preclinical studies demonstrate neuroprotective effects in ischemia-reperfusion models and improved cognitive performance in animal models [s2, s8, s9]. Outside Russia, Semax is traded primarily as a research chemical and holds neither FDA nor EMA approval [s5, s10]. Western long-term safety data beyond 30 days do not exist [s11]. In the biohacking community it is used for its cognitive and mood-enhancing effects, though the evidence base for these indications is largely anecdotal [c1, c2].
Legal Status (DE)
In Germany, Semax is not approved as a medicinal product and is not marketable as a dietary supplement. Under the AMG (German Medicines Act) it is classified as an unapproved medicinal product or research chemical. Import for personal use is legally very restricted; §73 AMG does not apply, as Semax is not marketable in any EU pharmacy. In Russia, Semax has been approved as a medicinal product (1% nasal spray) since 1994. Comparable restrictions to those in Germany apply in Austria and Switzerland. Semax is not listed on the anti-doping schedule of the German AntiDopG.
Mechanism of Action
Semax exerts its effects via several complementary mechanisms [s6, s7, s8]: 1. BDNF/NGF upregulation: Semax rapidly induces transcription of Bdnf, Ngf and their receptor TrkB in the hippocampus and frontal cortex via CREB phosphorylation — the same signaling pathway activated by exercise and antidepressants [s7, s8]. In rat models, BDNF levels were significantly elevated as early as 90 minutes post-administration [s9]. 2. Monoaminergic modulation: Semax modulates dopaminergic and serotonergic signaling pathways, which may contribute to improved mood and cognitive acceleration [s1, s3]. 3. Enkephalinase inhibition: Semax inhibits the enzyme enkephalinase (neprilysin), which degrades endogenous opioid peptides in the synaptic cleft. This prolonged availability of endogenous opioids is fundamentally distinct from exogenous opioid receptor agonism [s11]. 4. Melanocortin activity: As Semax is structurally derived from ACTH, it possesses weak melanocortin activity. On a theoretical basis, this could lead to increases in cortisol and blood pressure with chronic use; Russian clinical data at registered doses show virtually no such effect [s11]. 5. Neuroprotection: In ischemia-reperfusion models, Semax reduces infarct size and improves functional outcomes through activation of neuroprotective transcriptional programs [s2, s8]. The intranasal route enables direct transport along the olfactory nerve to bypass the blood-brain barrier, although the precise transport mechanism for a heptapeptide of this size remains scientifically debated [c1].
Dosing
Kognitive Verbesserung / Nootropikum
- Dose
- 200–600 mcg per dose
- Frequency
- 1–2× täglich
- Route
- intranasal
- Duration
- 14 Tage on, 14 Tage off (Zyklusprotokoll)
- Timing
- Morning and midday if needed; afternoon doses may impair sleep
- With food
- optional
Akuter ischämischer Schlaganfall (russisches klinisches Protokoll)
- Dose
- 12 mg/day (1% nasal spray)
- Frequency
- Mehrfach täglich aufgeteilt
- Route
- intranasal
- Duration
- 5 Tage
- Timing
- Inpatient use under medical supervision
- With food
- optional
NA-Semax (acetylierte Form, höhere Potenz)
- Dose
- 100–300 mcg per dose
- Frequency
- 1–2× täglich
- Route
- intranasal
- Duration
- 14 Tage on, 14 Tage off
- Timing
- Morning preferred
- With food
- optional
There is no officially established upper limit for non-clinical use. Russian clinical protocols use up to 12 mg/day (inpatient setting). In the community, doses above 900 mcg/day are considered high-risk for self-experimentation. Western long-term safety data are entirely absent [s11].
Semax is not approved for human use outside Russia as a research chemical. The dosages stated here are derived from Russian clinical protocols and community reports, not from Western validated studies. Quality variance among research chemical suppliers is considerable; HPLC-verified sources (≥99% purity) are recommended [s11].
Calculate reconstitution, plan dosing, look up injection technique
Side Effects
| Side Effect | Frequency | Severity |
|---|---|---|
| Nasenschleimhaut-Verfärbung / nasale Reizung Observed in approximately 10% of intranasal users according to the ADDF summary. Explicable by direct mucosal contact [s12]. | gelegentlich | leicht |
| Überreizung, Unruhe, Angstgefühle Reported particularly at higher doses or in sensitive users. Likely mediated by dopaminergic/serotonergic stimulation [s11, s12]. | gelegentlich | leicht |
| Kopfschmerzen Listed as a possible adverse effect in community reports and clinical summaries [s12, c1]. | gelegentlich | leicht |
| Stimmungsschwankungen Modulation of dopamine and serotonin systems can trigger brief emotional fluctuations in some users [s11]. | gelegentlich | leicht |
| Vorübergehender Blutdruckanstieg Theoretically possible via melanocortin activity; reported at very high doses or in combination with stimulants. Russian clinical data at registered doses show this effect rarely [s11]. | selten | moderat |
| Erhöhter Blutzucker (bei Diabetikern) Isolated reports of elevated blood glucose in patients with diabetes mellitus. Mechanism unclear, possibly via ACTH-related glucocorticoid-like activity [s12]. | selten | moderat |
| Schlafstörungen bei Nachmittagsdosierung Semax has a duration of action of approximately 4–6 hours. Late dosing can cause difficulty falling asleep [c1]. | gelegentlich | leicht |
Contraindications
Semax increases BDNF, which may lower the seizure threshold in certain forms of epilepsy. Caution is warranted; no controlled data available [s1].
No reproductive toxicology studies available in humans. Western long-term safety data are entirely lacking [s11].
Dopaminergic modulation may worsen psychotic symptoms. No clinical data available in this patient population [s1, s11].
Reports of anxiogenic effects at higher doses; Semax may exacerbate existing anxiety in sensitive users [s11, s12].
Isolated reports of elevated blood glucose; close blood glucose monitoring required during use [s12].
Interactions
Synergistic
Selank (GABAergic anxiolytic) may attenuate the anxiogenic side effects of Semax, while Semax counterbalances the mild sedative effect of Selank. Combination widely used in the community; no controlled studies available [c2, c3].
Acetylated form with improved stability and potentially higher potency; lower doses (approx. 100–300 mcg) recommended compared to standard Semax [s12].
Semax increases BDNF and modulates neurotrophins, while citicoline enhances acetylcholine availability. The combination is used to support memory problems and brain fog. Anecdotal reports from the nootropics community describe synergistic cognitive effects.
Alpha-GPC as a potent choline source complements the neurotrophic effect of Semax by optimizing acetylcholine availability. The combination is used in cognitive nootropic stacks to support focus and memory.
The combination of Semax with BPC-157 is used for simultaneous cognitive optimization and neuroprotection as well as systemic inflammation regulation. BPC-157 complements the neurotrophic effects of Semax by promoting cellular repair mechanisms.
Dihexa is a potent allosteric modulator of HGF/c-Met with direct BDNF signaling amplification. In combination with Semax, potentially additive effects on synaptic plasticity and neurogenesis may arise.
Cerebrolysin provides peptide fragments that mimic natural growth factors, thereby creating an optimal environment for the BDNF activity of Semax. The combination is discussed for comprehensive neuroprotective support.
ALCAR supports acetylcholine biosynthesis and mitochondrial energy supply in the brain, which may complement the neurotrophic effects of Semax. The combination is used in the nootropics community for comprehensive cognitive support.
Caution
Additive central nervous system stimulation; increased risk of overstimulation, anxiety, and blood pressure elevation. Interaction space considered unmapped [s11].
Semax modulates serotonergic signaling pathways; interactions with serotonin reuptake inhibitors are pharmacodynamically plausible but clinically uncharacterized. To be classified as unmapped [s11].
Theoretical risk from dopaminergic/serotonergic modulation by Semax combined with MAO inhibition; no data available [s11].
Studies
Tier A — High Evidence
Outcome: Nootropic effects in healthy subjects
Effect Size: Improvement in cognitive parameters; details in original publication in Russian
Outcome: Neurological recovery in acute ischemic stroke
Effect Size: Significantly improved neurological recovery vs. placebo; exact effect size not fully reported in available sources
Tier B — Moderate Evidence
Outcome: Reduction of infarct size, activation of neuroprotective genes
Effect Size: Significant reduction of ischemic damage; BDNF/NGF/TrkB upregulation confirmed
Outcome: BDNF/NGF gene expression dynamics following Semax
Effect Size: BDNF significantly elevated 90 min post-administration in frontal cortex and hippocampus
Tier C — Low Evidence
Outcome: Conditioned avoidance responses (learning and memory test)
Effect Size: Significantly increased number of conditioned avoidance responses in Semax group
Community Evidence
Top reported benefits
- Improved focus and mental clarity (often within a few days)
- Enhanced memory performance and faster learning
- Mood improvement / positive mood effect
- Increased motivation and productivity
- Neuroprotective effect valued by long-term users
Top reported issues
- Overstimulation or anxiety at higher doses or in sensitive users
- Sleep problems with afternoon dosing
- Quality variance among research chemical suppliers
- Nasal irritation / discoloration of mucous membranes
- Onset of effect delayed by several days in some users
Considerable community skepticism regarding BBB penetration with intranasal administration of a heptapeptide [c1]. The legal grey area in Germany and other EU countries is underestimated by many users. Lack of Western long-term safety data and supplier quality variance are cited as the primary risks [c1, c2].
Scientific Sources
- Synthetic ACTH analog Semax displays nootropic-like activity in humans
Nesterova IV, Seredenin SB, et al. (1995). Neuroscience and Behavioral Physiology (Russian)BLink - Is Semax FDA Approved in the US? Regulatory Overview
Oath Research Editorial (2025). OathResearch.comDLink - Semax Dosing Guide: Intranasal Research Protocols, Safety and Interactions
Parahealth Editorial (2024). Parahealth.comDLink - Semax Peptide Dosing Guide: SubQ, Nasal Spray, Protocol & Safety (2026)
PeptideDosing Protocols Editorial (2026). PeptideDosing ProtocolsDLink - Peptide legal in Deutschland? Rechtslage 2026
Peptide Culture Editorial (2026). Peptide-Culture.comDLink - Brain Protein Expression Profile Confirms the Protective Effect of the ACTH(4–7)PGP Peptide (Semax) in a Rat Model of Cerebral Ischemia–Reperfusion
Dmitrieva VG, Stavchansky VV, Botsina AY, et al. (2021). International Journal of Molecular SciencesCPMID:34199266DOI - Semax Cognitive Vitality For Researchers
Alzheimer's Drug Discovery Foundation (2022). ADDF Cognitive VitalityBLink - Semax and Selank Inhibit the Enkephalin-Degrading Enzymes of Human Serum
Kost NV, Sokolov OYu, Gabaeva MV, Grivennikov IA, Andreeva LA, Myasoedov NF, Zozulya AA (2001). Russian Journal of Bioorganic ChemistryBPMID:11443939DOI - Kinetics of Semax Penetration into the Brain and Blood of Rats after Its Intranasal Administration
Shevchenko KV, Nagaev IYu, Alfeeva LYu, Andreeva LA, Kamensky AA, Levitskaya NG, Shevchenko VP, Grivennikov IA, Myasoedov NF (2006). Bioorganicheskaya Khimiya (Russian Journal of Bioorganic Chemistry)CLink - Novel Insights into the Protective Properties of ACTH(4-7)PGP (Semax) Peptide at the Transcriptome Level Following Cerebral Ischaemia–Reperfusion in Rats
Dmitrieva VG, Povarova OV, Skvortsova VI, et al. (2020). International Journal of Molecular SciencesCPMID:32630681DOI - Semax - Wikipedia
Wikipedia contributors (2024). WikipediaDLink - The efficacy of semax in the treatment of patients at different stages of ischemic stroke
Romanova GA, Shakova FM, Gudasheva TA, et al. (2006). Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova (Russian)APMID:16996699 - Semax: An ACTH(4-7)-Derived Heptapeptide - Regulatory and Clinical Overview
Superpower Health Editorial (2024). Superpower.comDLink - Semax and Pro-Gly-Pro Activate the Transcription of Neurotrophins and Their Receptor Genes after Cerebral Ischemia
Dmitrieva VG, Limborska SA, Dergunova LV, et al. (2024). International Journal of Molecular SciencesCDOI - Semax and Neuroplasticity: BDNF, NGF & Cognitive Enhancement Research
Proxiva Labs Editorial (2024). ProxivaLabs.comDLink - Comparison of the temporary dynamics of NGF and BDNF gene expression in rat hippocampus, frontal cortex, and retina under Semax action
Agapova TY, Agniullin YV, Silachev DN, et al. (2009). Doklady Biological SciencesCPMID:19662538DOI - Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus
Shadrina MI, Dolotov OV, Grivennikov IA, et al. (2006). Brain ResearchCPMID:16996037DOI
Community Sources
Storage
Unopened
Refrigerator (2–8°C), protected from light; frozen for long-term storage (up to –20°C).
Opened
Store opened nasal sprays refrigerated (2–8°C) and use within 30 days. Avoid contamination.
Notes
As a peptide, Semax is temperature-sensitive. Lyophilized powder is more stable than reconstituted solution. Request a quality COA (HPLC-verified, ≥99% purity) from the supplier, as purity variance among research chemical sources is considerable [s11].