Semax
Synthetic nootropic peptide developed in Russia in the 1980s, derived from the ACTH(4-10) fragment with the addition of the Pro-Gly-Pro (PGP) tripeptide at the C-terminus to increase stability. Approved in Russia and some CIS countries for clinical use in neurological conditions, including ischemic stroke and cognitive dysfunction. Administered intranasally, Semax is one of the few nootropic peptides with substantial clinical data — although most comes from Russian studies not replicated in the West.
Last updated:: 13/04/2026
Research Status
ANVISA (Brazil)
Not regulated
FDA (USA)
Not regulated
EMA (Europe)
Not regulated
Mechanism of Action
Semax acts through multiple neuroprotective mechanisms. It modulates the melanocortinergic system through MC3 and MC4 receptors, increasing BDNF (brain-derived neurotrophic factor) and NGF (nerve growth factor) expression in the hippocampus and cortex. The increase in BDNF promotes synaptic plasticity, neurogenesis, and neuronal survival. Additionally, Semax inhibits enzymes involved in enkephalin degradation (DPPIV and others), prolonging the action of endogenous opioid peptides that modulate mood and pain. The PGP fragment confers anti-inflammatory activity by inhibiting neutrophil migration. In the context of stroke, it reduces oxidative stress, inhibits the inflammatory cascade, and reduces the ischemic penumbra area.
Study Protocols
Dosages and regimens used in published clinical studies. This does not constitute a medical prescription.
Cognição / neuroproteção
IntranasalSpray nasal, solução 1%. Ciclos de 10–14 dias com pausa.
Protocolo hospitalar aprovado na Rússia
Análogo sintético do ACTH(4-10). Aprovado na Rússia como nootrópico e neuroprotetor. Aumenta BDNF, modula dopamina e serotonina. Não aprovado no Ocidente. Par do Selank (ansiolítico) — frequentemente usados em combinação.
Benefits
Cognitive improvement
ProvenRussian clinical trials demonstrated improvements in attention, memory, and processing speed in patients with mild cognitive dysfunction and in healthy volunteers. Approved in Russia as a nootropic since the 1990s.
Neuroprotection after stroke
ProvenClinical studies in Russia showed that Semax administered intranasally within the first hours after ischemic stroke reduced neurological deficit and improved functional recovery. It is approved as adjunct stroke treatment in Russia.
BDNF increase
ProvenMultiple studies have demonstrated that Semax significantly increases BDNF levels and its TrkB receptors in the brain, one of the central mechanisms behind its nootropic and neuroprotective effects.
Anxiety reduction
Under researchPreclinical studies and clinical reports suggest a mild anxiolytic effect, possibly mediated by melanocortinergic and opioidergic system modulation. Robust clinical data are still limited for this specific indication.
Risks and Side Effects
Nasal irritation
Low(10-15% of patients)Being administered intranasally, it may cause local irritation, dryness, or nasal discomfort. Generally mild and transient.
Headache
Low(5-10% of patients)Mild headaches have been reported by some users, especially at the start of use. They tend to resolve with continued treatment.
Theoretical risk of hair loss
Low(Rare/Theoretical)As an ACTH analog, there is a theoretical concern about effects on the hypothalamic-pituitary-adrenal axis that could affect the hair cycle. In practice, reports are rare and not confirmed in controlled studies.
Internet vs. Science
What people say online compared to the actual scientific evidence.
Semax is the most potent nootropic available
Partially trueWhat they claim
Semax drastically increases IQ, memory, and focus, being superior to any other nootropic on the market.
Actual evidence
Russian clinical trials show modest but statistically significant improvements in attention and memory. It is not a 'dramatic intelligence enhancer'. The effects are more evident in people with pre-existing cognitive deficits. In healthy individuals, improvements are subtle.
Semax has no side effects
Partially trueWhat they claim
It is completely safe and has no adverse effects, and can be used indefinitely.
Actual evidence
The safety profile is indeed favorable in the available studies, with generally mild side effects (nasal irritation, headache). However, the absence of long-term studies (> 1 year) and the lack of replication of Russian data in independent Western studies mean that long-term safety is not fully established.
Semax cures ADHD and depression
FalseWhat they claim
It can replace ADHD medications and antidepressants because it is more natural and has no side effects.
Actual evidence
No controlled clinical trials demonstrate Semax efficacy for ADHD or depression as a primary treatment. Some mechanisms (increased BDNF, dopaminergic modulation) are relevant to these conditions, but this does not constitute clinical evidence. It should not replace established treatments.
It's approved as a medication, so it's safe for anyone
Partially trueWhat they claim
Since it's approved in Russia, it has been thoroughly tested and is safe for anyone to use.
Actual evidence
Regulatory approval in Russia followed different standards than those required by the FDA, EMA, or ANVISA. Many Russian Semax studies have not been internationally replicated and are not available in English with detailed methodology. Approval in one country does not guarantee universal safety — that is why it is not approved in the West.
| Claim | O que dizem | Evidência real | Verdict |
|---|---|---|---|
| Semax is the most potent nootropic available | Semax drastically increases IQ, memory, and focus, being superior to any other nootropic on the market. | Russian clinical trials show modest but statistically significant improvements in attention and memory. It is not a 'dramatic intelligence enhancer'. The effects are more evident in people with pre-existing cognitive deficits. In healthy individuals, improvements are subtle. | Partially true |
| Semax has no side effects | It is completely safe and has no adverse effects, and can be used indefinitely. | The safety profile is indeed favorable in the available studies, with generally mild side effects (nasal irritation, headache). However, the absence of long-term studies (> 1 year) and the lack of replication of Russian data in independent Western studies mean that long-term safety is not fully established. | Partially true |
| Semax cures ADHD and depression | It can replace ADHD medications and antidepressants because it is more natural and has no side effects. | No controlled clinical trials demonstrate Semax efficacy for ADHD or depression as a primary treatment. Some mechanisms (increased BDNF, dopaminergic modulation) are relevant to these conditions, but this does not constitute clinical evidence. It should not replace established treatments. | False |
| It's approved as a medication, so it's safe for anyone | Since it's approved in Russia, it has been thoroughly tested and is safe for anyone to use. | Regulatory approval in Russia followed different standards than those required by the FDA, EMA, or ANVISA. Many Russian Semax studies have not been internationally replicated and are not available in English with detailed methodology. Approval in one country does not guarantee universal safety — that is why it is not approved in the West. | Partially true |
Studies and References (3)
Dolotov OV, Karpenko EA, Inozemtseva LS, et al. — Brain Research (2006)
Demonstrou que o Semax aumenta significativamente a expressão de BDNF e do receptor TrkB no hipocampo de ratos, fornecendo base mecanística para seus efeitos nootrópicos. O aumento de BDNF foi dose-dependente e persistiu por várias horas após administração.
PubMedGusev EI, Skvortsova VI, Izykenova GA, et al. — Bulletin of Experimental Biology and Medicine (2005) — n=60
Estudo clínico russo que avaliou Semax intranasal em pacientes com AVC isquêmico agudo. Os pacientes tratados com Semax apresentaram recuperação neurológica significativamente melhor e redução nos marcadores de dano cerebral em comparação ao grupo controle.
PubMedEremin KO, Kudrin VS, Saransaari P, et al. — Doklady Biological Sciences (2004)
Avaliou diferentes vias de administração do Semax e confirmou efeitos nootrópicos e analgésicos em modelos animais. A via intranasal demonstrou biodisponibilidade cerebral superior, justificando a formulação nasal adotada clinicamente na Rússia.
PubMedFrequently Asked Questions
How is Semax administered?
Semax is administered intranasally (nasal drops or spray). The most common formulation is the 1% (0.1%) solution. In the approved Russian protocol, the typical dose is 200-600 mcg per day, divided into 2-3 nasal applications. The intranasal route allows the peptide to reach the brain directly through the olfactory mucosa, avoiding gastrointestinal degradation.
Is Semax approved by ANVISA or the FDA?
No. Semax is approved only in Russia and some Commonwealth of Independent States (CIS) countries. It does not have FDA (US), EMA (Europe), or ANVISA (Brazil) approval. The clinical studies supporting its Russian approval have not been replicated under Western regulatory standards.
How long does it take to feel the effects of Semax?
According to clinical reports and user accounts, acute effects (improved focus and attention) can be perceived within 15-30 minutes after intranasal administration. Long-term effects on neuroprotection and synaptic plasticity require consistent use for weeks. Important: these reports come predominantly from Russian literature and biohacking communities, not from controlled Western studies.
Can I combine Semax with other nootropics?
There are no controlled studies on Semax interactions with other nootropics or psychoactive medications. Theoretically, the increase in BDNF and dopaminergic modulation may interact with antidepressants (especially SSRIs), stimulants, and other nootropics. Consult a physician before combining neuroactive substances.
Why isn't Semax approved in the West if it works in Russia?
Regulatory standards differ significantly. The FDA and EMA require multicenter, randomized, double-blind phase 3 clinical trials with large samples. Many Russian Semax studies have small samples, are not published in high-impact international journals, and do not follow all ICH-GCP criteria. To obtain Western approval, Semax would need new expensive clinical trials, and no Western pharmaceutical company has funded these studies to date.
Important notice
This content is strictly informational and educational, based on published scientific research. It does not constitute medical advice, prescription, or encouragement to use any substance. Always consult a qualified physician before starting any treatment.
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