Compound record · Cognition, mood & sleep
Semax
Also Семакс · ACTH(4-7)-PGP · Met-Glu-His-Phe-Pro-Gly-Pro · N-acetyl Semax · NA-Semax
Synthetic ACTH-fragment heptapeptide
Russian intranasal 'nootropic' peptide; stroke data unreplicated abroad
Record reviewed 1 September 2026 · 4 references
- Class
- Synthetic ACTH(4-10) analogue (heptapeptide)
- Route
- Intranasal drops or spray
- Human trials
- Russian open-label studies; largest stroke study 30 treated vs 80 controls
- Authorised
- Russia only (stroke, cognitive impairment); not UK, US, EU, AU or CA
- WADA
- Not on the Prohibited List
01 Overview
What Semax is
Summary
Semax is a synthetic heptapeptide derived from the adrenocorticotropic hormone fragment ACTH(4-10), designed to retain nootropic activity without hormonal effects. It is registered in Russia as 0.1% and 1% nasal drops for acute ischaemic stroke, cognitive impairment and optic nerve disease. Outside Russia it has no authorisation; the supporting trials are Russian, largely open-label, and have not been replicated by independent groups.
Mechanism
Thought to act through melanocortin receptors and to increase expression of brain-derived neurotrophic factor (BDNF) and its receptor TrkB, with reported effects on cerebral blood flow, inflammation and neuronal survival in animal models. It has no corticotropic (cortisol-raising) activity.
02 Evidence by goal
What has been shown, for which goal
Grades follow one scale across the site. Limited overall means: small or short human studies, mixed results, or evidence mainly for a related use.
General wellbeing
LimitedSmall Russian studies report faster recovery after stroke and improved attention or memory scores in patients with cognitive impairment, plus a small healthy-volunteer study of attention. None were placebo-controlled to modern standards, and there are no trials of Semax for focus, mood or energy in healthy adults.
Longevity
InsufficientNeuroprotective effects in rodent models of ischaemia and neurodegeneration have not been tested as healthy-ageing or cognitive-decline prevention in humans.
03 Regulatory status
Where it is authorised, and for what
Status is recorded per jurisdiction from regulator sources and reviewed by hand. It is never inferred from another region's decision.
United Kingdom
Not authorisedNot authorised as a medicine; sold only as an unregulated 'research chemical'.
No MHRA marketing authorisation. Nasal sprays and vials sold online are unlicensed products.
04 Dosing research
What the evidence says about exposure
Published human studies and the doses, routes and durations they used — reported as research information, not a recommendation.
Research information — not a recommendation. These are the exposures used in published human studies, reported so you can see what has been tested. They are not dosing instructions and do not apply to any individual.
Study 01
Semax in the acute period of hemispheric ischaemic stroke
Gusev EI et al., Zh Nevrol Psikhiatr Im S S Korsakova 1997;97(6):26–34 · Source
- Design
- Open-label, non-randomised, controlled: 30 treated patients versus 80 matched controls on conventional therapy
- Population
- Adults in the acute phase of hemispheric ischaemic stroke, moderate or severe
- Participants
- n = 110
- Duration
- 5–10 days of treatment
- Route
- Intranasal
- Doses studied
- Semax 1% intranasal: 12 mg/day for moderate stroke, 18 mg/day for severe stroke, in divided doses
- Outcome at this exposure
- Faster regression of general cerebral and focal (especially motor) deficits on clinical rating scales versus controls, with EEG and evoked-potential changes. Not randomised or blinded; published only in Russian.
- Adverse events observed
- No adverse effects or deaths attributed to treatment were reported in the abstract; systematic safety reporting is absent.
Beyond the stroke study, Russian reports in cognitive impairment, optic nerve disease and healthy volunteers (0.1% solution, typically 200–600 µg per day) are small, mostly open-label and published in Russian; none has been independently replicated. Online 'nootropic' regimens using sprays of unknown concentration or 'N-acetyl' derivatives have no human data at all.
05 Safety
Adverse effects and contraindications
Common effects seen in trials or reports, serious effects that warrant urgent review, and conditions under which use is not appropriate or needs assessment.
Common adverse effects
- Nasal irritation or burning (intranasal use)
- Headache
- Restlessness, anxiety or agitation
- Difficulty sleeping if used late in the day
Serious adverse effects
- Worsening of anxiety or psychotic symptoms in susceptible people (label caution)
- Allergic or hypersensitivity reactions
- Unknown long-term effects — no controlled safety data beyond short courses
Contraindications
- Mental health conditionCaution
The Russian label lists acute psychosis and disorders accompanied by anxiety as contraindications; agitation and anxiety have been reported. Any mental-health history warrants professional review.
- Epilepsy or seizuresCaution
A history of seizures is listed as a contraindication on the Russian label; effects on seizure threshold have not been formally studied.
- High blood pressureCaution
Not studied in uncontrolled hypertension. Semax has no shown corticotropic activity, but some Russian sources advise caution because of its ACTH-fragment origin — a theoretical consideration.
Do not use = should not be used · Caution = needs assessment
06 Interactions
Medicine classes that need review
Grouped by how seriously the combination should be taken. Class labels match the medicines questionnaire in the assessment.
- Major
- Moderate
- Minor
Moderate
Monitoring or dose review is usually advised.
Stimulant
Methylphenidate, lisdexamfetamine
Interactions are unstudied. Semax is described as activating; combined with methylphenidate or amfetamine-type stimulants, additive agitation, insomnia or blood-pressure effects are plausible.
Antidepressant
Sertraline, fluoxetine, venlafaxine, mirtazapine
No interaction studies. Because Semax is proposed to alter BDNF and monoamine signalling, combination with antidepressants is unstudied and should be discussed with the prescriber.
07 Pregnancy & breastfeeding
Status in pregnancy
The Russian label lists pregnancy and breastfeeding as contraindications. There are no human safety data.
08 Monitoring
What is usually monitored
Parameters that trials and product information track. A clinician decides what applies to an individual.
- 01Mood, anxiety and sleep, particularly during the first days of use
- 02Blood pressure if there is a history of hypertension
- 03Seizure control where relevant
- 04Nasal symptoms with repeated intranasal use
- 05Objective measures of the cognitive outcome being targeted, ideally with a clinician
09 Combinations
What is known about combining it
Notes on pairing with other compounds in the directory: whether the combination has been studied in people, and where mechanisms overlap.
Selank
Limited human data
Overlap · Both are centrally acting Russian regulatory peptides administered intranasally.
Commonly co-used in Russia and in online 'nootropic stacks', but no trial has tested the combination. Effects on alertness may be additive or opposing (semax activating, selank calming).
DSIP
No human studies
No human data; the compounds are marketed for opposing purposes (daytime activation versus sleep), so stacking rationale is unclear.
BPC-157
No human studies
No human data on this combination; BPC-157 itself lacks human efficacy data.
CJC-1295
No human studies
No human studies of Semax combined with growth-hormone secretagogues.
Discuss any proposed combination with a qualified healthcare professional.
10 Source considerations
Supply, quality and legitimacy
How the compound reaches people in practice, and what that means for product quality.
- 01Outside Russia every product is an unregulated 'research chemical'; concentration, purity and stability of home-made sprays are unverified.
- 02Imported Russian nasal drops may be counterfeit and are unlicensed in the UK, US, EU, AU and CA.
- 03'N-acetyl Semax' and 'amidate' derivatives sold online are distinct molecules with no human data.
11 Questions for your clinician
Take these to your appointment
Specific to this compound. The personal assessment adds questions drawn from your own history and medicines.
- 01Is there any evidence that Semax improves focus or memory in someone without a neurological diagnosis?
- 02How would this interact with my current medicines, particularly stimulants or antidepressants?
- 03Given the activating effects reported, how should anxiety, sleep and blood pressure be monitored?
- 04What authorised options exist for the cognitive or mood symptoms I want to address?
- 05What is known about safety with use beyond the 5–10 day courses used in trials?
The personal assessment tailors this list to your responses.
12 References
Sources behind this record
Regulator documents and peer-reviewed publications used to derive every grade and statement above.
- 01Gusev EI et al. Effectiveness of Semax in acute hemispheric ischaemic stroke. Zh Nevrol Psikhiatr 1997
- 02Kaplan AY et al. Synthetic ACTH analogue Semax displays nootropic-like activity in humans. Neurosci Res Commun 1996;19:115–123
- 03FDA — Bulk drug substances that may present significant safety risks (503A Category 2)
- 04WADA 2026 Prohibited List
The Peptide Checkup provides educational information and a structured summary of published research and regulatory status. It is not medical advice, does not diagnose or treat any condition, and does not replace a consultation with a qualified healthcare professional.
Personal assessment
Check Semax against your history
Seven minutes of structured questions about your goal, history and medicines, mapped against this record by a deterministic, clinician-reviewable rules engine. The report tells you when not to buy.