Emerging evidence · Grade B
Semax
Semax (ACTH 4-10 Analogue)
Score
64 / 100
Origin
Russia (ACTH 4-10)
Route
Intranasal
Status
Rx in Russia; investigational elsewhere
TL;DR
01
A synthetic analog of an ACTH fragment (4-10), developed in Russia and used there as an intranasal nootropic and neuroprotective agent for stroke and cognitive disorders.
02
It is approved and prescribed in Russia, but the clinical evidence base is almost entirely Russian and has not been replicated in large Western trials.
03
Its mechanism is plausible: in animals it raises BDNF and activates the trkB pathway involved in learning and neuroprotection.
04
For Western readers, the fair position is 'used clinically abroad, but under-evidenced by international standards' — it is not FDA- or EMA-approved.
05
Outside Russia it is sold as a research chemical with no purity or dosing guarantees.
Russian clinical use
Yes
stroke, cognition (approved)
Western RCTs
Limited
not independently replicated at scale
Mechanism
BDNF / trkB ↑
shown in animals
FDA / EMA
Not approved
no Western approval
Outside Russia
Research chemical
unregulated
Part 01 · How it works
Mechanism.
Semax is a short peptide based on a fragment of the hormone ACTH, engineered to be stable and given as a nasal spray. In Russia it's a prescribed nootropic used after stroke and for cognitive complaints. In animal studies it boosts BDNF — a growth factor important for learning and neuron survival — and activates its receptor trkB, which is a sensible mechanism for the effects claimed. The gap is evidence quality: the human trials are mostly Russian, smaller, and not replicated by large international studies, so Western regulators have not approved it.
A nasal-spray nudge to the brain's own growth-factor system. The biology is reasonable and it's prescribed in Russia — but by international evidence standards it's still unproven.
ACTH(4-10) analog
Met-Glu-His-Phe-Pro-Gly-Pro; a stabilized heptapeptide (added Pro-Gly-Pro) with melanocortin-derived neuroactivity but no corticosteroid effect.
BDNF/trkB modulation
Raises hippocampal BDNF and trkB activation in rodents, linked to learning and neuroprotection.
Intranasal delivery
Given as nasal drops/spray for direct CNS exposure; short-acting.
Evidence stage
Russian clinical use; mechanistic support from animal studies; limited international RCTs.
Part 02 · Dosing & administration
How it's taken.
Community-reported · unregulatedValues below reflect commonly reported community protocols for Semax. These are anecdotal and unregulated — not clinically validated and not a recommendation. Provided for educational purposes only — this is not medical advice and not instructions for self-administration. Consult your healthcare provider before making any health decision.
Standard dose
200-600 mcg
Intranasal (original Russian clinical route, 0.1%/1% solutions); subcutaneous used by some · 2–3x daily intranasal (SC: 2–3 days/week)
Duration
Course-based, days to weeks; SC often cycled 8 weeks on / 8 off
·
Russian use spans ~50–500 mcg/day for cognition and ~200–1000 mcg/day for stroke recovery; the 200–600 mcg range sits within this, but no dose is internationally standardized or FDA-labeled.
·
Analogue of ACTH(4-10) with a Pro-Gly-Pro extension; unlike full ACTH it has no mineralocorticoid/steroidogenic activity.
·
Outside Russia it is an unregulated research chemical with no purity/dose guarantee.
Need help with reconstitution?
Use the free peptide calculator for dilution, unit conversion, and injection volume.
Part 03 · Safety
Side effects, rare serious events, who shouldn't.
Common
Nasal irritation
From intranasal use.
Occasional
Headache
Transient, generally mild.
Occasional
Serious · rare
Long-term international safety
Extensive Russian use but limited independent long-term data.
Limited data
Product-quality risk
Research-chemical supply outside Russia may not match labeled purity/dose.
Source-dependent
Absolute · do not use
×
Pregnancy or breastfeeding
×
Children under 18
×
Known hypersensitivity to semax, ACTH fragments, or any component
×
Active seizure disorders (neuropeptide effects on CNS excitability)
×
Acute psychotic episodes (may modulate dopaminergic and serotonergic transmission)
Relative · discuss first
!
Pregnancy or breastfeeding — insufficient data
!
Reliance on it in place of proven stroke/cognitive care — evidence does not support that
!
Anyone needing internationally validated efficacy — it is not established
Interactions
Antidepressants (SSRIs, MAOIs)
Semax modulates BDNF and monoamine systems; may potentiate antidepressant effects
Moderate
Stimulants (amphetamines, methylphenidate)
Semax has mild stimulatory/nootropic effects; additive CNS stimulation
Minor
Anticonvulsants
Neurotrophic effects may alter seizure threshold; monitor seizure frequency
Moderate
Thyroid medications
ACTH-derived peptide may have theoretical effects on the hypothalamic-pituitary-adrenal/thyroid axis
Minor
Labs to monitor
CMP (Comprehensive Metabolic Panel)
Baseline and every 3 months
Liver and kidney function
CBC with Differential
Baseline and every 3 months
General safety monitoring
Cortisol (AM)
Baseline and at 4 weeks
ACTH-derived peptide — monitor adrenal function
ACTH Level
Baseline
Semax is ACTH 4-10 analogue; monitor for HPA effects
Part 04 · Evidence
How strong is the evidence?
64
Grade B
Grade B, Emerging. Semax has real clinical use in Russia and a plausible BDNF-based mechanism, but the international evidence base is thin — small, largely Russian trials without large-scale independent replication, and no Western approval.
Mechanistic plausibility
Coherent BDNF/trkB neuroprotective mechanism in animal work.
76
Human evidence
Clinical use and Russian trials exist; limited independent, international replication.
55
Safety & tolerability
Long clinical use in Russia with a benign short-term profile; long-term international data limited.
74
Durability
Short-acting; durability of cognitive benefit not established internationally.
58
Independence
Evidence concentrated in Russian institutions; sparse independent Western replication.
50
Part 05 · Research log
Every study we cite.
We list each study with its methodology, funding source, and our quality grade. Flagged studies aren't dismissed — they're tagged so you can weigh them.
01
2006
Brain Research Flagged
Semax regulates BDNF and trkB expression in the rat hippocampus
A single dose raised hippocampal BDNF protein and trkB activation and improved conditioned avoidance learning in rats — mechanistic support for its cognitive claims.
Rodent mechanistic study · Animal mechanism study; does not establish human efficacy.
PMID 16996037 ↗
Moderate (preclinical)
Evidence against
What didn't work, and where the evidence is thin.
Every publication is incentivized to tell you a peptide works. We catalogue the null results, failed trials, and mechanism limits we found in the same literature — so you can weigh them against the upside, with your provider.
01
Clinical evidence is largely Russian and under-replicated internationally
Mechanism limit international evidence base · 2006
Despite decades of use in Russia, semax lacks large, independent, international randomized trials; the mechanistic support is animal-based and the human evidence has not met Western regulatory standards.
What this means: Prescribed abroad is not the same as proven. For an international reader, semax should be treated as promising-but-unconfirmed, not established.
PMID 16996037 ↗
Part 06 · Cost & access
Where it's available, at what price.
Russia
Approved
Prescribed intranasal nootropic/neuroprotective agent.
Russian market
United States
Not approved
Not FDA-approved; sold as a research chemical.
Grey-market; unregulated
European Union
Not approved
Not approved; research-chemical only.
N/A
United Kingdom
Not approved
Not approved; research-chemical only.
N/A
The Peptide Column takes no affiliate commission from any source. Semax is prescribed in Russia but is not approved by the FDA or EMA; outside Russia it is an unregulated research chemical and its benefits are not established by international evidence. We link only to clinician-directed care, never to sellers.
Part 07 · Your appointment
Questions to bring.
01
What is the evidence quality from Russian clinical studies of Semax?
02
How does Semax compare to established nootropic or neuroprotective therapies?
03
Is intranasal Semax appropriate for my specific cognitive concerns?
04
Are there any interactions with stimulant medications or antidepressants?
References
Every citation, numbered.
Citation list. For our editorial read of each study — including bias flags and quality grades — see the Research log above.
- 01. Semax regulates BDNF and trkB expression in the rat hippocampus · Brain Research, 2006 · PMID 16996037 ↗
- 02. PubMed. Semax mechanistic and Russian clinical literature