Semax
ACTH(4-7)-Pro-Gly-Pro heptapeptide
ACTH-derived heptapeptide with intranasal human studies in neurologic settings, but limited modern-quality evidence and no FDA-approved U.S. indication.
Reference dose
200–600 mcg daily
Source-specific educational reference, not an individualized recommendation.
Reference schedule
Daily · 2 weeks
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Profiles include evidence, formats, units, source-specific reference amounts and, where relevant, device details. If any of those terms are unfamiliar, do not guess your way through them. Start with a Personalised Guide and we will put the foundations in the right order for you.
At a glance
Structure
ACTH-derived heptapeptide
Commonly described as ACTH(4-7)-Pro-Gly-Pro.
Human evidence
Intranasal studies
Mostly older/regional neurologic and mechanistic literature.
U.S. status
Not FDA approved
FDA reviewed Semax-related bulk substances in 2026.
SC safety data
Not identified by FDA
FDA found human literature primarily for intranasal administration.
What it is
Semax is a synthetic seven-amino-acid peptide derived from the ACTH(4-7) sequence with a Pro-Gly-Pro extension.
It is commonly described as a nootropic or neuroprotective peptide and has been studied mainly through intranasal administration in neurologic research.
Research focus
How it works
Semax is a synthetic ACTH(4-7)-related heptapeptide studied for neurotrophic, gene-expression and neuroprotective effects. Human literature is predominantly intranasal and comes largely from older or region-specific neurologic studies rather than large modern international trials.
Important context
Semax has human exposure and clinical literature, so classifying it as purely preclinical is too dismissive. However, FDA's 2026 compounding review concluded that the evidence was insufficient to support the nominated uses it evaluated and that human safety remained inadequately characterized.
What it is studied for
Stroke and ischemia research examines neuroprotection, recovery and inflammatory responses after brain injury.
Cognitive research explores neurotrophic signalling, attention, memory and functional connectivity.
Mechanistic work examines gene expression, BDNF-related pathways, peptidase activity and inflammatory signalling.
More contextHuman studies exist, but evidence quality and route matterSee the deeper context, evidence details and practical distinctions behind this profile.
Published human research includes ischemic-stroke and cerebrovascular studies plus small mechanistic fMRI experiments. Many clinical papers are older, Russian-language or have design/reporting limitations.
FDA's 2026 review found no published human pharmacokinetic studies and no published subcutaneous safety studies; the human safety evidence it identified was intranasal.
- Semax is registered as an intranasal drug in Russia, according to FDA's 2026 briefing review.
- A 1997 controlled clinical study in acute ischemic stroke involved 30 Semax-treated patients and an 80-patient conventional-therapy comparison group.
- A small 2018 placebo-controlled fMRI study evaluated acute intranasal Semax effects in healthy volunteers.
- FDA concluded in July 2026 that evidence was insufficient for cerebral ischemia, migraine and trigeminal neuralgia in the 503A compounding evaluation.
Why people are interested
What makes Semax worth researching.
Limited human clinical literature
Stroke / cerebrovascular research
Older clinical studies reported neurologic or rehabilitation signals after intranasal Semax, but trial design and reporting are less rigorous than modern large pivotal programmes.
Human biomarker + preclinical
Neurotrophic signalling
Human and preclinical studies have examined BDNF and other neurotrophic or inflammatory pathways as possible mediators of Semax effects.
Small human mechanistic study
Functional connectivity
Small placebo-controlled fMRI studies in healthy volunteers reported acute changes in resting-state brain connectivity after Semax.
Regulatory evidence review
FDA evidence assessment
In 2026 FDA concluded there was insufficient evidence to support the nominated cerebral ischemia, migraine and trigeminal-neuralgia uses for compounding-list inclusion.
Evidence
Where the evidence is strongest, and what kind of evidence it is.
Human · older controlled study
Acute ischemic stroke
A 1997 study reported faster neurologic recovery in 30 Semax-treated patients compared with an 80-patient conventional-therapy control group, but modern randomized reporting standards were limited.
Human · observational/comparative
Stroke rehabilitation
A later 110-patient rehabilitation study reported higher BDNF and faster functional improvement in Semax-treated subgroups, but the design does not provide the certainty of a blinded pivotal trial.
Human · small mechanistic
Healthy-volunteer fMRI
A placebo comparison in 24 healthy volunteers reported changes in default-mode-network measures after intranasal Semax.
Evidence judged insufficient
FDA 2026 review
FDA found no human pharmacokinetic studies, insufficiently characterized safety and insufficient effectiveness evidence for the nominated serious neurologic uses.
Human research
Human Semax literature exists, but much of it is older, relatively small and published in Russian-language neurologic journals.
Clinical studies in stroke and cerebrovascular disease have reported favorable neurologic or functional outcomes, but FDA's 2026 review found the available evidence insufficient for the nominated U.S. compounding uses.
Small healthy-volunteer neuroimaging studies demonstrate acute brain-network effects but do not establish meaningful clinical cognitive enhancement.
Preclinical research
Animal and laboratory studies report neuroprotective, anti-ischemic, neurotrophic and gene-expression effects across multiple experimental systems.
Mechanistic findings are broader and more numerous than the high-quality human clinical evidence.
Reference dosing
Reference amount, schedule and conversion.
A reference amount is only useful when you know the formulation, concentration and delivery device it belongs to. Do not transfer a vial amount into a pen, a pen click count into another pen, or a syringe-unit number into a different concentration.
01
Identify the format
Vial, reusable cartridge pen, prefilled multi-dose pen or single-dose autoinjector.
02
Confirm concentration
Know the total peptide amount and liquid volume or the manufacturer/vendor concentration.
03
Understand the units
Keep mg/mcg, mL and syringe units or device clicks separate.
04
Then use the reference
Only convert a known reference amount with the calculator that matches the actual device.
Source-specific reference
200–600 mcg daily
Daily · 2 weeks
The 200–600 mcg daily range is a Pep Report research reference. Published human regimens vary by indication and formulation.
Calculator connection
This profile does not currently use a vial or pen calculator. Follow the formulation-specific information shown for the product or reference you are using.
The clinically discussed route in the human literature is predominantly intranasal. The generic vial calculator is disabled because it could imply support for subcutaneous dosing even though FDA found no published SC safety studies.
Storage
Start with the format. Then verify the exact product.
Rule of thumb, not a product instruction
Storage belongs to the exact formulation. Generic advice can orient you, but the label, pharmacy directions or formulation-specific stability data should determine the final temperature and usable-life limits.
Pens
Treat a pen as a finished drug-device product: protect it from unnecessary heat and light, do not freeze unless the exact label explicitly permits it, and use that device's own unopened and in-use storage window.
Vials
Treat dry and reconstituted vials as different stability states. Refrigeration after mixing is common for some formulations but is not a universal peptide rule.
Product-specific notes
There is no FDA-approved U.S. Semax product label establishing standardized storage or device requirements.
Intranasal product performance depends on concentration, container, pump/dropper characteristics and formulation stability.
Practical reference
Formats
Intranasal drops/spray in published human literature
Research injection products are also marketed
Reconstitution & units
The human literature identified by FDA is predominantly intranasal rather than subcutaneous.
This profile therefore does not provide a vial-reconstitution pathway for injected Semax.
Published studies use different concentrations and study-specific regimens, so there is no single universal dose to translate into drops or syringe units.
The generic vial calculator is intentionally disabled to avoid implying validated injected dosing.
Safety, status & open questionsOpen the practical cautionsSemax is not FDA approved in the United States. It has human intranasal research and regional clinical use, but the evidence base does not meet the standard of a modern FDA-approved neurologic medicine.
Open questions
No FDA-approved dose or U.S. indication exists.
FDA reported no published human pharmacokinetic studies and no published subcutaneous safety data.
Many efficacy claims online extend far beyond the conditions and outcomes studied in the available human literature.
Evidence from intranasal administration cannot automatically validate injected Semax products.
Regulatory notes
Semax is not FDA approved in the United States.
FDA's July 2026 compounding review concluded that the evidence weighed against inclusion of Semax-related bulk substances on the 503A Bulks List for the uses evaluated.
FDA's briefing states that Semax is registered in Russia and available there as intranasal drops, illustrating that regulatory status differs by jurisdiction.
Practical notes
FDA states that the human intranasal safety profile is insufficiently characterized and that there are no published subcutaneous safety data.
FDA notes potential immunogenicity concerns for compounded Semax related to aggregation and peptide impurities.
The FDA review identified a consumer FAERS report involving persistent ocular pain/burning after an online Semax nasal product; a single report cannot establish causation but is a relevant safety signal.
FDA also noted a theoretical bleeding concern based on reported antithrombotic effects in one reference, particularly in people with other bleeding risks.
Common mistakes
Calling Semax purely preclinical despite published human intranasal studies.
Treating regional registration or use as equivalent to FDA approval.
Using small neuroimaging studies as proof of meaningful cognitive enhancement.
Assuming intranasal evidence validates subcutaneous research products.
Presenting one online nootropic dose as a universal clinically established regimen.
Common questions
Does Semax have human studies?
Yes. There are human intranasal studies in stroke, cerebrovascular disease and healthy volunteers, but the evidence is relatively small, region-specific and not equivalent to a modern FDA approval programme.
Is Semax FDA approved?
No. FDA reviewed Semax-related bulk substances in 2026 and found the evidence insufficient for the nominated serious neurologic uses.
Why is there no vial calculator?
Because the identified human literature is predominantly intranasal and FDA found no published subcutaneous safety studies. A vial calculator would imply support for a route that is not clinically established.
Does an fMRI change prove Semax improves cognition?
No. Functional-connectivity changes show a measurable acute brain effect, but they do not by themselves establish a meaningful cognitive or clinical benefit.
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References