Quick answer: the official Semax dosage in Russia is given in nasal drops: 2 to 3 drops per nostril (50 mcg per drop of the 0.1% product) two to four times a day, or 400 to 8,000 mcg a day, for 3 to 14 days.[1] The 1% product for acute stroke goes up to 20,000 mcg a day for 10 days.[2] Human studies used similar nasal doses, from about 1 mg once to 18 mg a day.[3][7] No human dose has been tested for injection, and Semax is not FDA-approved.
This guide lists the label doses, the doses used in each published human study, and what the gaps mean. For background on what Semax is and what the research shows, see our Semax profile and the nootropic peptides hub.
How Semax is dosed: drops, not milligrams
Semax is sold in Russia as nasal drops in two strengths. The labels state the dose per drop:[1][2]
| Product | Concentration | Amount per drop | Main use |
|---|---|---|---|
| Semax 0.1% | 1 mg per mL | 50 mcg | Cognitive problems, recovery after brain injury, mental fatigue, optic nerve disease, children 7+ |
| Semax 1% | 10 mg per mL | 500 mcg | Acute ischemic stroke only (adults) |
The 1% label counts 4 drops as 0.2 mL, so one drop is about 0.05 mL.[2] The 0.1% label says to put no more than 2 to 3 drops in each nostril at a time. When a bigger dose is needed, it is split into several applications 10 to 15 minutes apart.[1] That is why a single label dose of 2,000 mcg cannot be given in one go: 2 to 3 drops per nostril only delivers 200 to 300 mcg of the 0.1% product.
Both labels say the best dosing schedule is set by a doctor.[1][2]
Semax 0.1% dosage by use (Russian label)
| Use | Per-dose amount | Daily dose | Course |
|---|---|---|---|
| Memory and thinking problems from vascular brain disease, TIA | 200 to 2,000 mcg (3 to 30 mcg/kg) | 800 to 8,000 mcg, given 4 times a day | 10 to 14 days, repeatable |
| After head injury, neurosurgery or anesthesia | 1,400 to 3,500 mcg (40 to 50 mcg/kg), 3 times a day | — | 3 to 5 days, up to 14 |
| Mental fatigue, stressful or monotonous work | 2 to 3 drops per nostril, 2 to 3 times before midday | 400 to 900 mcg | 3 to 5 days, repeatable |
| Optic nerve disease | 2 to 3 drops per nostril, 2 to 3 times a day | 600 to 900 mcg | 7 to 10 days |
| Children 7+ with minimal brain dysfunction (including ADHD) | 1 to 2 drops per nostril (5 to 6 mcg/kg), morning and midday | 200 to 400 mcg | 30 days |
Source: Russian Semax 0.1% label.[1]
For optic nerve disease the label also describes giving Semax by nasal electrophoresis, a technique that uses a small electric current, at 400 to 600 mcg a day.[1]
Semax 1% dosage for acute stroke
The 1% product is only for the acute phase of moderate or severe ischemic stroke, alongside standard hospital treatment.[2]
| Stroke severity | Per dose | Times per day | Daily dose | Course |
|---|---|---|---|---|
| Moderate | 2 to 3 drops per nostril (2,000 to 3,000 mcg) | 3 to 4, every 3 to 4 hours | 6,000 to 12,000 mcg | 10 days |
| Severe | 3 to 4 drops per nostril (3,000 to 4,000 mcg) | 4 to 5, every 2.5 to 3 hours | 12,000 to 20,000 mcg | 10 days |
Source: Russian Semax 1% label.[2]
Doses used in human studies
Every published human study of Semax gave it into the nose, and almost all come from Russia.[7]
| Study | People | Dose | Duration |
|---|---|---|---|
| Acute stroke, 1997 | 30 on Semax vs 80 on standard care | 12 mg/day (moderate) or 18 mg/day (severe), judged most effective | 5 and 10-day courses[3] |
| Stroke rehabilitation, 2018 | 110 adults | 6,000 mcg/day | Two 10-day courses, 20 days apart[4] |
| Motor neuron disease (ALS), 2007 | 27 patients, open-label | 12 mg/day of the 1% product | Two 10-day courses, 2 weeks apart[5] |
| Peptic ulcer, 2002 | 32 adults with hard-to-heal ulcers (per FDA) | 2 to 4 drops of 1% per nostril, 3 times a day | 10 days[6][7] |
| Healthy volunteers, brain scans, 2018 | 14 on Semax, 10 on placebo | One dose of 1% (1.2 mg per FDA’s summary) | Single dose[8][7] |
| Healthy men (summarized by FDA) | 19 | 1 mg a day for 2 days, or 0.25 mg once | 1 to 2 days[7] |
A few points stand out:
- Doses varied widely. They ranged from a quarter of a milligram once to 18 mg a day, with no study comparing doses head to head in a randomized way.
- The stroke doses match the 1% label. The 1997 study’s 12 and 18 mg figures fall inside the 1% label’s 6,000 to 20,000 mcg daily range.[2][3]
- Results were modest and hard to pin down. The 1997 stroke study reported some faster recovery, especially of movement problems, but it was not randomized.[3] The ALS study found no change in disease scores, only better quality of life.[5] The ulcer study reported healing in 89.5% of Semax patients by day 14 versus 30.8% of controls, with Semax added to standard ulcer drugs.[6]
- One study reported a dose-related caution. In 73 patients with brain injury after oxygen loss, some had bursts of abnormal EEG activity after a dose, and the authors advised giving the first dose with brain-wave monitoring. The abstract does not give the dose used.[9]
Why animal doses don’t translate
Much of the Semax research online cites rat studies. In one, a single nasal dose of 50 mcg per kg raised the brain growth factor BDNF in the rat hippocampus about 1.4-fold.[10] Scaling a rat dose to a person by body weight is not a reliable way to choose a human dose, and the Russian labels use their own per-kg ranges for specific conditions.[1] If you need to convert micrograms to drops or milliliters for a dose your clinician has set, our peptide dosage calculation guide and calculator explain the math.
Injectable Semax: no human dose exists
Semax products marketed in the US include injectables and nasal sprays at strengths such as 2.5 mg per mL for injection and 1.25 mg per mL for spray, and some are sold “for research purposes only.”[7] FDA found:
- no published studies of Semax given by injection under the skin,
- no safety data for that route, and
- concerns about immune reactions from impurities and clumping (aggregation) of the peptide in injected products.[7]
FDA also lists Semax among bulk substances that may pose safety risks in compounding.[11] In July 2026, an FDA advisory committee voted 8 to 5 to recommend allowing Semax in pharmacy compounding, against FDA staff advice. FDA has not issued a final decision.[7][12] Until then, any “Semax injection dosage chart” online is not based on human studies.
Who should not use Semax
The Russian labels list these contraindications:[1][2]
- acute psychiatric conditions
- disorders accompanied by anxiety
- a history of seizures
- pregnancy and breastfeeding
- children under 7 (0.1%), or under 18 for eye and neurosurgical uses and for the 1% product
- allergy to any ingredient
The labels also advise against using decongestant nasal sprays that narrow blood vessels at the same time, because Semax is absorbed through the nose.[1] For side effects in more detail, see Semax side effects. For how the drops compare with sprays sold online, see Semax nasal spray.
Questions to ask your clinician
- Is there an approved treatment with stronger evidence for my problem, such as stroke rehabilitation, an ADHD medicine or a migraine preventive?
- Do I have any of the label’s contraindications, such as anxiety or seizures?
- If we did consider Semax, how would we know the product contains what it says?
- What would tell us it is working, and when would we stop?
A clinician should set any dose. Semax is not FDA-approved, and the doses here describe what was studied or labeled in Russia, not a treatment plan.
