Pinc PeptideThe girly peptide research blog

Semax · Dose evidence · updated 8 October 2026

Semax dosage: what studies actually used

The short answer

In Russia, semax is a prescription nose drop: the 1% label lists 6,000 to 12,000 µg a day for moderate stroke and 12,000 to 20,000 µg a day for severe stroke, for 10 days4. Human studies gave 600 µg a day of the 0.1% drops, 6,000 µg a day in two 10-day courses after stroke, and 12 or 18 mg a day in acute stroke156. Healthy volunteers got 0.25 to 1.0 mg, or a single dose that FDA lists as 1.2 mg78. FDA has not approved semax, found ‘insufficient evidence of effectiveness’ for the uses it reviewed and found no safety data for injection under the skin8.

Not dosing advice. This page reports doses that studies and approved labels used, with their sources. It does not recommend a dose, and we do not give mixing, injection or unit-conversion instructions. Gray-market vials often do not contain what their label says. How we report doses.

Every dose studied in people

StudyWhoPeopleDose and routeWhat happened
Dontsova 2013, comparison with standard treatment (randomization not described) Adults aged 40 to 65 with psoriasis and metabolic syndrome; 60 given semax, 58 standard treatment only 118 600 µg a day: 2 drops of the 0.1% solution in each nostril 3 times a day
Nose drops, added to standard psoriasis treatment · 10 days		 The psoriasis severity score (PASI) fell 61.5% with semax versus 41.3% with standard treatment alone at days 13 to 14, and 61% versus 29.6% 3 months after treatment1. The authors report that patients tolerated semax without complications1.
Gusev 2018, open comparison in stroke rehabilitation (groups described as random; no placebo or blinding reported) Adults in early or late rehabilitation after ischemic stroke 110 6,000 µg a day
Nose drops (1% solution), added to rehabilitation · Two 10-day courses, 20 days apart		 At 1 month, scores on the Barthel index, a 0 to 100 scale of everyday self-care, rose 21.6 versus 11.3 points with early rehabilitation and 14.8 versus 4.1 with late rehabilitation5. At 5 months only the late groups still differed (23.7 versus 18.7 points)5.
Gusev 1997, comparison with usual care (how patients were assigned is not stated) Adults in the acute phase of ischemic stroke; 30 given semax, 80 usual care 110 12 mg a day (moderate stroke) or 18 mg a day (severe stroke), reported as the most effective daily doses
Added to intensive care; route not stated in the English summary · 5 or 10 days		 The authors reported ‘some influence’ on the recovery of damaged functions, especially movement, but the English summary gives no figures6.
Panikratova 2020, placebo-controlled brain-scan study Healthy volunteers given semax, selank or placebo; 14 given semax, per FDA 52 One dose, listed by FDA as 1.2 mg
In the nose, per FDA (the English summary calls it an injection) · Single dose; scans before and 5 and 20 minutes after		 Semax and selank each changed connections between the right amygdala, a brain area involved in fear, and part of the right temporal lobe; no thinking or memory outcomes were reported9. FDA says the people given semax appear very similar to those in Lebedeva 2018, and that it is unclear whether they were the same people8.
Koroleva 1996, single-dose pain study with no control group or blinding (as summarized by FDA) Adults with migraine (12), typical trigeminal neuralgia (16) or dental plexalgia, which the authors class as a type of trigeminal neuralgia (9) 37 0.5 mg/kg once, per FDA
In the nose · Single dose		 Four of 12 people with migraine said their headache stopped 90 to 120 minutes after the dose and 8 reported weaker relief; the 16 with typical trigeminal neuralgia had no change, and pain resolved in 6 of 9 with dental plexalgia8. The authors reported no side effects8.
Ivanikov 2002, controlled comparison with standard ulcer drugs alone Adults with hard-to-heal peptic ulcers 32 2 to 4 drops of the 1% solution 3 times a day (per nostril, per FDA)
Nose drops, added to omeprazole and other ulcer drugs · 10 days		 Ulcers had healed by day 14 in 89.5% of patients given semax versus 30.8% of controls10. FDA notes the paper did not discuss side effects8.
Serdiuk 2007, open-label trial with no control group described Adults with motor neuron disease (ALS) 27 12 mg a day
Nose drops (1% solution) · Two 10-day courses, 2 weeks apart		 Semax did not change nerve-muscle (EMG) findings or ALS scores; quality-of-life scores improved, mainly emotional state and motivation11.
Lebedeva 2018, placebo-controlled brain-scan study (randomization not stated) Healthy volunteers; 14 given semax, 10 placebo 24 One dose of the 1% solution, listed by FDA as 1.2 mg
In the nose · Single dose; scans before and 5 and 20 minutes after		 The semax group showed a larger front part of the default mode network, a set of brain areas active at rest, than the placebo group; no thinking or memory tests were reported812.
Kaplan 1996, study in healthy men (the abstract mentions no placebo group) Healthy adult men 19 0.25 to 1.0 mg (about 4 to 16 µg/kg); per FDA, 1 mg a day for 2 days or 0.25 mg once
In the nose · One or two days		 The authors reported EEG (brain-wave) changes like those of nootropic drugs and better performance on operator tasks for 20 to 24 hours7. FDA notes the paper did not discuss side effects8.

Studies, animals and users: kept apart

Doses below are what studies used or what a label says. They are not advice, and gray-market products may not contain what their label says.

In human studies

Russian labels (nasal drops only). Semax 1% contains 500 µg per drop. For moderate stroke the label lists 2 to 3 drops per nostril 3 to 4 times a day (6,000 to 12,000 µg a day); for severe stroke, 3 to 4 drops per nostril 4 to 5 times a day (12,000 to 20,000 µg a day); courses last 10 days4. Semax 0.1% contains 50 µg per drop. For memory and thinking problems from blood-vessel disease of the brain it lists single doses of 200 to 2,000 µg and 800 to 8,000 µg a day for 10 to 14 days; to prevent mental fatigue, 400 to 900 µg a day for 3 to 5 days; and for children aged 7 and up with minimal brain dysfunction, 200 to 400 µg a day for 30 days14. Studies: 6,000 µg a day in two 10-day courses after stroke5; 12 or 18 mg a day for 5 to 10 days in acute stroke6; 12 mg a day in two 10-day courses in ALS11; 2 to 4 drops of the 1% solution 3 times a day (per nostril, per FDA) for 10 days in peptic ulcer810; 0.25 to 1.0 mg (about 4 to 16 µg/kg) in healthy men7; and single doses listed by FDA as 1.2 mg in brain-scan studies8. FDA found no human data for injection under the skin, and the nasal studies do not describe the devices used8.

In animal studies

As reported. Rats: nasal 50 or 250 µg/kg raised BDNF in the basal forebrain at 3 hours15; nasal 250 µg/kg at 15 minutes and 1 hour after an induced stroke, then daily for 6 more days, shrank the damage8; 100 µg/kg into the abdomen (intraperitoneal) in other stroke studies8; 1 mg/kg a day in the nose for 5 days raised anti-clotting and clot-dissolving activity8. Rodents: 1.5 to 500 µg/kg into the abdomen in pain tests8; 0.15 mg/kg into the abdomen raised a serotonin breakdown product and boosted amphetamine’s effects16. Mice: 3 mg/kg a day into the abdomen, 5 days a week for life, in a strain prone to breast tumors8.

What users report Anecdotal · not validated · not a recommendation

A nootropics review site (updated 5 September 2026) lists up to 750 to 1,000 µg a day as a nasal spray and 100 to 300 µg a day injected under the skin13.

Half-life and how it is taken

Half-life
No human value found; lab and animal figures range from minutes to over an hour817FDA found no study of how semax is absorbed, spread or cleared in people by any route8. In rats it is rapidly broken down, and its main breakdown product is Pro-Gly-Pro8. Very little reaches the brain: FDA cites peak brain levels of about 0.005% of an IV dose and 0.072% of a nasal dose (at 2 minutes) in rats, while the developers’ review gives 0.01% and 0.093%817. The developers’ review gives conflicting figures, a half-life ‘in the body of a few minutes’ and more than 1 hour in serum, and says effects last 20 to 24 hours after a single dose, which it links to active breakdown pieces17.
Routes
  • Nasal drops (Russia’s 0.1% and 1% products; every human study FDA found used the nose)
  • Nasal spray (sold by US clinics and online sellers; no human data found on these products)
  • Subcutaneous injection, under the skin (proposed for US compounding and sold online; no human data found)
  • Endonasal electrophoresis, a weak current that carries the drug into the nose lining (Russian eye studies and the 0.1% label)
  • Intraperitoneal (into the abdomen) or intravenous injection (animal studies only)

What the Russian product information says

We could not open Russia’s official State Register of Medicines (GRLS) as of 7 October 2026, so the label figures on this page come from two Russian drug references24. The Vidal pages are general descriptions of the active ingredient, updated on 17 and 18 March 2021, which say they ‘cannot be used’ to decide whether to use a particular medicine (our translation)414. They list both strengths as prescription medicines held by Peptogen, with registrations dated 26 March 2025 (0.1%) and 18 June 2025 (1%) and no end date414.

Besides the doses for memory problems, mental fatigue and children, the 0.1% description lists these courses14:

  • After head injury, brain surgery or anesthesia: 1,400 to 3,500 µg (40 to 50 µg/kg) 3 times a day for 3 to 5 days, extended to 14 days if needed14.
  • For optic nerve disease: 600 to 900 µg a day for 7 to 10 days14.
  • By endonasal electrophoresis, in which a weak electric current carries the drug in through the nose: 400 to 600 µg a day for 7 to 10 days14.

Both descriptions rule it out in acute mental disorders, anxiety disorders, a history of seizures and hypersensitivity, and in pregnancy and breastfeeding, where no clinical studies were done414. The 1% drops are not for anyone under 18; the 0.1% drops are not for children under 7, or for anyone under 18 when used for eye disease or in brain surgery414. Both list one side effect: mild irritation of the nose lining with long use414.

An older text, which the RLS drug encyclopedia says is based on official instructions the maker approved on 9 August 2008, differs in places2. It gives 500 to 5,000 µg a day for the 0.1% drops, daily for 3 to 5 days and up to 14 days if needed, allows children from age 5, and lists no age limit for the 1% drops2.

Dose figures that could not be checked

FDA’s 2026 review lists a 2002 meeting abstract (Cherkasova) in which an unknown number of people with chronic ischemic brain disease received 600 mg of semax a day in the nose for 10 days; FDA could not find a full published article8. That is far more than any daily dose on the Russian labels, the highest of which is 12,000 to 20,000 µg a day for severe stroke4. We could not open the abstract to check the figure.

Versions of the same work can disagree on the dose. The Russian text of the 2013 psoriasis study gives 600 µg a day, but its English summary says ‘600 mg / day’, and a 2015 paper by the same team, with the same group sizes, also says ‘600 mg/day’13.

The 0.5 mg/kg single dose in the 1996 pain study also comes only from FDA’s summary, because we could not open the original paper8.

Studies that did not report a dose

Several other Russian studies gave semax to people, but their English summaries give no dose18192021:

  • Gusev 2005: 187 people with long-term poor blood flow to the brain; the authors reported less disease progression, a lower risk of stroke and few side effects, with no figures in the summary18.
  • Polunin 2000: optic nerve disease, with semax given as nose drops or by electrophoresis through the nose, compared with a control group19.
  • Nazarova 2013: 114 people (228 eyes) aged 42 to 70 with diabetic eye disease, given 0.1% semax by electrophoresis or as drops, or standard treatment only20.
  • Alekseeva 1999: 73 people with brain damage after oxygen loss, 14 of them in a persistent vegetative state; some showed bursts of abnormal (paroxysmal) brain-wave activity after semax was given, and the authors advised monitoring brain activity during the first dose21.
  • Two meeting abstracts that FDA lists, in 120 children aged 12 to 14 with depression and 331 children with tics or Tourette syndrome, give no dose, and FDA could not see the full studies8.

What FDA found, and what is still missing

In its 2026 review for US compounding, FDA counted semax given in the nose to 33 to 47 healthy adults, 69 adults with medical conditions and 451 children in the references it reviewed for safety8. It found ‘insufficient evidence of effectiveness’ for cerebral ischemia (poor blood flow to the brain), migraine and trigeminal neuralgia, and ‘insufficient clinical information to characterize the clinical safety profile’8.

No semax trial was registered on ClinicalTrials.gov when it was searched on 7 October 202622. The 100 to 300 µg a day injected under the skin that a nootropics site lists comes from no human study, since FDA found none that used that route813.

What is sold may not be the studied drug. FDA says it has found several salts and derivatives, ‘including different active moieties’, sold under the same common name8. N-acetyl semax, a modified form sold online, is a different molecule that behaved differently in a lab study, and we found no human study of it2324. Of 5 semax samples Finnrick tested from 12 March to 9 September 2026, 2 passed, 1 failed and 2 were incomplete25.

Questions people ask

How much semax should I take?

No dose is established outside Russia’s own labels, and FDA found ‘insufficient evidence of effectiveness’ for the uses it reviewed8. The Russian labels set doses for specific conditions, and studies used daily doses such as 600 µg and 6,000 µg in the nose, and 12 or 18 mg in acute stroke145614. Semax is not an FDA-approved drug, and US pharmacies may not compound it82627.

What is the difference between Semax 0.1% and 1%?

They are two strengths of the same Russian prescription nose drop, with different uses414. In the Vidal descriptions, the 1% drops are only for the acute phase of moderate or severe ischemic stroke in adults4. The 0.1% drops cover memory and thinking problems from blood-vessel disease of the brain, recovery after stroke, head injury, brain surgery or anesthesia, mental fatigue and stress, optic nerve disease and, from age 7, minimal brain dysfunction including ADHD14.

How long can you take semax?

The 0.1% description gives courses from 3 to 5 days for mental fatigue up to 10 to 14 days for memory and thinking problems, repeatable if needed, and 30 days for children; the 1% drops are given for 10 days414. The studies that report a schedule gave semax for 10 days or less per course, in one or two courses1561011. Both Russian descriptions say long use can mildly irritate the nose lining414.

Can you inject semax?

The Russian medicine is a nose drop, and every human study FDA found used the nose4814. FDA says there are ‘no safety data’ for semax injected under the skin, the route proposed for US compounding8.

Go deeper

Sources

  1. 1Efficiency of using Semax in complex therapy of patients with psoriasis accompanied with metabolic syndrome (in Russian) Chelovek i ego zdorov’e (Man and His Health), via CyberLeninka, 2013. cyberleninka.ru
  2. 2Семакс (Semax) 0.1% and 1% nasal drops: description based on the official instructions approved in 2008 RLS drug encyclopedia (rlsnet.ru), 15 May 2026. rlsnet.ru
  3. 3Possible drug correction of lipid metabolism disturbances associated with metabolic syndrome in patients with psoriasis (in Russian) Eksperimental’naia i Klinicheskaia Farmakologiia, 2015. pubmed.ncbi.nlm.nih.gov
  4. 4Семакс (Semax) 1% nasal drops: instructions for use Vidal Russia drug reference, 18 Mar 2021. vidal.ru
  5. 5The efficacy of semax in the tretament of patients at different stages of ischemic stroke (in Russian) Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, 2018. pubmed.ncbi.nlm.nih.gov
  6. 6Effectiveness of semax in acute period of hemispheric ischemic stroke (a clinical and electrophysiological study) (in Russian) Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, 1997. pubmed.ncbi.nlm.nih.gov
  7. 7Synthetic ACTH analogue Semax displays nootropic-like activity in humans Neuroscience Research Communications, Sep 1996. doi.org
  8. 8FDA Evaluation of Semax-Related Bulk Drug Substances (Semax (Free Base) and Semax Acetate), PCAC briefing document U.S. Food and Drug Administration, 11 May 2026. fda.gov
  9. 9Functional Connectomic Approach to Studying Selank and Semax Effects Doklady Biological Sciences, Jan 2020. pubmed.ncbi.nlm.nih.gov
  10. 10Therapy of peptic ulcer with semax peptide Bulletin of Experimental Biology and Medicine, Jul 2002. pubmed.ncbi.nlm.nih.gov
  11. 11The study of chronic partial denervation and quality of life in patients with motor neuron disease treated with semax (in Russian) Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, 2007. pubmed.ncbi.nlm.nih.gov
  12. 12Effects of Semax on the Default Mode Network of the Brain Bulletin of Experimental Biology and Medicine, Sep 2018. pubmed.ncbi.nlm.nih.gov
  13. 13Semax Nootropics Expert, 5 Sep 2026. nootropicsexpert.com
  14. 14Семакс (Semax) 0.1% nasal drops: instructions for use Vidal Russia drug reference, 17 Mar 2021. vidal.ru
  15. 15Semax, an analogue of adrenocorticotropin (4-10), binds specifically and increases levels of brain-derived neurotrophic factor protein in rat basal forebrain Journal of Neurochemistry, Apr 2006. pubmed.ncbi.nlm.nih.gov
  16. 16Semax, an ACTH(4-10) analogue with nootropic properties, activates dopaminergic and serotoninergic brain systems in rodents Neurochemical Research, Dec 2005. pubmed.ncbi.nlm.nih.gov
  17. 17A New Generation of Drugs: Synthetic Peptides Based on Natural Regulatory Peptides Neuroscience & Medicine (Scientific Research Publishing), Dec 2013. scirp.org
  18. 18Semax in prevention of disease progress and development of exacerbations in patients with cerebrovascular insufficiency (in Russian) Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, 2005. pubmed.ncbi.nlm.nih.gov
  19. 19Evaluation of therapeutic effect of new Russian drug semax in optic nerve disease (in Russian) Vestnik Oftalmologii, Jan 2000. pubmed.ncbi.nlm.nih.gov
  20. 20The results of the application of the pre-formed physical factors and neuroprotective therapy for the rehabilitative treatment of the patients with diabetic retinopathy (in Russian) Voprosy Kurortologii, Fizioterapii, i Lechebnoi Fizicheskoi Kultury, Sep 2013. pubmed.ncbi.nlm.nih.gov
  21. 21Use of semax at a follow-up of patients with posthypoxic encephalopathy (in Russian) Anesteziologiia i Reanimatologiia, Jan 1999. pubmed.ncbi.nlm.nih.gov
  22. 22ClinicalTrials.gov search for ‘semax’ (0 studies) ClinicalTrials.gov, accessed 7 Oct 2026. clinicaltrials.gov
  23. 23N-Acetyl Semax Peptide for Sale (25mg) Core Peptides (vendor), accessed 5 Oct 2026. corepeptides.com (seller page, deliberately not linked)
  24. 24Influence of the N-terminus acetylation of Semax, a synthetic analog of ACTH(4-10), on copper(II) and zinc(II) coordination and biological properties Journal of Inorganic Biochemistry, Nov 2016. pubmed.ncbi.nlm.nih.gov
  25. 25Semax Safety Testing Results & Vendor Ratings Finnrick, 9 Sep 2026. finnrick.com
  26. 26Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act (categories list) U.S. Food and Drug Administration, 14 May 2026. fda.gov
  27. 27Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks U.S. Food and Drug Administration, 22 Apr 2026. fda.gov

Not medical advice. Talk to a licensed clinician before using any drug. Report an error.