Semax
Also called ACTH(4-10) analogue; Met-Glu-His-Phe-Pro-Gly-Pro
A seven-amino-acid peptide derived from ACTH and used clinically in Russia. Evidence that it changes lab or brain-scan measures is stronger than evidence it improves everyday focus or treats ADHD.
Overview
What it is
A synthetic heptapeptide based on a fragment of adrenocorticotropic hormone. It is not an ACTH replacement.
How it works
In rats, it raised BDNF (a nerve-cell support protein) and its receptor TrkB in the hippocampus, along with changes in a learning task.
What the research shows
Small Russian brain-imaging studies in healthy volunteers found changes in resting-state brain networks, possibly with overlapping participants. A 2018 Russian study looked at stroke patients. None show reliable improvement in daily focus.
Studied for
- BDNF signalingrats
- Brain network activitysmall imaging studies
- Stroke recoveryRussian clinical use
Safety and regulatory status
Safety and side effects
FDA's 2026 review found inadequate intranasal safety information and no data for injection, and flags immune reactions from aggregation and impurities. One report described eye pain and burning after a nasal product. "No side effects" claims are not supported.
Regulatory status
Not a component of any FDA-approved drug (FDA, 2026). On FDA's list of compounding substances with potential safety risks.
Mixing and dosing reference
Reference information only. Read before using this section.
Semax Dosage (10 mg Vial) Protocol
- Vial
- 10 mg Semax
- Add diluent
- 5 mL or 10 mL measured nasal solution
- Concentration
- 2 mg/mL (5 mL) or 1 mg/mL (10 mL)
- 1 unit (U-100)
- 200 mcg (5 mL) or 100 mcg (10 mL) per 0.10 mL spray
- Route
- Intranasal
Semax 10 mg Nasal Spray Calculations
| Measured Final Volume | Vehicle Added After Transfer | Final Concentration | Per Verified 0.10 mL Spray |
|---|---|---|---|
| 5.0 mL | About 2.0 mL | 2,000 mcg/mL | 200 mcg50 nominal sprays |
| 10.0 mL | About 7.0 mL | 1,000 mcg/mL | 100 mcg100 nominal sprays |
Reference Schedule
| Period | Amount | Spray Volume | Frequency |
|---|---|---|---|
| Days 1–5 | 200–300 mcg per administration (400–900 mcg/day) | 0.20–0.30 mL at 1 mg/mL (2–3 verified 0.10 mL sprays) | 2–3 times in the first half of the day |
Research Amount to Spray Equivalents
| Research Amount | 5 mL Option200 mcg per Spray | 10 mL Option100 mcg per Spray |
|---|---|---|
| 200 mcg | 1 spray | 2 sprays |
| 300 mcg | 1.5 theoretical sprays | 3 sprays |
| 400 mcg | 2 sprays | 4 sprays |
| 500 mcg | 2.5 theoretical sprays | 5 sprays |
Published Human Intranasal Semax Dosage Research
| Source | Research setting | Published intranasal protocol |
|---|---|---|
| Kaplan et al., 1996 | Healthy-volunteer performance and EEG experiments | Experiments included 0.210 mg and 1 mg exposures; one operator experiment reported 1 mg in 0.4 mL physiological solution. |
| Lebedeva et al., 2018 | Healthy-volunteer functional MRI study | A single 1.2 mg exposure using a 1% solution, with 60 microliters placed into each nostril. |
| Gusev et al., 2018 | Condition-specific ischemic-stroke research | 6,000 mcg per day for 10 days, followed by a second 10-day course after a 20-day interval. |
| Nasution et al., 2013 | Moderate head-injury study with standard care | 9 mg on day 1, 6 mg on day 2, and 3 mg daily on days 3–5. |
| Peptic-ulcer study | Semax added to conventional therapy | A 1% solution, 2–4 drops three times daily for 10 days; the abstract does not establish a general-purpose protocol. |
| Motor-neuron-disease study | Open-label, condition-specific research | 12 mg per day in two 10-day courses separated by a two-week break. |
Core Formula
| Verified actuator output | 5 mL option2,000 mcg/mL | 10 mL option1,000 mcg/mL |
|---|---|---|
| 0.05 mL | 100 mcg | 50 mcg |
| 0.10 mL | 200 mcg | 100 mcg |
| 0.13 mL | 260 mcg | 130 mcg |
How to mix
- Add a small measured amount of sterile diluent to the vial and swirl gently until dissolved.
- Transfer the solution to a clean nasal spray bottle.
- Bring it to an exact measured final volume of 5 mL or 10 mL (see the chart above).
- Prime the pump and confirm it delivers 0.10 mL per full spray before use.
Protocol source: PeptideDosages.com
Common questions
Does Semax treat ADHD?
That has not been shown. ADHD has established treatments.
How quickly does it work?
Scan timing in studies is not a proven onset of better focus.
Is Semax the same as Selank?
No. They are different peptides.
Found in these blends
Related in Brain and Cognitive Health
Sources and further reading (5)
- Dolotov OV, et al. Semax regulates BDNF and TrkB in rat hippocampus. Brain Res, 2006.
- Effects of Semax on the default mode network. Bull Exp Biol Med, 2018.
- FDA. July 2026 Pharmacy Compounding Advisory Committee: Semax evaluation.
- NIMH. ADHD in adults.
- Source summary: PeptideDosages.com research overview (rewritten for NVO).
Laboratory research material: Semax Research Use Only