Semax: Reference Overview and Reconstitution Notes

July 9, 2026

Semax

What it is

Semax is a synthetic heptapeptide derived from the ACTH(4-10) fragment of adrenocorticotropic hormone, with an added C-terminal Pro-Gly-Pro tail intended to improve its stability against enzymatic breakdown. It was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences and belongs to the family of short peptide fragments studied for effects on the nervous system.

Research context and categorization

Semax is generally grouped under the cognitive and neuroprotective (nootropic) research category. In laboratory settings it is commonly discussed in relation to neurotrophic signaling, and it has been investigated for its apparent influence on brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) expression in animal models. It is also studied in the context of cerebral ischemia models, neuronal survival, attention, and memory-related endpoints.

These uses are investigational. In the United States, Semax is not FDA-approved, and the neuroprotective, cognitive, or mood-related properties described in the research literature are not confirmed or approved outcomes. In Russia and some neighboring countries it has been registered as a pharmaceutical for indications such as ischemic stroke and cognitive impairment, but that foreign approval does not establish these uses as proven or approved elsewhere.

Status

Regulatory status: Research-only in the United States. Not FDA-approved. It has no U.S. drug approval or USP monograph, though it is approved and prescribed as a medication in Russia for certain indications.
Sport status: Not specifically listed by name on the WADA Prohibited List. However, as a non-approved substance it may fall under the S0 catch-all category (any pharmacological substance not addressed by another section of the list and with no current approval by any governmental regulatory health authority for human therapeutic use), which is prohibited at all times. Athletes should verify current status with their governing body, since classifications can change.

Reconstitution notes (general)

Semax typically ships as a lyophilized (freeze-dried) powder that is reconstituted with bacteriostatic water before use in research handling. The resulting concentration is straightforward: concentration equals the milligrams of peptide in the vial divided by the millilitres of bacteriostatic water added. For example, 5 mg in 5 mL gives 1 mg/mL. You can work out any combination with the calculator at our reconstitution and blend calculators.

Dilution and handling notes (compound-specific)

Semax is a short, highly water-soluble peptide that generally dissolves readily and forms a clear, colorless solution, without the gelling or cloudiness sometimes seen with larger or more hydrophobic peptides. A common reference range is 1 mL to 5 mL of bacteriostatic water per 5 mg vial, which spans roughly 5 mg/mL down to 1 mg/mL. Lower water volumes give a more concentrated solution and a smaller measured volume, while higher water volumes make small measurements easier to read. The exact water volume is chosen for measuring convenience rather than to overcome any solubility limit.

A practical handling point specific to short peptides like Semax: add the water slowly down the inside wall of the vial rather than aiming the stream directly onto the powder, and swirl gently instead of shaking. Direct high-velocity streams and vigorous shaking create shear and foaming that can promote peptide aggregation and degradation. If the powder does not fully dissolve at first, let the vial rest and swirl again rather than forcing it. If a properly reconstituted solution ever looks cloudy or shows floaters, that indicates a problem rather than normal behavior for this compound. Note that Semax is also encountered as a ready-to-use intranasal liquid; that presentation is already in solution and does not require reconstitution.

Handling and storage

Store reconstituted solution refrigerated at 2 to 8 degrees Celsius and keep it out of light. Wipe the rubber stopper with an alcohol swab before drawing, and label the vial with the mix date. A reconstituted, refrigerated solution is commonly referenced with an approximate 4-week window. Discard the vial if the contents become cloudy, discolored, or show visible floaters.

Tools and supplies

For laboratory and research reference only. Educational content, not medical, dosing, injection, or therapeutic guidance, and not intended for human or animal use. Any research uses described are investigational and not confirmed or approved benefits. Confirm anything involving health with a licensed professional. References linked above.