Semax is a synthetic peptide developed in Russia, structurally an analogue of a short fragment of adrenocorticotropic hormone (ACTH). It has been studied for neuroprotective and nootropic effects, mostly in rats and in small human brain-imaging studies run by Russian research groups. It is not approved by the US FDA or the European Medicines Agency for any use. No reliable human half-life has been published.
By Tessaro Pty Ltd, the maker of Pepti · Last reviewed
This page is a reference, not a protocol. It sets out what the published research on Semax actually shows — and how little of it is large or human — what can be said about its half-life, and what a clean log holds. It contains no dose figures and no schedule; a section below explains why that is deliberate, not an omission.
| Property | Value |
|---|---|
| Class / type | Synthetic peptide; a melanocortin derivative — the ACTH(4-7) fragment extended with a Pro-Gly-Pro tail (ACTH(4-7)PGP) (Filippenkov et al., 2020) |
| Origin | Developed in Russia; its originators are based at the Institute of Molecular Genetics (Filippenkov et al., 2021) |
| Route in studies | Intranasal in the published human work (Lebedeva et al., 2018); parenteral in some studies |
| Evidence base | Small Russian studies — mostly rat models [animal], plus small brain-imaging studies in healthy volunteers [human] (Filippenkov et al., 2020; Lebedeva et al., 2018; Panikratova et al., 2020) |
| Half-life | No reliable human half-life has been published. |
| Regulatory status | Not approved by the US FDA or the European Medicines Agency (EMA) for any indication (Mavrych et al., 2026) |
Semax is a synthetic peptide developed in Russia, where its originators are based at the Institute of Molecular Genetics (Filippenkov et al., 2021). Structurally it is an analogue of a short fragment of adrenocorticotropic hormone (ACTH): the ACTH(4-7) sequence with a Pro-Gly-Pro tail, which the literature labels ACTH(4-7)PGP and groups with the melanocortin derivatives (Filippenkov et al., 2020). It is studied for neuroprotective and nootropic effects, not for hormonal action.
Most of the mechanistic evidence is preclinical and comes from rats. In a transient middle cerebral artery occlusion model of stroke, Semax shifted brain gene expression after ischaemia-reperfusion, suppressing inflammation-related genes and activating neurotransmission-related genes (Filippenkov et al., 2020) [animal]. A separate rat study reported that it blunted the behavioural effects of acute stress and corrected stress-disrupted gene expression in the hippocampus (Filippenkov et al., 2021) [animal]. The authors of the first study note that the molecular mechanisms in the brain are not yet fully understood.
Human evidence exists but is thin. A small brain-imaging study in healthy volunteers found a measurable change in the brain’s default-mode network after intranasal Semax versus placebo (Lebedeva et al., 2018) [human], and a related study reported functional-connectivity effects for both Semax and the related peptide Selank in a few dozen participants (Panikratova et al., 2020) [human]. These are small, mostly single-centre Russian studies measuring brain-imaging signals, not clinical trials measuring health outcomes.
Two points stand out. The evidence base is small and concentrated in Russian groups, and the animal work far outweighs the human. And Semax is not an approved medicine: a review of therapeutic peptides places it among non-approved agents with promising preclinical but only limited clinical evidence and no long-term safety data (Mavrych et al., 2026), and it is not approved by the US FDA or the European Medicines Agency for any use.
No reliable human half-life has been published. The pharmacokinetic picture for Semax comes from preclinical and laboratory work rather than from human studies, and a review lists dosing and monitoring among the open questions for such peptides (Mavrych et al., 2026). With no trustworthy figure, Pepti does not invent one.
If you have a half-life value from whoever directs your use, you can enter it into the half-life tool yourself, and the app will model decay from your number rather than from an assumption of ours. Whatever the half-life, the record can always capture the exact clock time of each administration — on a short-lived compound, precise timing is the most informative line in the log.
In the published human work, Semax is given intranasally, as a liquid (Lebedeva et al., 2018). Material prepared for injection is instead supplied as a powder that stays inert until a diluent is added; the two are different products, and a record that does not say which one it describes becomes ambiguous later. For a reconstituted vial, the concentration you create is the number every later draw depends on — so Pepti stores that concentration and the diluent volume as variables you enter.
Tracking Semax in Pepti is deliberately mechanical. If your vial is a powder, the reconstitution calculator turns the figures you already have — vial contents, diluent volume, the dose you were given — into a draw volume and a count of doses per vial, each held as a variable rather than a recommended amount. The injection-site rotation tracker keeps a 12-site sequence so the next administration lands somewhere other than the last. And because no trustworthy human half-life exists for this compound, the half-life calculator works only from a value you enter yourself.
Semax is not an approved medicine. There is no label from the FDA or the European Medicines Agency, so there is no authorised dose, no approved schedule, and no clinician-facing guidance outside the protocols of individual studies. Any figure published as a “typical dose” for an unapproved compound is not drawn from an approved source, because none exists — it comes from forum consensus, vendor copy, or someone’s reading of a study protocol run under monitoring conditions that do not apply elsewhere.
Pepti is a measurement and record-keeping tool. It converts a figure you already have into a draw volume and syringe units, tracks what is left in each vial, and remembers where the last injection went. It does not supply the figure, and it will not, for this compound or any other. Dose tables for unapproved peptides are folklore with the typography of evidence — authoritative-looking because they sit in a table, not because anything stands behind them. The figure belongs to you and whoever directs your use; the arithmetic is what we are for.
Because the effects people look for are largely subjective, the dated history is the part of a Semax log that earns its keep. A record worth keeping holds the following.
The method in full lives in the app: a peptide tracker keeps the dated log, the site sequence and your own entered half-life on one timeline, and the reconstitution calculator turns those figures into a draw volume and a count of doses per vial.
Semax is a synthetic peptide developed in Russia. It is an analogue of a short fragment of adrenocorticotropic hormone (ACTH): the ACTH(4-7) sequence extended with a Pro-Gly-Pro tail, which the literature labels ACTH(4-7)PGP and groups with the melanocortin derivatives (Filippenkov et al., 2020). It has been studied mainly in rats and in small groups of healthy human volunteers.
No. Semax is not approved by the US Food and Drug Administration or the European Medicines Agency for any use. Reviews of therapeutic peptides place it among non-approved agents that have promising preclinical and limited clinical evidence but lack long-term safety data and systematic validation (Mavrych et al., 2026).
No reliable human half-life has been published. The pharmacokinetic picture comes from preclinical and laboratory work rather than from human studies, and reviews list dosing and monitoring among the open questions for non-approved peptides like this one (Mavrych et al., 2026). If you have a half-life value from whoever directs your use, you can enter it yourself and Pepti will use that number.
Partly. The strongest mechanistic data come from rat studies of cerebral ischaemia and stress (Filippenkov et al., 2020; 2021). Human data exist but are limited to small studies in healthy volunteers, such as brain imaging after intranasal Semax in a few dozen participants (Lebedeva et al., 2018; Panikratova et al., 2020). These are small, mostly single-centre Russian studies, not large randomized trials.
No. Pepti supplies no dose figures for Semax or for anything else. It records the figure you already have from whoever directs your use, converts it into a draw volume and syringe units, tracks what is left in each vial, and keeps the injection-site sequence. The arithmetic is ours; the figure is not.
This page is a reference on published evidence and record-keeping. It does not recommend Semax or any other substance, and it provides no dose figure, no titration amount, and no schedule. Semax is not approved for any use by the FDA or the European Medicines Agency.
The Pepti peptide tracker for iPhone keeps the dated log, the site sequence, the vial count and your own entered half-life in one place.
Not medical advice. Pepti is a record-keeping and measurement tool, not a medical device.
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