Semax

Semax is a synthetic heptapeptide consisting of the ACTH (4-7) fragment Met-Glu-His-Phe extended with the C-terminal tripeptide Pro-Gly-Pro, an addition intended to slow enzymatic degradation. It is supplied as a lyophilised powder. Identity is confirmed by mass spectrometry against the calculated mass and purity by reversed-phase HPLC with a stated gradient; the methionine residue makes oxidation a specific related-substance concern that a competent purity method should resolve. Values on this record are transcribed from supplier documentation.

Semax was developed in the Soviet Union and later Russia from the 1980s onward, as part of a research programme on non-hormonal ACTH fragments intended to retain central nervous system activity without corticotropic effects. It is registered as a medicine in Russia for certain indications. That registration is important context and equally important not to overstate: it does not correspond to review by the FDA or EMA, and the trial evidence supporting it is largely published in Russian-language journals that are unevenly indexed and infrequently subject to independent replication.

Published work examines effects on brain-derived neurotrophic factor and nerve growth factor expression in rodent brain tissue, modulation of dopaminergic and serotonergic turnover, effects on gene expression profiles in rodent cortex and hippocampus, and behavioural endpoints in learning, attention and stress models. Work in ischaemia models examined neurological deficit scores and infarct measures. Effects on the melanocortin receptor family and on non-corticotropic ACTH fragment activity are also discussed in the literature.

The absence of corticotropic activity relative to intact ACTH is well established, which was the original design goal. Elevation of neurotrophic factor expression in rodent brain tissue has been reported across multiple studies. Enzymatic stabilisation conferred by the Pro-Gly-Pro extension relative to the bare ACTH fragment is supported by degradation data. Analytical characterisation is straightforward.

Within the rodent literature, neurotrophic factor expression findings have been reported by more than one group and using more than one measurement method, which is the strongest form of consistency available in this record. Degradation studies supporting the stabilising role of the Pro-Gly-Pro extension are straightforward biochemistry and are not in dispute.

There are no completed randomised controlled trials meeting Western regulatory standards for any indication, and no FDA or EMA approval exists. The clinical literature supporting the Russian registration consists largely of small studies, often with limited blinding detail, incomplete reporting of randomisation and allocation concealment, and publication in journals not widely indexed; several are unavailable in English. Independent replication outside the originating research network is scarce. Rodent behavioural studies use small groups and endpoints that translate poorly. Pharmacokinetic characterisation in humans, particularly central nervous system exposure after peripheral administration, is limited. Claims about cognitive enhancement in healthy people rest on no adequately controlled evidence at all.

Language and indexing are practical evidentiary barriers here, not excuses. When the majority of supporting studies cannot be retrieved, read in full, or assessed for methodological quality by an independent reader, the correct posture is reduced confidence rather than deference to volume. Counting papers is not appraising them, and a citation the reader cannot examine is not evidence the reader can rely on.

Store the lyophilised solid as stated on this record, protected from light and moisture, with the sealed vial equilibrated to ambient temperature before opening. Methionine-containing peptides are susceptible to oxidation, so exposure to air and to oxidising buffer components is a specific handling concern. This section describes laboratory handling of the material as supplied and contains no preparation or administration procedure.

Indexed citations with verified PMIDs appear below; where a study exists only in a non-indexed source it is not cited here. See testing methodology and sourcing standards.