Semax: ACTH(4-10) Analog Research Overview

Semax is a synthetic heptapeptide built on the ACTH(4-10) fragment of adrenocorticotropic hormone with an added C-terminal Pro-Gly-Pro extension. The extension is described in the literature as improving resistance to enzymatic degradation relative to the unmodified fragment. Despite the ACTH lineage, published work characterizes Semax as lacking the corticotropic hormonal activity of full-length ACTH while retaining neuropeptide-like signaling activity in animal models.

It is studied alongside a family of structurally related short proline-containing peptides — the glyprolines, including Pro-Gly-Pro itself and the tuftsin analog Selank — largely by the same Russian research groups that originally developed it.

Molecular formula and molecular weight values circulate widely online for Semax but were not confirmed against a primary analytical source, so North Summit Labs does not state them. The lot-specific certificate issued by the independent testing laboratory is the authoritative record of identity and purity for the material you receive.

The Semax literature is dominated by preclinical rodent work. Several studies use rat models of focal cerebral ischemia — middle cerebral artery occlusion or photothrombotic stroke — combined with genome-wide microarray or RNA-sequencing transcriptomic analysis, to describe how Semax and related ACTH(4-10) and glyproline peptides alter expression of genes tied to inflammation, immune signaling, neurotrophins and their receptors, and vascular response in the days after ischemic injury.

Dmitrieva and colleagues reported that Semax and Pro-Gly-Pro were associated with changes in transcription of neurotrophin and neurotrophin-receptor genes after experimental cerebral ischemia. Medvedeva and colleagues carried out a genome-wide transcriptional analysis reporting peptide-associated shifts in immune- and vascular-system gene clusters in rat brain focal ischemia. More recent work from the same lineage of groups has examined immune gene expression patterns in the early post-stroke period and compensation of ischemia-disrupted expression profiles.

Outside the ischemia models, a 2024 study used a chronic unpredictable stress paradigm in male rats to compare behavioral readouts for Semax and Melanotan II, both described as ACTH(4-10) synthetic analogs.

These are animal and tissue-level studies reporting gene-expression associations and rodent behavioral observations. They are not human clinical trials, and no phase III randomized controlled trials for Semax were identified. Findings of altered transcription in rat brain tissue do not establish a therapeutic effect in humans, and this monograph makes no such claim.

A further limitation worth noting for anyone reviewing the literature: most primary studies originate from a small, overlapping set of research groups, and several key clinical reports exist only in Russian-language journals without independent replication in the English-language literature.

Semax is registered as a prescription nasal-drop product in Russia and certain CIS states. It is not approved by the FDA and has no approved medical use in the United States, the European Union, or most other jurisdictions. Material available outside those registration contexts — including material sold by North Summit Labs — is a laboratory research chemical, not a medicine.

Semax is supplied as a lyophilized powder in a sealed vial. General laboratory practice for lyophilized peptides applies: keep vials sealed and protected from moisture, heat, and light; allow refrigerated or frozen material to reach room temperature before opening to limit condensation; reconstitute with a solvent appropriate to the intended assay; and aliquot to avoid repeated freeze-thaw cycles.

Short peptides of this class are studied in part because of degradation questions, so investigators frequently document reconstitution date, solvent, concentration, and storage conditions alongside their results. See our laboratory storage guide for a fuller treatment.

Each Semax lot listed in our catalog is submitted to an independent analytical laboratory, and the resulting certificate reports identity and chromatographic purity for that specific lot. Published certificates are in the COA library, and the certificate matching the lot number on your vial is available on request.

This monograph summarizes published scientific literature for educational and reference purposes only. It is not medical, veterinary, clinical, or dosing guidance, and nothing here should be read as a claim that this compound is safe, effective, or approved for use in humans or animals.

Material supplied by North Summit Labs is intended strictly for in-vitro laboratory research by qualified professionals. It is not a drug, supplement, food, cosmetic, or medical device, and it is not for human or animal consumption. Investigators are responsible for complying with their own institutional oversight, biosafety, and legal requirements.