Research-use-only context. This article is an educational research overview. It provides no administration or usage guidance for any human or animal use and makes no therapeutic or efficacy claims. American Peptides products are sold strictly for in vitro laboratory research only.
Semax is a synthetic peptide derived from a fragment of the adrenocorticotropic hormone sequence, ACTH(4–10), extended with a Pro-Gly-Pro tail for stability. In research models it is studied for its interaction with BDNF (brain-derived neurotrophic factor) and related neurotrophic signaling pathways, and — like Selank — it is commonly examined in an intranasal research format.
The structure of Semax
Semax has the amino-acid sequence Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the 4–7 region of ACTH; the Pro-Gly-Pro tail was added to slow enzymatic degradation, giving the peptide greater stability than the native ACTH fragment. Critically, Semax retains the fragment's studied signaling behavior without the steroidogenic (hormone-releasing) activity of full-length ACTH — which is much of why it became a research peptide of interest.
Why Semax is studied intranasally
As a short, water-soluble peptide, Semax is a natural candidate for the intranasal research route. The nasal mucosa's thin, vascular lining absorbs small peptides rapidly and without reconstitution or needle-based handling, which is why Semax is so frequently studied as a nasal spray. The broader route comparison is covered in Peptide Delivery Methods Explained.
Pathways studied in the literature
In animal-model and in vitro research, Semax is examined primarily for its influence on BDNF and nerve growth factor (NGF) expression and downstream neurotrophic signaling, as well as for effects on markers associated with attention and cognitive-research endpoints. These are molecular and behavioral endpoints measured in non-human research models — not human-use outcomes.
Semax and Selank: sister research peptides
Semax is often paired with Selank. The two are structurally distinct — Semax from ACTH, Selank from Tuftsin — but both are small synthetic peptides studied in neuroscience and commonly delivered intranasally in research, which is why they are frequently offered together.
Format and quality
American Peptides offers Semax as a ready-to-use research nasal spray, third-party tested with a Certificate of Analysis:
- Semax Nasal Spray — pre-mixed, needle-free research format.
- Selank + Semax Nasal Spray — combined research format.
Verify identity and purity on the third-party COA before any research use.
Frequently Asked Questions
What is Semax?
Semax is a synthetic peptide (Met-Glu-His-Phe-Pro-Gly-Pro) derived from the ACTH(4–10) fragment with an added Pro-Gly-Pro stabilizing tail. It is studied in neuroscience research for BDNF and neurotrophic-pathway signaling in research models and is sold strictly for research use only.
What is Semax derived from?
Semax is derived from a fragment of adrenocorticotropic hormone, ACTH(4–10). It retains the fragment's studied neural-signaling behavior without the hormone-releasing (steroidogenic) activity of full-length ACTH.
What is Semax nasal spray?
Semax nasal spray is a pre-mixed research solution delivered as a metered mist to the nasal mucosa. The intranasal route is studied because it absorbs small peptides rapidly and needle-free, without reconstitution. It is a research-use-only product.
How is Semax different from Selank?
Both are short synthetic neuroscience-research peptides, but they are unrelated in structure: Semax is an ACTH(4–10)-fragment analog studied around BDNF and neurotrophic pathways, while Selank is a Tuftsin analog studied around GABAergic pathways.
Is Semax research use only?
Yes. American Peptides Semax — including the nasal-spray format — is sold strictly for laboratory research use only and is not intended for human or veterinary use.
Related reading: What Is Selank? · Intranasal Peptide Delivery · Peptide Delivery Methods Explained. Verify identity and purity for any format on the COA library.
Reviewed by the American Peptides Education Team. Educational content only — not medical advice.
This article is for laboratory research reference only. American Peptides research peptides are sold strictly for in vitro research and are not for human consumption.
Compliance Notice: American Peptides research peptides are sold strictly for laboratory and academic research purposes only. They are not intended for human or veterinary consumption, diagnosis, treatment, or prevention of any disease. All content on this page is educational in nature and does not constitute medical advice or product claims. Researchers are responsible for handling these compounds in accordance with their institution's safety protocols and applicable laws.
