Adamax vs Semax: What Is the Difference?

Semax is the original peptide: a seven-amino-acid ACTH(4-10) analogue (Met-Glu-His-Phe-Pro-Gly-Pro) with registered clinical use in Russia and more than 230 PubMed records, including human studies. Adamax is a supplier-made derivative of Semax that adds an acetyl group to the front of the chain and an adamantane group to the back, and it has no papers on PubMed. The difference is the end groups and the paper trail: Semax is the compound with published human data, and Adamax is a structural variant built on it. This page sets out how the two differ in structure, research and availability.

At a glance: Vistara Labs stocks Semax as a ready-mixed Semax Nasal Spray (10 mg in 5 mL, about 28 sprays, or 20 mg in 10 mL, about 57 sprays, 350 mcg per spray) and as a lyophilised Semax 10 mg vial, shipped from within Canada by Canada Post Xpresspost. Vistara Labs does not currently stock Adamax, but you can request it: contact us and we will source it for you.

Adamax vs Semax: what is the difference?

	Semax	Adamax
What it is	Synthetic ACTH(4-10) analogue	Synthetic derivative of Semax
Core sequence	Met-Glu-His-Phe-Pro-Gly-Pro	Same core
Front (N-terminal) end	Free amino group	Acetyl cap (supplier description)
Back (C-terminal) end	Free acid on proline	Adamantane group (supplier description)
PubChem	CID 9811102, C37H51N9O10S, 813.9 g/mol	No compound record
PubMed records	233 (October 2026)	None for the peptide
Human studies	Stroke recovery, brain imaging	None
Clinical status	Registered clinical use in Russia	Research chemical only
At Vistara Labs	Nasal spray and vial	Sourced on request

What is Semax?

Semax is a heptapeptide that joins the 4 to 7 fragment of adrenocorticotropic hormone (ACTH) to a Pro-Gly-Pro tail (Magrì, J Inorg Biochem, 2016). The tail removes the hormonal action of ACTH and slows breakdown, so the fragment keeps its activity in the brain. It was developed in Russia, where it has been in clinical use since the 1990s, most often as a nasal solution.

What is Adamax?

Adamax keeps the Semax sequence and changes both ends. Supplier listings describe an acetyl group on the N-terminal methionine and an adamantane group, a rigid ten-carbon cage, at the C-terminal end. The name comes from that adamantane group. Suppliers describe the purpose as greater fat-solubility and greater resistance to the enzymes that break Semax down.

No structure for Adamax is registered in PubChem. The one supplier deposit under the name, PubChem SID 513899171, lists a different sequence, Ac-Met-Glu-His-Phe-Pro-Gly-Pro-Ala-Gly-OH, with no adamantane. The name Adamax therefore refers to a family of capped Semax variants rather than one fixed molecule.

What does the research say about each?

Semax

• Stroke recovery, 2018. In 110 patients after ischaemic stroke, Semax raised plasma BDNF, which stayed high for the whole study. Semax and higher BDNF sped improvement and raised final Barthel Index scores (Gusev, Zh Nevrol Psikhiatr Im S S Korsakova, 2018).
• Brain networks, 2018. In healthy volunteers, intranasal Semax produced a greater volume of the medial frontal part of the default mode network on resting-state fMRI than placebo, measured 5 and 20 minutes after administration (Lebedeva, Bull Exp Biol Med, 2018).
• Brain connectivity, 2020. In 52 healthy participants, Semax and Selank each changed functional connectivity between the right amygdala and the right temporal cortex (Panikratova, Dokl Biol Sci, 2020).
• BDNF mechanism. In an animal model, intranasal Semax raised BDNF protein in the basal forebrain within 3 hours, and basal forebrain membranes held specific Semax binding sites (Dolotov, J Neurochem, 2006).

Adamax

A PubMed search for Adamax in October 2026 returned 39 records, all machine-learning papers using Adamax as the name of an optimisation algorithm. Searches for Adamax with Semax, and for Semax with adamantane, returned none. Adamax research to date is supplier description, and the published biology for this family is the Semax record above.

Why would anyone modify Semax?

Semax is broken down quickly from its ends. In animal serum, aminopeptidases, which trim a peptide from its front end, and angiotensin-converting enzyme accounted for most of the breakdown of Semax (Potaman, Peptides, 1993). Capping the ends is a standard way to slow that: in human plasma, N-terminal acetylation and C-terminal amidation markedly prolonged the stability of a short test peptide (Brinckerhoff, Int J Cancer, 1999). Adamax applies that idea with an acetyl cap at the front and adamantane at the back. A related variant, N-acetyl Semax amidate, uses an acetyl cap and a simple amide.

End groups can also change what a peptide does. In a cell study, acetylating the front of Semax changed how it bound copper, and the free amino end of unmodified Semax was what protected nerve-derived cells from copper toxicity (Magrì, 2016).

Which is better for research, Adamax or Semax?

• Semax is the choice when a protocol needs published reference points: human BDNF and imaging data, an identified binding site and a defined degradation profile to compare against.
• Adamax suits structure-activity work: asking how an adamantane cap changes the stability or behaviour of a Semax-type peptide, with Semax as the control.

For the cognitive pair, see Semax vs Selank; for the nasal and injected research routes, see Semax and Selank: Intranasal vs Subcutaneous Research Routes.

Where to get Semax in Canada

• Ready-mixed spray. The Semax Nasal Spray arrives pre-mixed in sterile saline in a sealed metered pump (0.175 mL per press): 10 mg in 5 mL, about 28 sprays, or 20 mg in 10 mL, about 57 sprays, at 350 mcg per spray.
• Combined spray. The Selank + Semax Nasal Spray holds 10 mg of each in 10 mL, about 57 sprays.
• Powder. The lyophilised Semax 10 mg vial, covered in Buy Semax in Canada.
• Domestic shipping. Every order ships from within Canada by Canada Post Xpresspost, with certificates on the lab reports page.

Frequently asked questions

What is the difference between Adamax and Semax?

Semax is the seven-amino-acid ACTH(4-10) analogue Met-Glu-His-Phe-Pro-Gly-Pro, with human studies and registered clinical use in Russia. Adamax is a supplier-made Semax derivative with an acetyl cap at the front and an adamantane group at the back, and it has no published papers.

Is Adamax stronger than Semax?

No study has compared them. Adamax has no papers on PubMed, so there is no published measurement of its potency against Semax.

Why is it called Adamax?

The name comes from adamantane, the rigid ten-carbon cage that suppliers describe attaching to the Semax chain.

Which has more research, Adamax or Semax?

Semax, with 233 PubMed records in October 2026, including a 110-patient stroke study and brain-imaging studies in healthy volunteers. Adamax has none.

Does Vistara Labs sell Adamax or Semax?

Vistara Labs does not currently stock Adamax, but you can request it: contact us and we will source it for you. Vistara Labs sells Semax as a ready-mixed nasal spray (10 mg or 20 mg, 350 mcg per spray) and as a 10 mg vial.

Product details from vistaralabs.ca, October 2026. Sources: Magrì A et al. Influence of the N-terminus acetylation of Semax, a synthetic analog of ACTH(4-10), on copper(II) and zinc(II) coordination and biological properties. J Inorg Biochem. 2016. PMID 27586814. Gusev EI et al. The efficacy of semax in the tretament of patients at different stages of ischemic stroke. Zh Nevrol Psikhiatr Im S S Korsakova. 2018. PMID 29798983. Lebedeva IS et al. Effects of Semax on the Default Mode Network of the Brain. Bull Exp Biol Med. 2018. PMID 30225715. Panikratova YR et al. Functional Connectomic Approach to Studying Selank and Semax Effects. Dokl Biol Sci. 2020. PMID 32342318. Dolotov OV et al. J Neurochem. 2006. PMID 16635254. Potaman VN et al. Degradation of ACTH/MSH(4-10) and its synthetic analog semax by rat serum enzymes: an inhibitor study. Peptides. 1993. PMID 8392718. Brinckerhoff LH et al. Terminal modifications inhibit proteolytic degradation of an immunogenic MART-1(27-35) peptide: implications for peptide vaccines. Int J Cancer. 1999. PMID 10495424. PubChem. Semax, CID 9811102; Adamax supplier deposit, SID 513899171.

More on this: Buy Semax Nasal Spray in Canada, Semax Benefits: What the Research Shows and How Many Sprays in a Peptide Nasal Spray?

More on nasal sprays and nootropic peptides: What Is Adamax?, N-Acetyl Semax Amidate, N-Acetyl Selank Amidate, Best Peptide Nasal Sprays in Canada, Semax vs Selank Nasal Spray.