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Neuropeptides & other compounds · 7 amino acids · CAS 80714-61-0

Semax

A synthetic heptapeptide made from residues 4 to 7 of ACTH with a Pro-Gly-Pro extension, supplied as a lyophilised research powder in 30 mg vials with an independent HPLC and LC-MS certificate for every batch.

Vial size
£41.00BK-SEMAX-30 · In stock, dispatched today before 3pm

For in-vitro research use only. Not for human or veterinary use. 18+.

Certificate of analysisLot BK-SEMAX-30
Semax 30 mg
Purity, RP-HPLC, 220 nm
99.15 %
Laboratory
Janoshik
Signed report (PDF)Batch page

About Semax

Written for laboratory researchers from the published literature. Not medical advice; nothing on this page describes use in humans or animals.

What Semax is

Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues are positions 4 to 7 of adrenocorticotropic hormone (ACTH), a fragment chosen because it has no endocrine action of its own. The Pro-Gly-Pro tripeptide was added to the C-terminus to protect the fragment from the peptidases that would otherwise clear it within minutes.

Semax was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences, which also produced Selank. The molecular weight is approximately 814 g/mol and the CAS number is 80714-61-0. Unlike the full hormone, the ACTH(4–7) fragment has no activity at the MC2 receptor and does not stimulate the adrenal cortex. Semax belongs to the neuropeptides and other class.

The published literature on the compound, with references, is collected in the monograph.

What you receive

Each vial contains Semax as a white lyophilised powder, sealed with a flip-off cap over a crimped stopper, in the net quantity stated on the label: 30 mg. There is no carrier, mannitol or other excipient unless the batch certificate says otherwise. The batch number is printed on the label and matches the certificate in our register.

Reading the certificate for a Semax batch

Purity by reversed-phase HPLC is reported as the area of the main peak against all peaks and should be above 99%. Identity by LC-MS is reported as the observed mass against the expected mass of about 814 Da, usually seen as the singly charged ion near 815 and the doubly charged ion near 408. Net content gives the milligrams of peptide actually present, as distinct from the nominal fill.

The specific thing to check on a Semax certificate is methionine oxidation. The N-terminal methionine converts to its sulfoxide on exposure to air, and the product is 16 Da heavier and elutes slightly earlier on HPLC. A well-made and well-stored batch shows this at a fraction of a percent; a certificate showing several percent of the sulfoxide indicates poor handling somewhere in the chain. Deletion sequences missing one proline, 97 Da lighter, are the other impurity to expect. Our guide to reading a certificate of analysis walks through annotated examples, and HPLC and LC-MS explained covers the methods.

Storage and handling

Sealed vials should be kept refrigerated at 2 to 8 °C and protected from light; −20 °C is preferable beyond a few months, and the methionine makes this more important for Semax than for peptides without an oxidisable residue. Allow the vial to reach room temperature before opening to avoid condensation, and reseal promptly, since both moisture and oxygen accelerate sulfoxide formation. Semax dissolves readily in water or buffer. Solutions are best prepared fresh, or aliquoted and frozen under nitrogen or argon where possible; the storage and stability guide covers solvents, concentrations and freeze-thaw behaviour.

Specification

Reference values pending verification against the batch certificate.

CAS number
80714-61-0
Molecular formula
C37H51N9O10S
Molecular weight
813.9 g/mol
Sequence
Met-Glu-His-Phe-Pro-Gly-Pro
Appearance
White to off-white lyophilised powder
Purity
≥99% by RP-HPLC, per batch certificate
Net content
30 mg
Storage, sealed
2–8 °C short term; −20 °C or below long term; protect from light; avoid freeze–thaw cycles
Storage, reconstituted
2–8 °C; use within the period stated in the compound monograph
Research use
In-vitro laboratory research only

Questions about Semax

How does Semax differ from Selank?

They were designed by the same group on the same principle, a short bioactive fragment stabilised by a Pro-Gly-Pro tail, but from different parents. Semax draws its first four residues from ACTH, the pituitary hormone, while Selank draws its from tuftsin, an immunoglobulin fragment. Semax contains a methionine and Selank does not, which matters for handling and for reading the certificate.

What does the certificate for a Semax batch show?

It reports purity by reversed-phase HPLC as area-percent of the main peak, identity by LC-MS against an expected mass of about 814 Da, and the net content per vial. The result to look for specifically is the absence of a peak 16 Da heavier than the main ion, which would indicate oxidation of the methionine residue. The signed PDF is linked from the batch page.

Why is Semax offered in a 30 mg vial rather than 10 mg?

The in-vitro and tissue-preparation literature on Semax tends to use higher concentrations and larger volumes than the receptor-binding work typical of other peptides, so a laboratory consumes more of it per experiment. At about 814 g/mol, 30 mg is roughly 37 micromoles. One larger vial from a single tested batch is more economical than three small ones.

Does Semax have the hormonal activity of ACTH?

No. ACTH stimulates the adrenal cortex through the MC2 receptor, and that activity requires a longer stretch of the hormone than the four residues used in Semax. The published characterisation reports that Semax lacks corticotropic activity and does not act as a melanocortin agonist, which is why the fragment was chosen as a starting point.

What is in the vial?

Semax as a white to off-white lyophilised powder, sealed under nitrogen, in the net quantity stated on the label. No carrier, no excipient unless the certificate says otherwise.

Which batch will I receive?

The batch shown in the certificate panel for the size you choose. Its number is printed on the vial and on your dispatch note, and its full report is on the batch page.

How is purity measured?

By reversed-phase HPLC at an independent laboratory, reported as the area of the main peak against all peaks. Identity is confirmed by LC-MS against the expected mass.

How should the sealed vial be stored?

2–8 °C short term; −20 °C or below long term; protect from light; avoid freeze–thaw cycles

When is my order dispatched?

Same day for orders placed before 3pm, Monday to Saturday, by Royal Mail Tracked 24. Delivery is free.

Who may buy?

Researchers and institutions aged 18 or over, for in-vitro laboratory use under our terms. Nothing we sell is for human or veterinary use.

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