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Selank
Out of stock · 10 mg
£30.00
£3.00/mg
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Neuropeptides
Semax
Semax is a synthetic heptapeptide. Supplied as a lyophilised powder in a sealed vial for laboratory research. Available in a 30 mg presentation.
Out of stock
30 mg vial£55.00
£1.83 per mg
≥99% purity (HPLC) · Independent third-party testing by PeptideVerify · COA Library
Free next-day tracked delivery on every order · Royal Mail Tracked 24
30 mg · £55.00 · £1.83/mg
At a glance
- Research area
- Neuropeptides · Explore the research area
- Presentations
- 30 mg
- Form
- Lyophilised powder in a sealed vial
- Purity
- ≥99% (HPLC)
- CAS number
- 80714-61-0
- Molecular formula
- C37H51N9O10S
- Molecular weight
- 813.92 g/mol
- Residues
- 7
- Monoisotopic mass
- 813.3480 Da
- Dispatch
- Order by 3pm Mon–Sat for same-day dispatch
About Semax
Semax is a synthetic heptapeptide, H-Met-Glu-His-Phe-Pro-Gly-Pro-OH. Its sequence is the fragment ACTH(4–7), Met-Glu-His-Phe, extended at the C-terminus by Pro-Gly-Pro. It is built only from standard amino acids, with a free N-terminal amine, a free C-terminal acid and no side-chain modification.
The catalogue lists CAS number 80714-61-0, the molecular formula C37H51N9O10S and a molecular weight of 813.92 g/mol. The single sulfur atom comes from the N-terminal methionine, which is also the residue most prone to oxidation: the sulfoxide is 16 Da heavier and is a typical related substance in HPLC. The phenylalanine and histidine give weak absorbance above 250 nm, and at this mass electrospray mass spectrometry shows mainly singly and doubly charged ions for comparison with the expected mass. Each presentation is supplied as a lyophilised powder in a sealed vial.
Identifiers
- PubChem CID 9811102
- CAS Common Chemistry: 80714-61-0 (opens in a new tab)
Further reading
Semax structure and analytical profile
In one-letter code the chain reads MEHFPGP: Met1, Glu2, His3, Phe4, Pro5, Gly6 and Pro7. The first four residues are the ACTH(4–7) fragment, residues 4 to 7 of the ACTH sequence, and Pro-Gly-Pro extends it at the C-terminal end. Every residue is a coded L-amino acid apart from glycine, which has no stereocentre.
The chain mixes a sulfur-containing residue (Met1), an acidic one (Glu2), an imidazole (His3) and an aromatic ring (Phe4) in its first half, then the proline-rich Pro-Gly-Pro tail. Prolines at positions 5 and 7 can take cis or trans peptide bonds, which may broaden the HPLC main peak slightly without changing the composition.
Histidine at position 3 gives the chain an imidazole side chain that is partly protonated near neutral pH, and phenylalanine at position 4 its only aromatic ring; with no tryptophan or tyrosine, absorbance at 280 nm is weak.
Both termini are free: Met1 keeps an amine and Pro7 a carboxylic acid. With Glu2 and the C-terminal carboxyl against the N-terminal amine and a partly protonated His3, the calculated net charge near pH 7 is about −0.8, so Semax is close to neutral and slightly acidic.
The methionine thioether is the one sulfur atom in the formula C37H51N9O10S and the most easily oxidised site in the chain. Its sulfoxide adds one oxygen, 16 Da, and elutes slightly earlier in reversed-phase HPLC, which makes it the first related substance an analysis checks.
Glu2 and the C-terminal carboxyl are the two acid groups and the N-terminal amine of Met1 the one fully basic group, which is why the chain sits close to neutral rather than carrying a clear positive or negative charge.
The monoisotopic mass is 813.3480 Da, so the [M+H]+ ion is expected at m/z 814.3552 and the [M+2H]2+ ion at m/z 407.6813. A +16 Da companion at m/z 830.35 marks the methionine sulfoxide. HPLC around 214 nm, where every peptide bond absorbs, gives purity as the main peak's share of total peak area.
Tandem mass spectrometry cleaves most readily on the N-terminal side of Pro5 and Pro7, and those fragments, together with the sulfoxide check, confirm sequence and oxidation state in one LC-MS run.
The material is a white to off-white lyophilised solid in a sealed vial. The sealed vial is stored at 2–8 °C short term, or at −20 °C and below for long-term storage, protected from light and away from repeated freeze-thaw cycles.
Semax and Selank: structure notes
| Property | Semax | Selank |
|---|---|---|
| Residues | 7 | 7 |
| Molecular formula | C37H51N9O10S | C33H57N11O9 |
| Average molecular weight | 813.92 g/mol | 751.87 g/mol |
| Monoisotopic mass | 813.3480 Da | 751.4341 Da |
| Net charge near pH 7 | −0.8 | +2.0 |
| Disulfide bridges | 0 | 0 |
Semax and Selank are both linear heptapeptides with free termini that end in Pro-Gly-Pro. Semax carries methionine, histidine and phenylalanine at 813.92 g/mol; Selank's tuftsin-based chain is basic and aromatic-free at 751.87 g/mol.
View SelankBuying Semax in the UK
Order Semax directly from British Peptide Labs, a UK-registered company, as a sealed vial in 30 mg presentation. Every size is listed below with its vial price and its price per mg, so the presentations compare at a glance.
| Presentation | Price | £/mg |
|---|---|---|
| Semax 30 mgOut of stock | £55.00 | £1.83 |
Priced at £1.83/mg, below the UK median of £3.50/mg across 9 suppliers in the October 2026 UK Research Peptide Price Index.
Choose a presentation in the buy box, add it to your basket and check out. Orders placed before 3pm Mon–Sat are packed the same working day and handed to Royal Mail Tracked 24, and your tracking number is emailed as soon as the parcel leaves us. Larger orders are welcome: add as many vials as your laboratory needs in a single basket.
For what other UK suppliers charge, see our UK price per mg data, updated every month.
Product information
- CAS number
- 80714-61-0
- Molecular formula
- C37H51N9O10S
- Molecular weight
- 813.92 g/mol
- Sequence
- Met-Glu-His-Phe-Pro-Gly-Pro
- Appearance
- White to off-white lyophilised powder
- Purity
- ≥99% (HPLC)
- Net content
- 30 mg per vial
- Storage (sealed vial)
- Store at 2–8 °C short term, or at −20 °C and below for long-term storage. Protect from light and avoid repeated freeze-thaw cycles
- Residues
- 7
- One-letter sequence
- MEHFPGP
- Monoisotopic mass
- 813.3480 Da
- Expected [M+H]+
- m/z 814.3552
- Net charge near pH 7
- −0.8
- PubChem CID
- 9811102
- Research use
- For laboratory research use only. Not for human or veterinary use.
Semax is a synthetic heptapeptide. Supplied as a lyophilised powder in a sealed vial for laboratory research. Available in a 30 mg presentation. Store the sealed vial at 2–8 °C for short-term storage, or at −20 °C and below for long term. Protect from light and avoid repeated freeze-thaw cycles. For research use only. Not for human or veterinary use. Sold strictly for in-vitro laboratory research; not for diagnosis or treatment.
- Packing
- Each sealed vial travels in protective packing.
- Dispatch
- Orders placed before 3pm Mon–Sat leave the same day.
- Delivery
- Next-day tracked delivery with Royal Mail Tracked 24.
- Tracking
- Your tracking number is emailed as soon as the order is dispatched.
- Delivery cost
- Delivery is free on every order.
Questions about Semax
Semax is a synthetic heptapeptide. It is supplied in a sealed vial as a white to off-white lyophilised powder, in a 30 mg presentation.
Read the Learn article813.3480 Da, against an average molecular weight of 813.92 g/mol. The [M+H]+ ion is expected at m/z 814.3552 and the [M+2H]2+ ion at m/z 407.6813. A +16 Da companion at m/z 830.35 marks the methionine sulfoxide.
MEHFPGP, read from the N-terminal methionine to the C-terminal proline. With free termini the full form is H-Met-Glu-His-Phe-Pro-Gly-Pro-OH.
80714-61-0, the number CAS Common Chemistry records for this heptapeptide, with the formula C37H51N9O10S. PubChem lists the compound as CID 9811102.
About −0.8. Glu2 and the C-terminal carboxyl carry negative charges, the N-terminal amine a positive one, and His3 is only partly protonated, so the peptide is close to neutral. With no aromatic residue other than phenylalanine, the chain absorbs only weakly at 280 nm.
The N-terminal methionine. Its sulfoxide is 16 Da heavier, appears at m/z 830.35 as the [M+H]+ ion, and is the typical related substance in HPLC.
It names residues 4 to 7 of the ACTH sequence, Met-Glu-His-Phe, which form the first four residues of Semax. The C-terminal Pro-Gly-Pro completes the seven-residue chain.
Seven: methionine, glutamic acid, histidine, phenylalanine, proline, glycine and proline, all coded amino acids with no side-chain modification. Prolines at positions 5 and 7 and glycine at position 6 form the C-terminal Pro-Gly-Pro tail, and the single sulfur atom in the formula belongs to Met1.
Order Semax directly from British Peptide Labs, a UK-registered company. It is supplied in a sealed 30 mg vial at £55.00 (£1.83 per mg). Every vial is ≥99% purity (HPLC), with independent third-party testing by PeptideVerify. Orders placed before 3pm Mon–Sat leave the same day by Royal Mail Tracked 24 for next-day tracked delivery.
Semax comes in one sealed vial: 30 mg at £55.00 (£1.83 per mg). Delivery is free on every order.
Semax is catalogued in the Neuropeptides research area, where compounds are grouped by molecular class. The research area page lists each of them with its identifiers.
Neuropeptides research areaSemax has independent third-party testing by PeptideVerify: reversed-phase HPLC measures purity, at ≥99% (HPLC), and LC-MS confirms identity against the expected mass.
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