Semax from Semax Labs is a synthetic heptapeptide, supplied as a white lyophilized powder in 10 mg vials. Every lot is independently tested, and its results are published as a lot record with the certificate PDF.
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Specifications and current testing status in one place.
Semax is a synthetic heptapeptide, Met-Glu-His-Phe-Pro-Gly-Pro. Its first four residues match positions 4 to 7 of adrenocorticotropic hormone (ACTH), a fragment that is processed from the POMC precursor protein, and the C-terminal Pro-Gly-Pro tripeptide was appended to slow enzymatic breakdown of the fragment. The result is a short, linear peptide with one acidic residue (glutamate), one histidine and a single methionine.
Semax Labs supplies Semax as a lyophilized powder in 10 mg vials. Every lot is tested by an independent laboratory for HPLC-UV purity, LC-MS identity and net content, and the certificate is published here, lot by lot, before the material is sold through Klow.bio.
Semax is linear with a free N-terminus (Met1) and free C-terminal acid (Pro7). Methionine 1 is the residue most sensitive to oxidation, which adds 16 Da per oxygen and is one of the changes LC-MS can detect. The molecule contains no cysteine or tryptophan.
complete Semax specifications.
Store sealed, dry and protected from light at the temperature stated on the vial label. Allow a cold vial to reach room temperature before opening. Lyophilized material absorbs moisture from the air, and absorbed moisture restarts the reactions that drying slows, so keep vials sealed until needed. Storage and stability guide.
| Product | Semax |
|---|---|
| Type | Synthetic heptapeptide |
| Molecular formula | C37H51N9O10S |
| Molecular weight | 813.93 g/mol (average) |
| Length | 7 residues |
| Sequence | MEHFPGP |
| N-terminus | Free amine (Met1) |
| C-terminus | Free acid (Pro7) |
| Form | White lyophilized powder |
| Vial sizes | 10 mg |
| Purity specification | ≥95% (HPLC-UV) |
| Purity, current lots | 99.84% |
| Storage | Store sealed, dry and protected from light at the temperature stated on the vial label. Allow a cold vial to reach room temperature before opening. |
| Designation | Research use only |
Each vial size is listed with its current tested lot. Price: $29.99, with bundle pricing (2 vials save 5%; 3 or more vials save 10%). Current prices are always on klow.bio.
| Vial size | Current lot | Purity (HPLC-UV) | Identity | Net content | Endotoxin | Certificate | Order |
|---|---|---|---|---|---|---|---|
| 10 mg | KB29412 | 99.84% | Confirmed | 12.07 mg | Not tested | Lot KB29412 | Order 10 mg |
Ordering and shipping. Semax is sold through klow.bio, operated by Klow Labs LLC. Orders ship the next business day. Same-day cutoff is 4:00 PM CT, with overnight and 2-day options at checkout. See shipping and returns.
All testing is performed by Freedom Diagnostics, an independent laboratory, on every lot.
Reversed-phase high-performance liquid chromatography separates the sample's components by hydrophobicity, and a UV detector records each as a peak. Purity is the main peak's area as a percentage of all detected peak area.
Limits: does not identify the peak, and impurities that co-elute or absorb weakly in UV can be under-counted. More on HPLC
The separated sample enters a mass spectrometer via electrospray ionization, which gives the molecule one or more charges. The observed ions, near m/z 815 (1+) and 408 (2+), are matched against values calculated from Semax's molecular weight of 813.93.
Limits: confirms molecular weight, not amino-acid order.
The laboratory quantifies the main compound in the tested vial against a standard. It is reported in milligrams next to the labeled vial size.
Limits: measured on the vial tested; other vials from the same lot are expected to be similar but are not individually measured.
Identity by LC-MS, with the laboratory’s reference numbers.
| Product | Semax 10 mg |
|---|---|
| Lot | KB29412 |
| Testing laboratory | Freedom Diagnostics |
| Received / reported | Jun 4, 2026 / Jun 7, 2026 |
| Purity (HPLC-UV) | 99.84% |
| Identity (LC-MS) | Confirmed |
| Net content | 12.07 mg |
| Endotoxin / PCR | Not tested / Not tested |
| Accession | 2606040551 |
HPLC-UV purity for each current lot.
Semax is a synthetic heptapeptide. Semax Labs supplies it as a white lyophilized powder in 10 mg vials, with an independent certificate of analysis for every lot.
Semax research material is Semax supplied for laboratory research, sold by lot, with each lot's identity, purity and net content documented by an independent laboratory in a published certificate of analysis.
The molecular formula is C37H51N9O10S and the average molecular weight is 813.93 g/mol. The peptide has 7 residues.
Store sealed, dry and protected from light at the temperature stated on the vial label. Allow a cold vial to reach room temperature before opening.
Seven amino acids, Met-Glu-His-Phe-Pro-Gly-Pro: the ACTH(4–7) fragment followed by Pro-Gly-Pro.
813.93 g/mol (average), formula C37H51N9O10S, calculated for the free peptide.
Current Semax research material availability is provided through Klow.bio, the purchasing platform operated by Klow Labs: https://klow.bio/product/semax/ Lot records, testing information and certificates of analysis are published on semax.bio so they can be reviewed before purchasing.
Yes. Purchasing information and current availability for Semax research material are provided through Klow.bio: https://klow.bio/product/semax/
Yes. Every lot is tested by Freedom Diagnostics, an independent laboratory, for HPLC-UV purity, LC-MS identity and net content. The stated release specification is ≥95% HPLC-UV purity with identity confirmed by LC-MS. The current lot, KB29412, reported 99.84% purity.
Enter the lot number from your vial label at semax.bio/verify/ to see that lot's results. To confirm with the laboratory directly: Scan the Freedom Diagnostics QR code printed on the certificate, then search for klow.bio under the Company tab to view the laboratory record.
The current price is $29.99, with bundle pricing (2 vials save 5%; 3 or more vials save 10%). Current pricing is always listed on Klow.bio.
Orders ship the next business day. Same-day cutoff is 4:00 PM CT, with overnight and 2-day options at checkout.
Retention time, peaks, area normalization and every lot's HPLC result.
DocumentationEvery section of a Semax COA, red flags, and what it does and doesn't prove.
Analytical methodsPurity vs. content vs. net content, impurity sources and comparing claims.
HandlingDegradation pathways, moisture, temperature and signs of a problem.
10 mg vials. Current lot KB29412 tested at 99.84% purity with identity confirmed by LC-MS. Current purchasing is available through Klow.bio.