Research peptide
Semax research peptide, 11 mg, lyophilized, COA published
Synagenics Semax is a synthetic heptapeptide supplied as a lyophilized research material for qualified laboratories. The certificate of analysis for lot SEMAX-11-0726 reports over 99% HPLC purity with identity confirmed by LC-MS, and the full report is public.
Semax product data
Identifying details researchers confirm before ordering.
| Compound | Semax (Met-Glu-His-Phe-Pro-Gly-Pro) |
|---|---|
| Peptide sequence | Met-Glu-His-Phe-Pro-Gly-Pro, seven amino acids |
| Molecular formula | C37H51N9O10S |
| Molecular weight | about 813.9 g/mol |
| CAS number | 80714-61-0 |
| Supplied amount | 11 mg per vial |
| Form | Lyophilized powder |
| Purity (HPLC) | over 99% on lot SEMAX-11-0726 |
| Identity (LC-MS) | Confirmed on lot SEMAX-11-0726 |
| COA reported | June 28, 2026 |
| Grade | Research use only (RUO) |
About Synagenics Semax
Semax is a seven-residue synthetic peptide. Its first four residues, Met-Glu-His-Phe, match positions 4 to 7 of adrenocorticotropic hormone (ACTH), and a Pro-Gly-Pro tail is added at the C-terminus. The proline-rich tail resists cleavage by many peptidases, which makes the analog more stable in biological media than the bare ACTH fragment.
In the laboratory, Semax serves as a defined, stable peptide for neuronal cell culture work and for peptidase stability assays. For the chemistry, model systems and experimental-design guidance, read our Semax research overview.
What comes with every order
Documentation is part of the product.
Lot-tracked vial
The lot number is printed on the vial, so it matches the certificate in the public library.
Published certificate
HPLC chromatogram and purity, LC-MS identity and the report date, open to read before you order.
Research-use labeling
Clear RUO labeling on every vial, with no claims about people or animals.
Check the data before you order
You can verify our Semax without an account.
Open the COA library
Go to synagenics.com/coas/ and find the Semax 11 mg report.
Read the chromatogram
Look for one dominant peak on a flat baseline. The reported HPLC purity is over 99%.
Check the identity
LC-MS should confirm the intact heptapeptide at about 813.9 g/mol.
Match the lot
Confirm the lot number on your vial matches SEMAX-11-0726 or the lot named on the report you are shown.
Laboratory research applications
Semax appears in the literature across several in vitro and biochemical settings. These describe model systems, not any use beyond the bench.
- Neuronal cell culture. Neuronal-like cell lines and primary cultures, with matched controls.
- Neurotrophin expression. Transcript and protein readouts by RT-qPCR, ELISA or western blotting.
- Peptidase stability assays. LC-MS or HPLC tracking of the intact peptide in serum or buffer with defined peptidases.
- Receptor binding assays. Competition assays with appropriate positive and negative controls.
Design guidance and controls are in the Semax research overview.
What methionine means for analysis
Semax contains a methionine residue, which can oxidize to methionine sulfoxide during synthesis, handling or analysis. The oxidized form is 16 Da heavier than the parent peptide, so a mass spectrum that resolves the parent ion from a +16 Da species shows whether oxidation is present.
That is why identity data matters as much as purity for this peptide. When you review a certificate, check that the observed mass matches about 813.9 g/mol and that no large unexplained signal sits 16 Da above it. Chromatographic purity alone cannot tell you that.
Plan your purchase for the whole study
- Estimate total need. Calculate how much peptide the full study will consume, including repeats, and allow a margin.
- Prefer one lot. Where practical, source the study from a single lot and record the lot number with every dataset.
- Account for net peptide content. Powder mass includes counter-ion and bound water, so concentrations calculated from weight alone can be too high.
- Use matched controls. A scrambled heptapeptide and the Met-Glu-His-Phe fragment help separate sequence effects from the effect of the tail.
- State the medium. Serum contains peptidases, so record the serum percentage and consider a serum-free condition.
How to compare Semax suppliers
Semax product pages look alike. The documentation is what differs.
| Lot-specific certificate | A report that names the exact lot you will receive, not a generic sheet. |
|---|---|
| Full chromatogram | The trace itself, not only a percentage. |
| Identity by mass spectrometry | Observed mass near 813.9 g/mol, with no dominant +16 Da species. |
| Independent testing | Third-party data rather than a self-issued report. |
| Stated identifiers | Sequence, molecular weight and CAS number that match the compound you intend to use. |
| Research-use language | A supplier that implies use in people is not operating as a research supplier. |
Responsible purchasing for research
Synagenics supplies Semax to qualified laboratories and researchers for laboratory use only. Buyers are responsible for using the material lawfully and in line with their institution’s procurement, safety and ethics policies. The product is not a drug, supplement or cosmetic, and nothing on this page is a claim about use in people or animals.
Questions? Email support@synagenics.com. To learn how we test every lot, read Setting the Standard at Synagenics and From Our Lab.
Key takeaways for Semax buyers
- Check identity as well as purity: the mass spectrum should show the intact peptide and no dominant oxidized species.
- Match the lot on your vial to the certificate before you use it.
- Calculate concentrations from net peptide content where it is available.
- Source a long study from one lot where practical.
- Use Semax strictly for laboratory research, within your institution’s policies.
Semax in context: what the peptide is used to study
Semax belongs to a long tradition of using short peptide fragments to probe larger signaling molecules. A fragment of ACTH separates the effect of the receptor-binding core from the effect of the whole hormone, and adding a stabilizing tail then asks a second question: how much of a peptide’s behavior in a culture dish is driven by its sequence, and how much by how long it survives in the medium?
That second question is why stability work sits beside cell-based assays in the Semax literature. A peptide degraded within minutes of reaching the culture will give a very different result from one that persists for hours, even when both bind the same target. Good experiments therefore measure the intact peptide at the start and end of an incubation and report the half-life they observed under their own conditions.
Designing a clean in vitro experiment with Semax
- Pick the right controls. Use a vehicle control, a scrambled heptapeptide and the Met-Glu-His-Phe fragment alone.
- Measure the intact peptide. Use LC-MS or HPLC to confirm how much Semax remains at the end of the incubation.
- Standardize the cells. Hold passage number, plating density and differentiation protocol constant across arms.
- Define the endpoint in advance. Decide the readout, the time points and the statistical test before you start.
- Replicate independently. Independent biological replicates started on separate days matter more than many wells in one run.
- Record the lot. Keep the lot number with every dataset so the work can be repeated.
For the full guide, including a glossary of neuropeptide and stability terms, see the Semax research overview.
Understanding the numbers on the Semax certificate
The certificate for lot SEMAX-11-0726 reports a purity of over 99% by HPLC. That figure means the main peak accounts for over 99 percent of the integrated area in the chromatogram. It does not say how much of the powder is peptide, which is why net peptide content is a separate question when you calculate a stock concentration.
The identity result comes from LC-MS, which separates the sample by chromatography and then measures the mass of what elutes. For Semax the expected mass is about 813.9 g/mol, and the report confirms that the intact peptide is present. Open the report in the COA library and compare the chromatogram and the mass spectrum yourself.
Common questions researchers ask before using Semax
- How long does the peptide persist in my medium? Measure it. Serum peptidases vary by lot, so confirm the intact peptide by LC-MS at the end of the incubation.
- Do I need a serum-free control? It is a useful comparison, because it separates peptide stability from peptide activity.
- Which mass should I expect? About 813.9 g/mol for the intact heptapeptide, with an oxidized species 16 Da higher if methionine has oxidized.
- What should I record? The lot number, the net peptide content used for concentration, the medium, the serum percentage and the incubation time.
Our Cellular Research Hub covers general cell culture design in more depth.
Buying Semax for research: FAQ
What is Synagenics Semax?
It is the synthetic heptapeptide Met-Glu-His-Phe-Pro-Gly-Pro, supplied as an 11 mg lyophilized research material.
Is Semax sold for human or animal use?
No. It is sold strictly for qualified laboratory research. It is not a drug, supplement or cosmetic, and nothing on this page is a claim about use in people or animals.
What purity does the Semax certificate report?
The certificate for lot SEMAX-11-0726 reports over 99% purity by HPLC, with identity confirmed by LC-MS, reported June 28, 2026.
Where can I read the certificate?
In the public Certificate of Analysis library at synagenics.com/coas/, with no account required.
Why does methionine oxidation matter?
Methionine can oxidize to the sulfoxide, adding 16 Da to the mass. A mass spectrum that resolves this species shows whether oxidation is present in a lot.
Who do I contact with questions?
Email support@synagenics.com with the compound name and your lot number if you have one.
Related research
Continue exploring the Synagenics research library.
Order research-grade Semax
Independently tested, with the certificate published for you to read first.
For qualified laboratory research use only. Not for human or animal use. These statements have not been evaluated by the US Food and Drug Administration.