Semax is a synthetic heptapeptide — a chain of seven amino acids — originally developed in Russia for neurological research. Keep it frozen at around −20 °C until you are ready to work with it. Always check the certificate of analysis (COA) for purity above 98% before you work with any batch.
What Is Semax Peptide
Semax is a synthetic analogue of a fragment of ACTH, a naturally occurring hormone. Researchers isolated that fragment and modified it to produce a more stable, longer-lasting compound than the original. The result is a seven-amino-acid chain — which is why it is called a heptapeptide.
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The terminal Pro-Gly-Pro addition is the modification that distinguishes Semax from the natural ACTH fragment and gives it greater resistance to enzymatic breakdown.
Most published research on Semax comes from Russian and Eastern European institutions. Western research is less extensive, so treat the available evidence base accordingly.
Semax Powder Storage
Store lyophilised — freeze-dried — Semax powder at −20 °C. That is a standard lab freezer, not a frost-free domestic freezer that cycles temperatures. Frost-free freezers repeatedly warm and re-cool to prevent ice build-up. Those temperature swings accelerate breakdown of sensitive peptides.
A few practical rules for powder storage:
- Keep it in the original sealed vial. Moisture and oxygen are the main enemies.
- Use a desiccant if you store multiple vials together.
- Let the vial warm to room temperature before you open it. Cold glass pulls moisture from the air the moment it is exposed. Water getting into a lyophilised peptide starts breaking it down immediately.
- Do not open the vial repeatedly. If you are not working with it yet, leave the seal intact.
Properly stored lyophilised Semax is typically stable for up to 24 months at −20 °C. The COA should state the recommended storage condition and the expiry date.
Semax Storage After Reconstitution
Once the powder is reconstituted, the rules change. Reconstituted Semax should be kept at 2–8 °C — a standard laboratory refrigerator — and used within four weeks.
In solution, the peptide chain is exposed. Water slowly breaks the bonds between amino acids, and the peptide degrades progressively. Bacteriostatic water, which contains 0.9% benzyl alcohol, slows microbial growth but does not stop chemical breakdown. The clock starts the moment you add liquid.
A few handling notes for reconstituted Semax:
- Use bacteriostatic water rather than plain sterile water. The preservative extends the usable window.
- Add the water slowly down the side of the vial. Do not inject it directly onto the powder cake, and do not vortex or shake. Roll the vial gently until the powder dissolves.
- Label the vial with the reconstitution date.
- Do not freeze reconstituted Semax. Freezing can cause aggregation — clumping — that reduces the reliability of the preparation for analytical work.
Semax COA and Purity
A Semax COA (certificate of analysis) is a document from an independent laboratory that records what is actually in the vial. The key figure to check is purity.
Semax purity should be at least 98% by HPLC — high-performance liquid chromatography, a method that physically separates the components of a sample and measures how much of each is present. Anything below 98% means a meaningful fraction of what you are working with is not Semax, which affects reproducibility in research settings.
A credible COA will include:
| Field | What to look for |
|---|---|
| Method | HPLC for purity, MS (mass spectrometry) to confirm the correct molecular weight |
| Purity result | ≥ 98% |
| Molecular weight | 813.94 g/mol for Semax |
| Appearance | White to off-white powder |
| Testing lab | A named third-party laboratory, not the manufacturer itself |
| Batch number | Should match the number on your vial |
The batch number is the detail most people overlook. If the COA batch number does not match your vial, the document is not telling you anything about what you actually received.
Regulatory Landscape
Semax occupies a complex regulatory position in many markets. It is not approved by the FDA for any use in the United States, and it is not authorised as a medicine in most Western countries. In Russia it has a longer history of institutional research, which is why the bulk of published literature originates there.
In research and analytical contexts, Semax is handled as a research chemical. Laboratories working with it are expected to maintain documentation — including COAs, storage logs and chain-of-custody records — that demonstrates the material is being used for in vitro or analytical purposes only.
Regulatory interest in synthetic peptides has grown in recent years. Suppliers and researchers alike should stay current with applicable rules in their jurisdiction, as the classification of research chemicals can change without much notice.
Practical Summary
Semax is a seven-amino-acid synthetic peptide used in laboratory and analytical research. Store the powder at −20 °C in a sealed vial, away from moisture. Once reconstituted, refrigerate at 2–8 °C and work with it within four weeks. Before use, verify the COA — confirm purity is at least 98% by HPLC, check that the molecular weight is 813.94 g/mol, and make sure the batch number matches your vial.
NXT Labs products are sold strictly as research chemicals for in vitro research, laboratory testing and analytical purposes only, and are not intended for use in any human or animal application.
NXT Labs supplies research peptides for laboratory use. Browse the full range or view current Certificates of Analysis.
