How Long Does Semax Last? Storage Before and After Mixing
Lyophilised Semax keeps best sealed, cold and dark, and once mixed with bacteriostatic water it lasts 8 to 12 weeks at 2 to 8 °C, with quality slowly fading from around week 6 to 8. A mixed vial does not belong at room temperature, should not be frozen and refrozen, and is kept out of light. The registered Semax nasal drops sold in Russia carry the same instructions in their own labelling: cold storage and protection from light. The ready-mixed Semax Nasal Spray follows the same cold rules as a mixed vial.
Findings
- Semax is a seven-amino-acid peptide, Met-Glu-His-Phe-Pro-Gly-Pro: a fragment of ACTH (the 4 to 7 sequence) with a Pro-Gly-Pro tail added.
- The registered 0.1% nasal drops are a water solution preserved with methylparaben, labelled for cold storage protected from light, with a 2-year shelf life.
- In rat blood and serum, breakdown starts at the first two residues, Met and Glu, through an aminopeptidase, and Semax was more stable than ACTH(4-10) against the other enzymes involved (1991).
- No published stability study of Semax in bacteriostatic water was found, so the 8 to 12 week mixed window is Vistara Labs’ general peptide guidance, not a compound-specific figure.
How long does lyophilised Semax last?
As a dry powder, Semax has almost nothing to react with, which makes the sealed vial its most durable form. Keep it in the fridge at 2 to 8 °C for everyday storage, or in the freezer for long-term storage, in its box and away from light. Let a cold vial reach room temperature before opening the cap seal, so condensation does not form on the cake. A short spell at room temperature, such as the time a parcel spends in transit, is not a concern for the powder. The general rules are in how to store peptides.
How long does Semax last after mixing?
Under Vistara Labs’ handling guidance, mixed Semax lasts 8 to 12 weeks at 2 to 8 °C, the same window as most peptides in how long peptides last after mixing. That assumes the vial was mixed with bacteriostatic water, kept in the main body of the fridge, stored upright in the dark, and opened only through a swabbed stopper. Write the mixing date on the vial. The Semax reconstitution page has the calculator for water volume and concentration.
| Form | Where to keep it | How long |
|---|---|---|
| Lyophilised vial, sealed | Fridge, or freezer for long-term storage; dark | Its most stable form |
| Vial mixed with bacteriostatic water | 2 to 8 °C, upright, dark | 8 to 12 weeks, fading from week 6 to 8 |
| Ready-mixed nasal spray | 2 to 8 °C, upright, capped | Kept cold from arrival |
| Mixed solution at room temperature | Not a storage condition | Back in the fridge after use |
What breaks Semax down?
Semax starts with methionine, one of the amino acids most prone to oxidation in solution. Oxygen, warmth and light all speed that reaction, which is why a mixed vial is kept cold, capped and dark. In biological fluids the main threat is enzymes: in a 1991 study of rat blood and serum, roughly a third to a half of the serum’s degrading activity came from a bestatin-sensitive aminopeptidase that removed Met and then Glu from the front of the chain, leaving relatively stable fragments, while Semax resisted the other enzymes better than ACTH(4-10) did (Potaman et al., Biochem Biophys Res Commun, 1991). A sterile, sealed vial keeps enzymes and microbes out; that is the reason for swabbing the stopper before every access.
What does the registered Semax product show?
Semax is registered in Russia as nasal drops. The 0.1% product contains 1 mg of the heptapeptide and 1 mg of methylparaben per millilitre of purified water (Vidal drug reference). Its reference listing gives storage at 8 to 10 °C, protected from light, with a 2-year shelf life (RLS drug encyclopedia), and the Vidal entry lists 2 to 8 °C; the 1% instruction says not above 10 °C, never frozen, with the cap closed tightly (Semax 1% instruction). That tells you Semax can hold up in water for a long time when it is formulated for it and kept cold. A research vial mixed with bacteriostatic water is not that formulation, so the shorter handling window applies.
How can you tell mixed Semax has degraded?
Semax dissolves to a clear solution. Discard it, whatever the date, if it turns cloudy and stays that way, shows strands, flakes or particles, or develops a yellow tint. Oxidation of methionine does not show up as a colour change, so a clear solution past 12 weeks is still past its window. More on what visible changes mean is in why peptides gel or go cloudy.
Travelling with Semax
Every order ships from within Canada by Canada Post Xpresspost, and the lyophilised vial travels without refrigeration. A mixed vial or a spray that has to travel goes in an insulated bag with a cold pack, wrapped so the bottle never touches the pack directly, because freezing is as damaging as heat. Back in the fridge on arrival.
Semax nasal spray storage
The Semax Nasal Spray arrives ready-mixed in a sealed metered pump that delivers 0.175 mL per press, in a 10 mg and a 20 mg bottle; the Selank + Semax Nasal Spray combines both peptides in one bottle. Because it is already a solution, it is kept like a mixed vial: in the fridge, upright, capped and out of light, and never frozen. Priming and day-to-day handling are in how to store a peptide nasal spray, and the press count per bottle is in how many sprays are in a peptide nasal spray.
Vistara Labs supplies Semax as a laboratory research material. The windows on this page describe how long a solution stays in good condition; they are not instructions for any other use.
Frequently asked questions
How long does Semax last in the fridge?
Mixed with bacteriostatic water, Semax lasts 8 to 12 weeks at 2 to 8 °C under Vistara Labs’ handling guidance, with quality slowly fading from around week 6 to 8. The sealed lyophilised vial lasts longer.
How long does Semax last at room temperature?
The lyophilised powder tolerates short periods at room temperature, such as transit. A mixed solution is not stored at room temperature: Semax begins with methionine, which oxidises faster as temperature rises.
Can you freeze Semax?
The sealed lyophilised vial can go in the freezer for long-term storage. A mixed vial that will be opened again should not be frozen, because freeze-thaw cycles damage peptides in solution.
Does Semax go bad?
Yes, slowly. Mixed Semax loses quality from around week 6 to 8 in the fridge. Discard it sooner if it turns cloudy, shows particles or changes colour.
How should Semax nasal spray be stored?
In the fridge at 2 to 8 °C, upright, capped and out of light, never frozen. The registered Semax nasal drops are also labelled for cold storage protected from light.
Handling windows: Vistara Labs, October 2026. Sources: Potaman VN, Alfeeva LY, Kamensky AA, Levitzkaya NG, Nezavibatko VN. N-terminal degradation of ACTH(4-10) and its synthetic analog semax by the rat blood enzymes. Biochem Biophys Res Commun. 1991. PMID 1851003. Semax nasal drops 0.1%, composition and storage, Vidal drug reference (vidal.ru). Semax solution 0.1%, storage and shelf life, RLS drug encyclopedia (rlsnet.ru). Semax nasal drops 1%, instructions for use (medi.ru).
More on this: Semax Peptide: What the Research Actually Covers.
All products supplied by Vistara Labs are intended for laboratory research use only. They are not drugs, are not approved for human or veterinary use, and are not intended to diagnose, treat, cure or prevent any condition. Nothing on this page constitutes medical advice or guidance for use in humans.
