How Long Does Kisspeptin Last? Storage Before and After Mixing

Lyophilised kisspeptin-10 keeps for a year or more sealed, dry and frozen; once mixed with bacteriostatic water it 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. No published stability study covers kisspeptin-10 in a sterile solution, so that window is the general peptide guidance. The published figures measure enzymes in plasma, a different question. Its tryptophan and two asparagines make light, warmth and time the main concerns for a mixed vial, and a working vial is never frozen.

Findings

• Kisspeptin-10 is the last 10 amino acids of kisspeptin-54, YNWNSFGLRF-NH2, also called metastin 45-54 (Liu et al., J Chromatogr B, 2013).
• A chemical supplier’s data sheet rates the powder at 2 years at −80 °C and 1 year at −20 °C, sealed away from moisture and light.
• The same sheet gives a stock solution 1 month at −20 °C and 6 months at −80 °C.
• In rat plasma, kisspeptin-10 had a breakdown half-life of 6.8 minutes at 4 °C, with the first tyrosine clipped off (Liu et al., 2013). That is enzyme activity in blood, not a measure of a sterile vial.
• Tryptophan at position 3 is an oxidation-prone residue, and asparagine at positions 2 and 4 can deamidate.

How long does kisspeptin powder last?

The data sheet from MedChemExpress gives kisspeptin-10 powder 2 years at −80 °C and 1 year at −20 °C, stored sealed and away from moisture and light. Moisture is the main enemy of a freeze-dried cake: it lets the same reactions that happen in solution start in the solid. The Kisspeptin 10 mg vial is kept capped and boxed, in the fridge for near-term work or the freezer for longer holds, and a cold vial is brought to room temperature before opening so that condensation does not form on the powder.

How long does kisspeptin last after mixing?

At 2 to 8 °C, dark and accessed only through a swabbed stopper, mixed kisspeptin-10 lasts 8 to 12 weeks, with quality fading from around week 6 to 8. That is the general row in how long peptides last after mixing. The kisspeptin reconstitution page has the calculator for the 10 mg vial.

What the sequence says about stability

Kisspeptin-10 dissolves in water; the supplier sheet lists solubility of 10 mg/mL with ultrasound. Oxidation is one of the major ways peptides and proteins degrade in storage, light can drive it, and tryptophan and tyrosine are among the residues most open to it (Li et al., Biotechnol Bioeng, 1995). Kisspeptin-10 has a tyrosine at position 1 and a tryptophan at position 3. Asparagine is the other hot spot. In model peptides it forms a ring intermediate and deamidates, fastest when glycine follows it and much slower when a bulky residue does (Geiger and Clarke, J Biol Chem, 1987). Here the first asparagine is followed by tryptophan and the second by serine. Against that, kisspeptin-10 has no methionine or cysteine, and its amidated end removes a free acid group. The result is the usual window, with extra care over light and gentle swirling rather than shaking.

What the frozen-solution figures mean

The supplier’s 1 month at −20 °C and 6 months at −80 °C apply to stock solutions frozen once and kept sealed, a laboratory practice for single-use aliquots. They are not a reason to freeze a working vial that will be thawed and opened again.

How long does kisspeptin last at room temperature?

There is no published figure for kisspeptin-10 in a sterile solution at room temperature. The 2.9 minute half-life at 25 °C reported by Liu and colleagues was measured in rat plasma, where enzymes do the cutting, so it says nothing about a sealed vial. Serum enzymes inactivate it just as fast (Asami et al., Bioorg Med Chem Lett, 2012). A mixed vial leaves the fridge only for handling, because warmth speeds the reactions above.

Can kisspeptin be frozen?

The powder can, and the supplier’s longest figure, 2 years, is a freezer figure. Single-use aliquots of solution can be frozen once. A working vial should not be frozen and thawed repeatedly, since freeze-thaw cycles aggregate peptides in solution.

How can you tell mixed kisspeptin has degraded?

• Yellowing or any tint. Mixed kisspeptin-10 should be clear and colourless.
• Cloudiness that does not clear within 10 to 15 minutes of mixing, or that appears later.
• Particles or sediment.
• Gel or thickening.

Oxidation and deamidation are invisible, so the time window applies even to a vial that looks perfect.

How long does kisspeptin nasal spray last?

The Kisspeptin Nasal Spray arrives ready-mixed in a sealed metered pump, so there is nothing to reconstitute. Once opened it is kept at 2 to 8 °C, upright, capped and in the dark, never frozen, and it lasts as long as its label allows. The 8 to 12 week vial window does not carry over, because a spray is a different preparation. Date the bottle on the day it is first opened, and discard it if the solution turns cloudy, shows particles or changes colour. The full routine is in how to store a peptide nasal spray.

Kisspeptin storage at a glance

State	Where	How long
Powder, sealed	−20 °C / −80 °C, dry, dark	1 year / 2 years (supplier data sheet)
Powder, sealed	2 to 8 °C, dry, dark	No supplier figure found; near-term holds
Mixed with bacteriostatic water	2 to 8 °C, dark	8 to 12 weeks, fading from week 6 to 8 (store guidance)
Solution aliquots, frozen once	−20 °C / −80 °C	1 month / 6 months (supplier data sheet)
Mixed, room temperature	Handling only	No published figure

Certificates of analysis are on the lab reports page, and every order ships from within Canada by Canada Post Xpresspost.

Frequently asked questions

How long does kisspeptin last in the fridge after mixing?

Under Vistara Labs’ handling guidance, 8 to 12 weeks at 2 to 8 °C in the dark, with quality fading from around week 6 to 8.

How long does kisspeptin last at room temperature?

No published figure exists for kisspeptin-10 in a sterile solution at room temperature. A mixed vial is kept in the fridge and taken out only for handling.

Can you freeze kisspeptin?

Yes as powder: one supplier rates it at 1 year at −20 °C and 2 years at −80 °C. Solution can be frozen once as single-use aliquots, but a working vial should not go through repeated freeze-thaw cycles.

Does kisspeptin go bad?

Yes. Its tryptophan oxidises and its asparagines deamidate slowly in solution, faster with warmth and light. Cloudiness, particles, a tint or gel mean it has degraded.

Why does kisspeptin break down in minutes in plasma studies but keep for weeks in a vial?

Plasma contains enzymes that clip the peptide, starting with its first tyrosine. A sterile vial of bacteriostatic water has no such enzymes, so only slow chemical changes set the clock there.

Related reading. What is kisspeptin?, kisspeptin reconstitution, Kisspeptin Nasal Spray and bacteriostatic water explained.

Handling windows: Vistara Labs, October 2026. Sources: Liu Z et al. LC-MS/MS quantification of a neuropeptide fragment kisspeptin-10 (NSC 741805) and characterization of its decomposition product and pharmacokinetics in rats. J Chromatogr B Analyt Technol Biomed Life Sci. 2013. PMID 23524040. Asami T et al. Serum stability of selected decapeptide agonists of KISS1R using pseudopeptides. Bioorg Med Chem Lett. 2012. PMID 22975302. Geiger T, Clarke S. Deamidation, isomerization, and racemization at asparaginyl and aspartyl residues in peptides. J Biol Chem. 1987. PMID 3805008. Li S, Schöneich C, Borchardt RT. Chemical instability of protein pharmaceuticals: mechanisms of oxidation and strategies for stabilization. Biotechnol Bioeng. 1995. PMID 18623513. MedChemExpress. Kisspeptin-10, human, HY-P0254, product data sheet: sequence, solubility and storage. PDF.

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