How Long Does Snap-8 Last? Storage Before and After Mixing
Lyophilised Snap-8 keeps for 4 years or more sealed, dry and frozen at −20 °C on one supplier’s data sheet; 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 Snap-8 in bacteriostatic water, so that window is the general peptide guidance. Its eight residues include a methionine, a glutamine and an aspartic acid, so a mixed vial is kept especially well protected from light and air, and it is never frozen.
Findings
- Snap-8 is acetyl octapeptide-3, Ac-Glu-Glu-Met-Gln-Arg-Arg-Ala-Asp-NH2, with a formula weight of 1,075.2 (Cayman Chemical data sheet).
- The same sheet rates the solid at −20 °C with stability of at least 4 years.
- It lists solubility of about 10 mg/mL in PBS at pH 7.2, and advises purging stock solvent with an inert gas.
- Methionine is an oxidation-prone residue and glutamine can deamidate, two of the commonest ways peptides change in solution (Manning et al., Pharm Res, 2010).
- Aspartic acid can isomerise through a ring intermediate, though far more slowly than asparagine (Geiger and Clarke, J Biol Chem, 1987).
How long does Snap-8 powder last?
The data sheet from Cayman Chemical gives the solid a storage temperature of −20 °C and stability of at least 4 years. The sheet gives no fridge figure, so the fridge is for near-term work and the freezer for longer holds. Moisture is the main enemy of a freeze-dried cake: it lets the same reactions that happen in solution start in the solid. The 10 mg vial is kept capped and boxed, and a cold vial is brought to room temperature before opening so that condensation does not form on the powder.
How long does Snap-8 last after mixing?
At 2 to 8 °C, dark and accessed only through a swabbed stopper, mixed Snap-8 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 Snap-8 reconstitution page has the calculator for the 10 mg vial.
What the sequence says about stability
Snap-8 dissolves in water-based solutions; the supplier lists about 10 mg/mL in buffer. Its storage sensitivities are chemical rather than physical, and no study has measured them for Snap-8 itself, so the picture comes from its residues.
The methionine at position 3 is the main one. Oxidation of methionine is one of the commonest ways peptides change in solution (Manning et al., 2010). The supplier’s advice to purge stock solvent with an inert gas, which removes dissolved oxygen, points the same way. The glutamine at position 4 can deamidate, slowly. The aspartic acid at the end can form a ring intermediate and reopen as isoaspartate, a route that runs about 34 times more slowly for aspartic acid than for asparagine in model peptides (Geiger and Clarke, 1987).
The acetyl group helps. A free glutamic acid at the start of a chain can close into pyroglutamic acid (Chelius et al., Anal Chem, 2006); in Snap-8 the first glutamic acid is acetylated, which blocks that ring closure. That last point is an inference from the chemistry, not a measured result. Snap-8 also has no cysteine, tryptophan or asparagine. The practical result is the same window as most peptides, with extra attention to light, a tight stopper and gentle swirling rather than shaking, which works air into the solution.
How long does Snap-8 last at room temperature?
There is no published figure for Snap-8 in bacteriostatic water at room temperature. The supplier sheet does not recommend keeping a plain aqueous buffer solution for more than one day; it gives no data behind that advice, and it describes an unpreserved bench solution rather than a sealed, cold vial. A mixed vial is taken out of the fridge only for handling, because warmth speeds the oxidation above.
Can Snap-8 be frozen?
The powder can, and the supplier’s only figure, at least 4 years, is a −20 °C figure. No supplier figure was found for frozen Snap-8 solution. A working vial should not be frozen and thawed repeatedly, since freeze-thaw cycles aggregate peptides in solution.
How can you tell mixed Snap-8 has degraded?
- Yellowing or any tint. Mixed Snap-8 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 itself is invisible, which is why the time window applies even to a vial that still looks perfect.
Snap-8 storage at a glance
| State | Where | How long |
|---|---|---|
| Powder, sealed | −20 °C, dry | At least 4 years (supplier data sheet) |
| Powder, sealed | 2 to 8 °C, fridge | No published figure; near-term only |
| Mixed with bacteriostatic water | 2 to 8 °C, dark | 8 to 12 weeks, fading from week 6 to 8 (store guidance) |
| 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.
Vistara Labs supplies Snap-8 as a laboratory research material. The windows on this page describe how long the peptide stays in good condition.
Frequently asked questions
How long does Snap-8 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 Snap-8 last at room temperature?
No published figure exists for Snap-8 in bacteriostatic water at room temperature. A mixed vial is kept in the fridge and taken out only for handling.
Can you freeze Snap-8?
Yes as powder: one supplier rates it at least 4 years at −20 °C. A working vial of solution should not go through repeated freeze-thaw cycles.
Does Snap-8 go bad?
Yes. Its methionine oxidises slowly in solution, faster with warmth and light, and its glutamine and aspartic acid change more slowly still. Cloudiness, particles, a tint or gel mean it has degraded.
Does Snap-8 store the same way as Argireline?
Very nearly. Snap-8 is Argireline’s six residues, Ac-EEMQRR-NH2, plus alanine and aspartic acid, so it carries the same methionine and glutamine, and light and air are the main concerns for both.
Handling windows: Vistara Labs, October 2026. Sources: Cayman Chemical. Acetyl Octapeptide-3, item 27260, product information sheet: sequence, storage, stability and solubility. PDF. Manning MC et al. Stability of protein pharmaceuticals: an update. Pharm Res. 2010. PMID 20143256. Geiger T, Clarke S. Deamidation, isomerization, and racemization at asparaginyl and aspartyl residues in peptides. J Biol Chem. 1987. PMID 3805008. Chelius D et al. Formation of pyroglutamic acid from N-terminal glutamic acid in immunoglobulin gamma antibodies. Anal Chem. 2006. PMID 16579622. Blanes-Mira C et al. A synthetic hexapeptide (Argireline) with antiwrinkle activity. Int J Cosmet Sci. 2002. PMID 18498523.
More on this: How Long Do Peptides Last After Mixing?
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.
