Lyophilized (freeze-dried powder) - the form peptides ship in, and the most stable. With virtually no water present, the reactions that break peptides down (hydrolysis, oxidation, deamidation) occur very slowly. Stored sealed and protected from light, lyophilized peptides remain stable roughly 12–24 months refrigerated at 2–8°C, and longer frozen at −20°C.

Reconstituted (mixed into liquid) - once a diluent is added, the stability clock starts. Water reactivates the degradation pathways, so reconstituted peptides must be refrigerated at 2–8°C, never frozen, and used within a defined window. A common benchmark is around 28 days for preserved multi-dose vials - a figure drawn from standard pharmacy compounding practice (USP Chapter <797> beyond-use dating), not a peptide-specific guarantee. Some robust peptides tolerate longer; more sensitive ones less.

• Heat & temperature swings - the single biggest factor. Higher temperatures accelerate every degradation reaction; keep storage cold and consistent, away from heat sources.
• Light & UV - breaks down molecular structure. Keep vials in their packaging or a dark container.
• Freeze-thaw cycles - repeated freezing and thawing causes molecular breakdown. Freeze only if necessary, and only once; never freeze a reconstituted vial.
• Contamination - non-sterile handling introduces bacteria and unwanted variables. Sterile technique is essential once a vial is opened or reconstituted.

• Keep storage cold and consistent - avoid leaving vials at room temperature or near heat.
• Protect from light - store in original packaging or a dark container.
• Never freeze a reconstituted vial - ice crystal formation damages the peptide.
• Swirl, never shake - shaking creates foam and mechanical stress that can break peptide bonds.
• Label every vial with its reconstitution date - reconstituted peptides often show no visible change until degradation is advanced.
• Minimize air exposure - each opening exposes the contents to oxygen; limit unnecessary openings.

Stability depends partly on a peptide's amino-acid composition. Sequences containing methionine, cysteine, or tryptophan, or those with disulfide bonds, are more prone to oxidation and can degrade faster without extra care. This is one reason handling guidance is best given per-compound rather than as a single universal rule - and why Vivre's handling instructions are specific to what you're dispensed.

Reconstitution is the step of mixing the lyophilized powder with a sterile diluent - typically bacteriostatic water, which contains a small amount of preservative (benzyl alcohol) that allows a vial to be used for multiple doses. Adding the diluent is what starts the stability clock described above.

Because the diluent volume directly determines your dose, Vivre provides reconstitution specifics - exact volumes, concentration, and preparation - as part of your physician-guided onboarding, not as general web content. This keeps dose preparation where it belongs: with your supervising clinician, tied to your specific protocol.