How to Store Reconstituted Peptides

Storing a reconstituted vial well comes down to a few neutral, practical points. This page describes general handling only — always follow the guidance for your specific product.

Before reconstitution

Dry, freeze-dried powder is the stable form, which is why peptides ship that way. Unmixed vials are typically kept cool and out of light per the product's instructions, and are far more forgiving than a solution.

After reconstitution

Once in liquid, a peptide is generally more delicate. Common, widely-described practice is to keep the solution refrigerated and out of direct light, and to avoid freezing the solution, since freeze-thaw cycles can degrade some peptides. The benzyl alcohol in bacteriostatic water inhibits microbial growth, which is what makes a multi-use vial practical over a period.

Handling

Label the vial with the date you reconstituted it and the concentration, so you're not guessing later.
Swirl, don't shake. Add the water gently down the vial wall and swirl to dissolve; vigorous shaking is commonly avoided.
Wipe the stopper with an alcohol swab before each draw.

Follow the product guidance

Exact temperatures and how long a vial remains usable vary by peptide and supplier, so the instructions that come with your product take precedence over any general rule of thumb. This page is informational only and isn't medical or pharmaceutical advice.

Open the reconstitution calculator

Frequently asked questions

Do reconstituted peptides need refrigeration?

Once in solution, peptides are commonly kept refrigerated rather than at room temperature. Storage requirements vary by peptide and product, so follow the guidance supplied with your specific vial.

How long does a reconstituted peptide last?

This varies widely by the specific peptide, the diluent, and storage conditions, so there's no universal number. Bacteriostatic water's preservative is what allows multi-use over a period rather than single use. Always follow the product's own guidance.

Can you freeze a reconstituted peptide?

Freezing a peptide that's already in solution is generally discouraged, as freeze-thaw cycles can degrade some peptides. The dry, pre-reconstitution powder is sometimes stored frozen. Follow the guidance for your product.

Why does bacteriostatic water help with storage?

Its benzyl alcohol preservative inhibits bacterial growth, which is what makes a multi-use vial practical over a period of days rather than a single use. Sterile water and plain saline have no preservative.