How to store peptides depends on their state: the powder (lyophilisate) is robust and likes it dry, cool and dark; a reconstituted (mixed) solution belongs in the fridge and only keeps for a limited time. Keep the two cases apart - the rules differ.

Storing powder (lyophilisate) - how long does it last?

The freeze-dried powder (technical term: lyophilisate) is very stable but strongly water-attracting (hygroscopic). Store it airtight with a desiccant, protected from light. In the fridge (2-8 °C), well sealed and dry, the powder usually stays stable for several months up to about a year (depending on the peptide); for longer storage it belongs in the freezer (−18 °C or colder), where it often stays stable for years. How to freeze it properly is shown in the freezing guide.

Storing a reconstituted (mixed) solution

Once you have reconstituted (mixed) with BAC water, store the vial in the fridge at 2-8 °C, in the dark, and usually use the solution within about 21-30 days. Do not keep it in the fridge door (temperature swings). Details on BAC water and shelf life are in the FAQ.

A reconstituted (mixed) solution must never go in the freezer: ice crystals and freeze-thaw cycles can destroy the peptide. Freezing is only for the powder - see freezing.

Which peptides are how sensitive is shown in the peptide overview.

Note: Educational information, not medical advice. Many of these substances are experimental and not approved for human use.

Step by step

Step 1

Dry and airtight

Powder (lyophilisate) is hygroscopic. Keep it in an airtight container with a desiccant sachet so no moisture gets in.

Step 2

Cool and dark

Protect it from light and heat and store the vial upright. In the fridge (2-8 °C) the well-sealed, dry powder usually keeps for several months up to about a year. Pick a spot with stable 2-8 °C: not right at the back (it can freeze there) and not in the door (temperature swings when opened).

Peptides are light-sensitive - opaque insulin/medication cooler cases protect from light and keep things tidy; they are cheap on online marketplaces (e.g. a search for "vial case" on AliExpress).

Step 3

Freeze powder for the long term

For long-term storage the powder belongs in the freezer (−18 °C or colder) - it often stays stable for years. See the freezing guide.

Step 4

Reconstituted goes in the fridge

Store the reconstituted solution upright at a stable 2-8 °C, dark. Same rule: not right at the back (risk of freezing) and not in the door (temperature swings when opened).

Step 5

Mind the use-by window

Use a reconstituted solution within about 21-30 days. Label it with the date to keep track.

Or use our Injection Manager: when logged in you can record the mix date, amount and usage per vial.

Storing peptides: powder vs. reconstituted solution