PeptideSynthNJ said:

The distinction that matters is unopened versus in use.

Storage best practices for compounded storage and cold:

• Unreconstituted lyophilized powder: refrigerate (36-46°F), good for 12+ months
• Reconstituted vials: refrigerate, use within 28 days
• Pre-filled pens: refrigerate until first use, then room temp OK for 28 days
• Never freeze reconstituted peptides — ice crystals damage the protein
• Protect from light — store in original box or wrap in foil

When in doubt, refrigerate. Temperature abuse is the #1 cause of reduced potency in compounded peptides.

PeptideSynthNJ said:

The distinction that matters is unopened versus in use.

I read this differently from PeptideSynthNJ, on substance rather than tone. Freezing is the one to avoid, and freeze-thaw more so. Ice-crystal formation and the concentration changes at the phase boundary drive aggregation, and aggregated peptide does not recover on thawing. A vial that has been frozen and thawed is not rescued by returning it to the fridge.

julia.endo said:

Freezing is the one to avoid, and freeze-thaw more so.

Storage question about storage and cold: my pen was left out of the fridge for 6 hours. Is it still good?

Per the manufacturer, both Ozempic and Wegovy pens can be stored at room temp (up to 86°F) for up to 28 days after first use. So yes, it should be fine as long as it wasn't exposed to extreme heat.

kate.chem said:

Storage best practices for compounded storage and cold: Unreconstituted lyophilized powder: refrigerate (36-46°F), good for 12+ months Reconstituted…

Same pattern here, and in the same order.