Is room temperature an acceptable storage condition for lyophilised retatrutide?

Stated plainly: room temperature · retatrutide.

I am asking for verification rather than opinion, ideally with something I can read myself.

It is possible the evidence exists and I am searching for the wrong term.

What would count as evidence here, and does it exist?

room temperature is above the refrigerated band, and how far above is the whole answer. Room temperature is not a number, so take the pharmacopoeial 20–25 °C and its 22.5 °C midpoint: 17.5 kelvin above the 5 °C middle of a 2–8 °C refrigerator. The ten-degree rule of thumb — degradation rate roughly doubling per 10 K — puts that at about 3.4 times the refrigerated rate. It is an order-of-magnitude statement about a rate, not a shelf life, and the top of the 20–25 °C band runs about 1.4 times faster than the bottom of it. Lyophilised material tolerates this far better than solution does, which is why it is shipped that way, but "tolerates" is a statement about weeks and the vial is being asked about months. Log the excursion rather than guess at it. Nothing here is medical advice, and research-use-only material is not approved for human use.

Answer first: dry, cold, dark and still, with the lot code where you can still read it in a year.

Keep vials in their original carton or in an opaque box. Light exposure matters for tryptophan-containing sequences and for anything with a chromophore, and a closed box is free.

Degradation pathway by condition

Keep the certificate with the vial, physically or as a photograph filed under the lot code. A vial without a traceable certificate is an anonymous vial regardless of where it came from.

The 28-day in-use period for preservative-containing multi-dose preparations is printed on the diluent labelling and is a long-standing pharmacy convention.

A printed expiry on research-grade material has no stability programme behind it.

Minus eighty buys very little over minus twenty for a dry solid.

The short version: powder in the freezer or fridge, reconstituted in the fridge for weeks, and never anything on a windowsill.

Let a refrigerated or frozen vial equilibrate to room temperature before opening, so humid air does not condense water onto a cold cake.

The underlying point is that reconstituted with a preservative-containing diluent: refrigerated, conventionally treated as usable for about 28 days from first entry. Without a preservative, single use and discard.

Residual moisture is the dominant determinant of solid-state stability, which is why desiccants accompany lyophilised material.

Keep the desiccant with the vial and the certificate with the lot code.

edited 21 Feb 2025 by tamsin_wray — added the citation requested in comments

Start with the physical state, because lyophilised and reconstituted material have completely different storage answers.

Lyophilised powder: refrigerated at two to eight degrees for months, frozen at minus twenty for longer. The gain from minus eighty over minus twenty is small for a dry solid and is not usually worth the arrangement.

Store with the desiccant sachet if one was supplied, inside the secondary container rather than loose in a drawer. Residual moisture is the dominant variable in solid-state stability.

Appearance does not indicate stability; a normal-looking cake can be substantially degraded.

Equilibrate before opening or you condense water into the cake.