Storing peptides: sealed, mixed and on delivery

Sealed, lyophilized vials

Freeze-drying removes the water from a product after it is frozen, and the FDA notes that products are made in lyophilized form because they are unstable in solution^[2]. The dry cake is the stable form, which is why peptides ship as powder. Primara Labs' own instruction for sealed vials is to keep them refrigerated at 2 to 8 °C, away from light^[1]. That is Primara Labs' instruction, not a third-party standard. For storage beyond the refrigerator, such as a freezer for long holding, follow the lab report or product label for that compound.

Reconstituted vials

Once reconstituted, keep the vial in the refrigerator at 2 to 8 °C and write the date and concentration on it (see how to reconstitute a peptide vial). How long a reconstituted peptide stays usable depends on the compound, so follow the lab report or product label. Two published reference points show how much that varies. CDC guidance, citing USP chapter 797, is that an opened multi-dose vial is discarded within 28 days unless the manufacturer states another date^[3]. The US label for one lyophilized peptide medicine, tesamorelin, says to discard the mixed solution 7 days after mixing^[4]. Neither figure is a stability claim for any peptide in the Primara Labs catalogue.

Light

Keep vials in their box or a closed container in the refrigerator rather than exposed on a shelf. Primara Labs' instruction is storage away from light^[1], and the tesamorelin label tells users to keep the vial in the original box to protect it from light^[4].

Freezing

Whether a peptide tolerates freezing depends on the compound and its formulation, so follow the lab report or product label. The tesamorelin label, for example, says not to freeze the product^[4]. Repeated freezing and thawing is the pattern most worth avoiding; the freeze-thaw guide explains why and how to split stock so a vial is not thawed more than once.

When the parcel arrives

Cold chain to your door. Insulated packaging with a cold pack on every order, Metro Manila or provincial. Provincial parcels leave only on the dispatch days published on the delivery page so a vial never sits in a courier hub over a weekend.

1. Open the parcel as soon as it arrives rather than leaving it in a warm room or a vehicle.
2. Take the vials out of the insulated cold-chain pouch.
3. Check each label and batch number against the order (reading your vial label) and check that the powder is intact.
4. Put the sealed vials straight into the refrigerator at 2 to 8 °C, in their box or a closed container.
5. If anything arrived damaged or does not match, message on WhatsApp before reconstituting any vial.

The unboxing checklist covers each check in more detail, and storing peptides in Philippine heat covers brownouts and transport.