Proper storage is the difference between a peptide that retains full potency and one that silently degrades into uselessness. Peptides are sensitive to temperature, light, moisture, and mechanical stress. This guide covers exactly how to store them at every stage - from arrival to the last injection.
Peptides exist in two fundamentally different storage states, and the rules change significantly between them:
| Property | Lyophilised (Powder) | Reconstituted (Liquid) |
|---|---|---|
| Optimal temp | −20°C (freezer) | 2–8°C (refrigerator) |
| Acceptable temp | 2–8°C (fridge) for weeks | Room temp for hours only |
| Shelf life | 12–24+ months (frozen) | Up to 30 days (refrigerated) |
| Light sensitivity | Moderate | High |
| Freeze-thaw safe? | Yes (it's already dry) | No - avoid |
| Main degradation risk | Moisture absorption | Hydrolysis, oxidation, bacteria |
Lyophilised peptides are freeze-dried into a stable powder form. In this state, they're relatively robust, but proper storage still matters.
Shipping note: Peptides shipped at ambient temperature are fine. Lyophilised peptides are stable enough to survive 3–5 days in transit without significant degradation. Once they arrive, move them to the freezer or refrigerator promptly.
UV light causes photo-oxidation of amino acid residues, particularly tryptophan, tyrosine, and methionine. Keep vials in their original packaging or store them in an opaque container. A freezer with a solid door (not glass) provides inherent light protection.
This is the biggest enemy of lyophilised peptides. The entire point of lyophilisation is to remove water; if moisture is reabsorbed, degradation reactions restart. Keep vials sealed with their original crimped caps. If you're storing opened vials, use parafilm around the cap and consider placing them in a sealed container with desiccant packets.
Once you add bacteriostatic water to a lyophilised peptide, the clock starts ticking. The peptide is now dissolved in solution and subject to hydrolysis (water breaking peptide bonds), oxidation, and potential bacterial contamination.
Refrigerate immediately after reconstitution. Never freeze a reconstituted peptide unless you're prepared for the consequences:
Do not freeze reconstituted peptides. Freezing and thawing creates ice crystals that can physically damage peptide structures and cause aggregation. If you must store long-term, aliquot the solution into single-use portions before freezing - and never refreeze a thawed aliquot.
Reconstituted peptides are more light-sensitive than their lyophilised form because dissolved peptides are more reactive. Store vials in a dark area of the refrigerator, inside their original box if possible, or wrap them in aluminium foil.
The standard guidance is use within 30 days of reconstitution when stored at 2–8°C in bacteriostatic water. The benzyl alcohol in BAC water inhibits bacterial growth, but it doesn't stop chemical degradation.
Some peptides are more stable than others in solution:
| Stability | Examples | Reconstituted Shelf Life |
|---|---|---|
| High | BPC-157, TB-500, GHK-Cu | 28–35 days |
| Moderate | CJC-1295, Ipamorelin, Semaglutide | 21–30 days |
| Lower | HGH, IGF-1 LR3, MGF | 14–21 days |
If you notice any of the following, discard the vial:
Lyophilised: Freezer (−20°C), dark, dry, sealed → 24+ months
Reconstituted: Fridge (2–8°C), dark, BAC water, swab before each use → 30 days
Never: Leave reconstituted vials at room temp, freeze/thaw solutions, expose to direct light
All New-U Peptides arrive lyophilised and independently verified by Janoshik & Freedom Diagnostics. 10-vial packs, shipped worldwide.
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