Glutathione On Arrival: What to Check and Do First

When a glutathione order arrives, check that each vial’s seal and cap are intact and that the contents look like a dry white cake or powder, then put the sealed vials in the fridge for near-term use or the freezer for longer holding. Dry glutathione has very little water for its thiol to react in, so it does not need an ice pack in transit. Everything changes once it is mixed.

Why glutathione travels without ice

A lyophilised vial contains the peptide as a freeze-dried cake with almost no water. The route that limits glutathione, oxidation of its thiol to GSSG, happens in solution, where oxygen and metal ions can reach it (Harbin and Stephens, US Patent 6,835,811, 2004). In the dry state it has very little to work with. Cayman Chemical lists its solid form with a stability of at least 4 years at minus 20 °C (item 10007461, product information).

The rest of the molecule adds little risk. It has no methionine, tryptophan, histidine or tyrosine to oxidise, and no asparagine, glutamine or aspartic acid to deamidate or isomerise. The patent figures that show a clear loss at room temperature were for solutions, not powder.

Every Vistara Labs order ships from within Canada by Canada Post Xpresspost, so the vials stay in the domestic network without a customs hold. A few days at ambient temperature in transit do not harm sealed glutathione, away from heat. An ice pack would add condensation risk inside the parcel without protecting anything.

What to check, vial by vial

The seal and cap

Each vial should have its crimped aluminium seal intact and the plastic flip-off cap in place over the rubber stopper. The cap protects the stopper surface from dust and handling. A cap that has popped off in transit does not by itself mean the vial is open; the crimp and stopper are the actual closure. If the crimp is loose or the stopper is visibly pushed in or pierced, contact us before using the vial.

The glass

Look for cracks or chips, especially around the neck. Intact glass and an intact crimp mean the vial is sealed.

The cake or powder

Lyophilised glutathione is white to off-white. At 600 mg or 1500 mg this is by far the largest fill in the catalogue, so expect a sizeable cake or a good depth of powder, not the small pellet of a 10 mg vial. It is normal for:

• the cake to have shrunk away from the glass or cracked into pieces;
• the cake to have broken up into loose powder that moves when the vial is tilted;
• powder to be scattered up the walls or on the underside of the stopper after travel.

None of these affect the peptide. Freeze-dried cakes are fragile and shift with handling. Tap the vial gently on the bench to settle the powder before reconstituting.

What would warrant a question is a cake that looks wet, syrupy or collapsed into a glassy film, or that has a yellow or brown tint. Those suggest moisture got in, and moisture is what lets the thiol start to react. A faint sulphurous smell on opening is normal for a cysteine compound.

What to do first

1. Leave the vials sealed. Do not open or reconstitute a vial until it is needed. The dry cake is the most stable form glutathione will ever be in.
2. Decide fridge or freezer. Vials for use in the coming weeks go in the fridge at 2 to 8 °C. Vials to be held for months go in the freezer at minus 20 °C. The full windows are on how long glutathione lasts.
3. Keep them boxed and dark. Store vials in their box in the main body of the fridge or freezer, not in the door.
4. Store the bacteriostatic water separately. Unopened bacteriostatic water keeps at room temperature; once its stopper has been pierced it is kept cool and used within its own window.
5. When you are ready to mix, let the vial warm to room temperature before piercing it so condensation does not form on the powder. The method is on the Glutathione handling page and the volumes on the Glutathione reconstitution page.

If the parcel sat somewhere warm

A parcel left in a mailbox or a warm vehicle for an afternoon is not a problem for sealed lyophilised glutathione, for the reasons above. Move the vials to cold storage when you get them and proceed as normal. A mixed vial is the opposite case: it should never be left warm, because the patent figures show that room temperature is when loss accelerates.

More on glutathione

How the peptide holds up over time is on the Glutathione stability page. Our certificates are on the lab reports page.