HCG On Arrival: What to Check and Do First

When an HCG 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. Lyophilised HCG is a dry, stable material, so it does not need an ice pack in transit, but the powder is hygroscopic, so it does need to stay sealed and dry.

Why HCG travels without ice

A lyophilised vial contains the hormone as a freeze-dried cake with almost no water. The changes that limit HCG in solution, its two subunits separating and the protein unfolding, need a mobile, hydrated molecule to proceed; in the dry state they have very little to work with. Measured dissociation in solution was undetectable at 3 °C and measurable at 20 °C over three days (Sancken and Bahner, Prenatal Diagnosis, 1995), but that describes a liquid, not a cake.

The dry-state evidence is direct. The WHO 5th International Standard for chorionic gonadotrophin showed no significant loss of immunoreactivity or bioactivity at any elevated temperature in accelerated degradation testing, and NIBSC notes that because of the inherent stability of lyophilised material it may ship the standard at ambient temperature (NIBSC 07/364, 2013). ProSpec rates its lyophilised hCG as stable at room temperature for 3 weeks, with long-term storage desiccated below minus 18 °C (ProSpec, HOR-250).

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 room temperature in transit does not harm sealed HCG powder. An ice pack would add condensation risk inside the parcel without protecting anything, and for a hygroscopic powder condensation is the thing to avoid.

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. An intact closure is what keeps moisture out of the cake.

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 hCG is a white powder (NIBSC 07/364, 2013). HCG is labelled by activity, not weight, so the amount of material in a 5000 IU vial depends on the fill and on anything freeze-dried with it. Expect a cake or pellet at the bottom of the vial, which may be small. 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 hormone. 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, which matters for a powder that draws water from the air. Any tint is worth asking about.

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 HCG 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 storage temperature for the WHO standard. The full windows are on how long HCG 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 HCG handling page and the volumes on the HCG 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 HCG, for the reasons above. Move the vials to cold storage when you get them and proceed as normal. A mixed vial is different, because it is already in solution and its subunits separate with warmth; a mixed vial should be refrigerated promptly. HCG is supplied as a lyophilised vial only, with no ready-mixed spray.

More on HCG

How the hormone holds up over time is on the HCG stability page, and what it dissolves in is on the HCG solubility guide.