From various sources, I found that:
1 IU HCG = .1 mg HCG = 100 μg HCG
This means that:
1,000 IU/ml = 100 mg/ml = 100,000 μg/ml
And:
5,000 IU = 500 mg (not 1 mg)
The SIGMA Product Information sheet confuses more than it clarifies:
- "Dilute aqueous solutions undergo rapid loss of activity when stored frozen": There is nothing that defines how dilute is dilute or how rapid is rapid. 100,000 μg/ml might be considered dilute and 6 months might be considered rapid. Or perhaps rapid is 2 days.
- "Storage Temperature: -20°C": I have to believe this applies to the HCG which SIGMA supplies to pharmacies, which would mean the powdered form.
- "Solutions in water at ≥ 10 μg/ml can be stored as single use aliquots at 20°C": my dilution of 100 mg/ml is certainly ≥ 10 μg/ml, but I don't think I should store it at 20°C. Of course, I don't have it as single-use aliquots, but I am hard-pressed to understand how that would make a difference.
- "Solutions at 100 μg/ml in water are stable at 2-8°C for about 2-3 months": This statement only talks about solutions at 100 μg/ml, which leaves us wondering about solutions at 101 μg/ml or even 100,000 μg/ml.
From this, I get absolute no reassurance that reconstituted HCG can be frozen.
Using pregnancy strips to test for HCG is an option, but as I understand it, you can test for the presence of HCG, but not for whether potency has been reduced to 50% or 10% or whatever.
