When I was in college we would get HCG that came all in one bottle. It was sort of an hourglass shaped plastic jug, with a rubber stopper in the thin part of the “hourglass” part, which separated the powder from the liquid.
To reconstitute, you pushed down on the top, which broke the rubber stopper free allowing the water to mix in with the powder.
For the life of me, I can’t remember what brand it was, but it was very convenient.
Does anybody remember this type of HCG? I’ve never seen it since.