I know what HCG is in the pregnancy dept. but didn't realise this was a diet aid - I thought it stood for something else.
Each time I had HCG surging through my body I packed a load of weight on, certainly didn'y lose any! :D
I'm not sure what that is but if any of my kids drank anything they were not supposed to I wold definately be on to A&E/ER or equivalent as barb said.
Hope he is okay.
If you haven't done so, by now, you need to call your local poison control center; they are the ones to answer a question like that.