Can I drink on HCG?

Yes.

Be careful of 2 things though - what you mix your alcohol with, and the foods you're likely to be around if you're drinking.  I do not recommend beer - too many carbs. Bailey's Irish Cream or similar drinks are probably not a good idea. Spirits on the rocks or mixed with diet soda are probably ok.  A glass of wine with dinner is ok.  But not at every meal or every day - alcohol has calories.

Drink plenty of water if you're doing alcohol. 

HCG does tend to increase your sensitivity to alcohol, so be careful.

Also, since alcohol lowers your inhibitions, be very careful about any foods that you may be around.  Drinks are often served with fattening, off-protocol foods. 

If you like to drink, you can enjoy an occasional drink on the diet.  Just do it with caution.