I did the same and felt heavy also, esspecially in the legs. I had a terrible time getting to sleep though, so I had a bad experience and dont plan on doing them again. I wouldn't suggest doing them very often at all, ive heard once a month is very risky and even two times a year is the okay average. That maybe false, but its just what i've read and heard.

My Suggestion for you: Take 4 and take 2-3 shots. I've heard that will do many more wonders for you than just taking pills. DO NOT take 12 and drink.