I did it for 4 days straight once and it was great. However, I was with the guy that actually made it. He had a Phd in chemistry and made me promise to never ever take it unless I was with him. I watched my friend drop into a mild coma right in the middle of the dance floor. Better things to do with my time. As far as great sex goes, there are better (and safer) things you and you gf can get for the and all weekender.