All i remember about it is that there was a guy who use to take some kind of drug that made him really horny and if i recall it he had black hair and there was apart that he seen a girl and started to thrust his hips and said"Gotta Gotta Gotta" and grab the girl and started to makeout with her(i think) If anyone knows what movie this is,please let me know.
I'm not positive, but it sounds like you might be thinking of Jekyll & Hyde... Together Again (http://imdb.com/title/tt0084171/combined). The main character is a doctor who invents a drug that basically turns him into a sex-crazed animal. When he takes it, he goes from a nerdy guy to one sporting a wild hairdo and gold chains.