Apparently, PMS doesn't just make you bitchy. It also makes you more likely to succeed at quitting smoking.
Researchers at the University of Minnesota have discovered that hormonal surges during the menstrual cycle affect both the severity of nicotine withdrawal symptoms and how fast nicotine leaves the bloodstream.
Two hundred women participated in the study, which asked half the participants to quit smoking in the first half of their cycle, before ovulation, while the rest were asked to quit after ovulation. Thirty days later, twice as many subjects in the second group were still not smoking.
Keep in mind, the success rate in the second group was only 40%. Which means, basically, that quitting smoking is hard no matter what time of month you try. But it can't hurt to have hormones on your side.