Women stand a better chance of successfully quitting smoking if they stop during the later phase of their monthly menstrual cycle, according to new research conducted at the University of Minnesota and published in the May 2008 edition of the journal Addiction.

Sharon Allen and co-workers discovered that women who quit smoking right before they start to ovulate--the so-called follicular stage--relapsed more often than women who quit during the "luteal" stage, defined as the two weeks between ovulation and the start of a new cycle. In the study, 86 percent of women who gave up smoking during the follicular phase relapsed during the first 30 days, compared to 66 per cent of women who quit during the later luteal phase.

"Our findings support an important role for ovarian hormones in nicotine addiction and smoking cessation," the authors wrote.

The ebb and flow of estrogen and progesterone during the menstrual cycle can have a direct effect on mood, as evidenced by the well-documented premenstrual syndrome, or PMS. In addition to mood factors, the researchers suggested that female hormones might play a role in the speed with which nicotine is metabolized.

The study of 200 female smokers was conducted by the Tobacco Use Research Center at the University of Minnesota. Earlier work by the group, published in Nicotine & Tobacco Research, had established a strong suspicion that "withdrawal symptomatology in short-term smoking cessation in women is increased in the late luteal phase when pre-menstrual symptomatology is the highest." The group concluded that "it seems prudent to recommend that women quit during the follicular phase of their cycle."

In short, the work suggests that female smokers would be well advised not to inaugurate a quit attempt in the ten days preceding ovulation.