Tosun NL, et al. - By performing a pilot double-blind, placebo-controlled randomized clinical trial, researchers compared the efficacy of progesterone (PRO) vs placebo (PBO) for smoking cessation in men and women. They randomly allocated (1:1 within sex group) 216 participants including 113 men (18–60 years; PRO=56, PBO=57) and 103 women (18–50 years, pre-menopausal with self-reported regular menstrual cycles; PRO=51, PBO=52) to either PRO (200 mg twice daily) or PBO. Findings suggest the possible efficacy of oral micronized progesterone in supporting smoking cessation in women. There was a significant difference in 7-day point prevalence abstinence at week 4 among women, but not men.