OBJECTIVE This prospective observational noninterventional study aimed at collecting information on changes in cycle control, dysmenorrhea, androgen-related skin conditions and tolerability in a large cohort of women who switched their oral contraceptive (OC) to 2.0 mg chlormadinone acetate (CMA)/0.03 mg ethinylestradiol (EE) (Belara). METHODS In a total of 20,897 women who were enrolled in a four-cycle clinical evaluation at 1597 gynecological practices throughout Germany, there are 16,781 women who switched from another contraceptive. RESULTS The most frequently mentioned complaint for switching contraceptive was seborrhea/acne (6933/16,781 women; 41.3%). This was followed by cycle irregularities (18.8%), headache (15.9%), breast tension (15.1%), amenorrhea (14.9%), spotting (12.8%) and dysmenorrhea (11.7%). After switching to CMA/EE treatment, these symptoms decreased substantially or even disappeared in a large number of women. The vast majority of study participants scored both tolerability and well-being on CMA/EE intake as 'very good' or 'good'. The results revealed that 13,508 women (80.5%) stated being more satisfied or even much more satisfied on CMA/EE intake compared to their previously used contraceptive; most of them had taken progestins of the nortestosterone type. CMA/EE produced beneficial effects on skin conditions and well-being in OC switchers who experienced dissatisfaction with their previous contraceptive regimen. CONCLUSIONS The results of this observational study support that 2.0 mg CMA/0.03 mg EE is well tolerated, provides a reliable cycle stability and is very effective in diminishing dysmenorrhea and other cycle-related complaints. Women suffering from problems on hormonal contraception received benefit from switching to the progesterone derivative CMA-containing OC.