Polycystic ovarian syndrome (PCOS) is the most frequent endocrine disorder affecting women of reproductive age, with a prevalence of 10 to 13%. PCOS is characterized by irregular menstrual cylcles/ovulatory dysfunction, hyperandrogenism, and polycystic ovarian morphology. For infertile patients seeking ovulation induction, letrozole is the drug of first choice. For PCOS patients not seeking pregnancy, there exists a variety of treatments to alleviate symptoms. It has been demonstrated that artemisinin derivatives can promote energy expenditures and insulin sensitivity by activating thermogenic adipocytes, thereby protecting against diet-induced obesity and metabolic disorders in rodents. Recently, we showed in a single arm pilot study including 19 PCOS-patients, that dihydroartemisinin ameliorated hyperandrogenemia reduced antral follicle count and normalized menstrual cycles. Based on these findings, we aim to evaluate the efficacy of dihydroartemisinin in women with PCOS in a placebo controlled randomized clinical trial. The primary outcome is return of regular menstrual cycles within 6 months after start of treatment, with antral follicle count and metabolic profile being secondary outcomes. The results will potentially impact the standard of care for patients diagnosed with PCOS.