Background <p>Polycystic ovary syndrome (PCOS) is a pathologic entity demonstrating heterogeneous clinical manifestations such as symptoms and signs of excessive androgen production (alopecia, acne, hirsutism and/or hyperandrogenemia) as well as oligomenorrhea (oligo- or an- ovulation) eventually accompanied by polycystic ovarian morphology. Metformin (an activator of adenosine monophosphate-activated protein kinase belonging to the biguanide class), used as treatment for type 2 diabetes mellitus, reduces glucose production of hepatic origin and increases its utilization, via insulin action, in liver and muscle. In PCOS patients, the use of metformin decreases hyperinsulinemia, improves menstrual cyclicity, promotes ovulation, facilitates implantation, increases pregnancy rates, and lowers modestly androgen concentrations. Pharmaceutical molecules with anti-androgenic properties block the androgen receptor and/or inhibit 5α-reductase activity. The latter catalyzes the testosterone to dihydrotestosterone transformation. These molecules are used as second-line treatment for skin disorders which accompany PCOS. They can also be used in combination with or as part of combined oral contraceptives (COCs) to reduce stigmata of hyperandrogenism.</p> Methods <p>The combined use of metformin and pharmaceutical molecules with anti-androgenic properties targets two different aspects of PCOS pathophysiology i.e. insulin resistance with the former and hyperandrogenism with the latter. Metformin and pharmaceutical molecules with anti-androgenic properties mitigate hyperinsulinemia and hyperandrogenism-related symptoms of PCOS. This paper investigates the role of the combined administration of metformin and pharmaceutical molecules with anti-androgenic properties in the therapy of PCOS in adult women by reviewing critically studies employing combination of these therapeutic modalities.</p> Results <p>A combination of metformin-pharmaceutical molecules with antiandrogenic properties appears appropriate: 1. when a COC is not well tolerated, or it does not show clinical efficacy after a period of at least six months; 2. in PCOS women with obesity where the use of estrogen-containing COCs presents increased thromboembolic risk and insulin resistance should be tackled.</p> Conclusion <p>It appears that the combined administration of metformin and pharmaceutical molecules with anti-androgenic properties could be useful as treatment of PCOS patients, particularly in groups of patients not indicated for the use of COCs or with increased obesity as well as hyperandrogenic stigmata.</p>