Molecularly targeted agents which inhibit the mammalian target of rapamycin (mTOR) pathway and/or circumvent p53 in the induction of apoptosis are exciting potential targets in ovarian cancer. Metformin is a biguanide, widely used in the treatment of type 2 diabetes mellitus, that has shown anti-cancer activity in preclinical studies. The main mechanism of metformin's effect is mTOR pathway inhibition and, in addition, it has been shown to circumvent p53-induced apoptosis making it an exciting, potentially effective drug in ovarian cancer.