The treatment of PCOS involves clomiphene therapy used for early in the menstrual cycle. Drugs used in the treatment of polycystic ovarian syndrome include metformin , spironolactone, oral contraceptives and eflornithine. Oral contraceptives containing a combination of oestrogen and progestin increase sex hormone–binding globulin levels and thereby reduce the free testosterone level. Luteinizing hormone and follicle-stimulating hormone levels are also suppressed. However, the use of oral contraceptives may be associated with an increased risk of thrombosis and metabolic abnormalities.