This study is a controlled, randomized and single-blind clinical trial that is performed on 44 patients with polycystic ovaries between 16 and 45 years old and Body Mass Index more than 25. Patients who are diabetic, hypothyroidism, nonclassic congenital adrenal hyperplasia or prolactinoma will be excluded. All of the patients should signed informed consent for taking either Bromocriptin or placebo; but, they will not be aware which group of study (experimental or control) have been entered. Patients participating in this research, randomly select a numbered card in sealed envelopes in order to enter the control or the experimental group. Giving the medication and randomization process are done by researcher, accordingly, this study is single-blind. At the beginning of the study, fasting blood sugar and fasting insulin are measured as a basis to the prescription of medication or placebo in both groups. Measurement of fasting blood sugar and fasting insulin are done through Glucose Oxidase and Chemiluminescence methods, respectively. Then the main group is given 2.5 milligram of Bromocriptin once daily for 8 days to be taken after meal.The control group is given placebo tablets similar to Bromocriptin once daily for 8 days. Placebo is similar to that of Bromocriptin tablets in terms of shape, colour and flavor. Its components include: micro-crystalline cellulose, lactose, starch, sorbitol and magnesium stearate. To control the correct use of medications, pills and placebos are given to patients and at the end of study, the empty blisters of pills are collected and controlled. If a patient has severe nausea and vomiting, she will be excluded from study. Upon completion of study period (8 days), fasting blood sugar and fasting insulin are measured again, in both groups, using the above mentioned methods. Finally the collected data will be analyzed.