A study was performed to evaluate the role of progestogens, on estrogen-induced changes in lipoprotein levels. Sixty postmenopausal symptomatic women, aged 36-59, were included in the study. They were prospectively randomized to a sequential schedule (n = 20), 17beta-estradiol transdermally 0.05 mg/day on days 1-24 and medroxyprogesterone acetate 10 mg/day orally on days 15-24 or a continuous schedule (n = 20), 17beta-estradiol transdermally 0.05 mg/day and medroxyprogesterone acetate 2.5 mg/day orally on days 1-24. Patients who had total abdominal hysterectomy + bilateral salphingooopherectomy (n = 20) received only 17beta-estradiol 0.05 mg/day continuously. Serum total cholesterol (TC), high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol and triglyceride (TG) levels were determined prior to and at the 3rd, 6th and 9th month of therapy in all groups. Mean TC, TG and LDL cholesterol levels did not change significantly during therapy (P > 0.05). Only the mean HDL cholesterol levels showed significant increases in all groups; from 42.30 +/- 9.97 mg/dl to 64.10 +/- 6.81 mg/dl in group I (P < 0.001), from 41.85 +/- 9.09 mg/dl to 60.65 +/- 7.41 mg/dl in group II (P < 0.001) and from 40.70 +/- 11.26 mg/dl to 58.80 +/- 7.74 mg/dl in group III (P < 0.001). It is concluded that medroxyprogesterone acetate, whether used continuously or sequentially, does not oppose the beneficial effects of transdermal 17beta-estradiol on the lipoprotein profile.