Healthy young female volunteers were studied to investigate changes in high-density-lipoprotein (HDL)-cholesterol in women using a wide range of contraceptive steroids and related hormones. These volunteers received 21-day courses of oral treatment with either norethisterone acetate (1,2, or 5 mg) or ethinyl estradiol (20 or 50 mcg daily). Measurments of HDL-cholesterol (performed by differential precipitation with manganese chloride/heparin) in the study group were compared with measurements in groups of women receiving progestins or estrogens for gynecological indications, and in women taking oral contraceptives. Data presented tabularly show that unopposed estrogens stimulated increases in HDL-cholesterol, whereas progestin-only regimes showed suppression of the HDL-cholesterol concentration. Combined hormonal preparations yielded more equivocal results, depending on the relative doses and chemical compositions of the formulations. In general, combined formulations incorporating 50 mcg of ethinyl estradiol showed significant HDS-cholesterol suppression when administered with either norethisterone acetate, norethisterone, or lynestrenol (P .05). Because there is a general belief that HDS-cholesterol concentration is negatively correlated to cardiovascular disease risks, products inducing a large decrease in HDL-cholesterol should be avoided.