Today's low-dose combined OCs contain less than 50 g estrogen, down from 150 g in the first OC and 50 to 100 g in the OCs of the late 1960s and 1970s. Progestin doses also have dropped substantially. Also, side effects such as nausea, vomiting, cramps, breast discomfort, and headache occurred less often with less estrogen. Currently, doses of progestins in the norethindrone family norethindrone, norethindrone acetate, ethynodiol diacetate, and lynestrenol range from 0.4 to 2 mg. Pills containing the more potent progestins levonorgestrel, desogestrel, and gestodene use doses of 0.05 to 0.15 mg.
Research suggests that lower doses do lower risks for some conditions.