Oral contraceptives have differing mechanisms for controlling acne. Some of them include:
Micronor® (norethindrone 0.35 mg) They are used to treat women with elevated blood pressure, migraines, or those with a high heart diseases risk. They may have a higher that usual failure rate for normal use.
Most oral contraceptives combine estrogens (ethinyl estradiol) and Progestins. They are divided into Monophasic, Biphasic, and Triphasic pills. Monophasic pills have consistent amount of hormones, and reduce the chance of side-effects which occur due to changes in hormone levels. Biphasic pills deliver consistent amounts from day to day, but increase dosage in the middle of the month. Triphasic combination pills contain three varying doses of hormones, changing approximately every week.