How to Compare Combination Birth Control Pills

In addition to their basic function of preventing pregnancy, combination birth control pills are used for different purposes, from acne control to period regulation. Different types of birth control pills also contain different levels of hormones.

Monophasic

• Monophasic are the most common type of combination birth control pills. They are also known as 21-day pills, because users take pills with active hormones for 21 days, and then placebos for 7 days during their menstrual cycles. These pills are called monophasic because they contain equal levels of estrogen and progestin.

Biphasic

• Like monophasic pills, biphasic combination birth control pills are designed to be used for 21 days with 7 days of placebo pills. Unlike monophasic pills, biphasic pills contain different levels of hormones.

Triphasic

• Triphasic pills, also designed for a 21-day cycle, contain three different levels of three separate hormones. The dosage levels of each of the three hormones change every seven days.