How you prepare

By Mayo Clinic Staff

You'll need to request a prescription for combination birth control pills from your health care provider. Your health care provider will check your blood pressure and review your medical history, including asking about any medications you're taking.

Your health care provider will also ask about your concerns and preferences to help determine which type of combination birth control pill is right for you. Health care providers generally recommend pills with the lowest dose of hormones that will provide pregnancy protection while also maximizing important noncontraceptive benefits and minimizing side effects.

Although the amount of estrogen in combination pills varies from 20 to 50 micrograms (mcg) of ethinyl estradiol, most pills contain 35 mcg or less. Women who are sensitive to hormones may benefit from taking a pill with a lower dose of estrogen. However, low-dose pills may result in more breakthrough bleeding than may other pills.

Combination pills are categorized based on whether the dose of hormones stays the same or varies:

  • Monophasic. In this type of combination birth control pill, each active pill contains the same amount of estrogen and progestin.
  • Biphasic. In this type of combination birth control pill, active pills contain two different combinations of estrogen and progestin.
  • Triphasic. In this formulation, active pills contain three different combinations of estrogen and progestin. In some types, the progestin content steadily increases — while in others the progestin dose remains steady and the estrogen content increases.
Nov. 18, 2011