Oral Contraception Information

Oral contraceptives (OCs) are medicines taken to prevent pregnancy. OCs work by preventing the ovaries from releasing eggs. The hormones in OCs also cause the cervical mucus to thicken, preventing the sperm from entering the uterus. The hormones also cause the uterine lining to become thin, not allowing a fertilized egg to attach to the inside of the uterus. OCs are highly effective when taken exactly as prescribed. However, OCs do not prevent sexually transmitted diseases (STDs). Safe sex practices, such as using condoms along with the pill, can help prevent STDs.

Before taking the pill, you may have a physical exam and Pap test. Your caregiver may order blood tests that may be necessary. Your caregiver will make sure you are a good candidate for oral contraception. Discuss with your caregiver the possible side effects of the OC you may be prescribed. When starting an OC, it can take 2 to 3 months for the body to adjust to the changes in hormone levels in your body.


  • The combination pill. This pill contains estrogen and progestin (synthetic progesterone) hormones. The combination pill comes in either 21-day or 28-day packs. With 21-day packs, you do not take pills for 7 days after the last pill. With 28-day packs, the pill is taken every day. The last 7 pills are without hormones. Certain types of pills have more than 21 hormone-containing pills.

  • The minipill. This pill contains the progesterone hormone only. It is taken every day continuously. The minipill comes in packs of 91 pills. The first 84 pills contain the hormones, and the last 7 pills do not. The last 7 days are when you will have your menstrual period. You may experience irregular spotting.


  • Decreases premenstrual symptoms.

  • Treats menstrual period cramps.

  • Regulates the menstrual cycle.

  • Decreases a heavy menstrual flow.

  • Treats acne.

  • Treats abnormal uterine bleeding.

  • Treats chronic pelvic pain.

  • Treats polycystic ovarian syndrome.

  • Treats endometriosis.

  • Can be used as emergency contraception.


OCs can be less effective if:

  • You forget to take the pill at the same time every day.

  • You have a stomach or intestinal disease that lessens the absorption of the pill.

  • You take OCs with other medicines that make OCs less effective.

  • You take expired OCs.

  • You forget to restart the pill on day 7, when using the packs of 21 pills.