Combined Hormonal Contraceptive (CHC)

Combined Hormonal Contraceptives (CHC) are contraceptive methods that contain two synthetic hormones—estrogen and progesterone—which are similar to those normally produced by a woman.

What are your options for hormonal contraception?

Combined hormonal contraceptives include:

  • oral contraceptive pill ("The Pill")
  • transdermal patch (Evra)
  • vaginal ring (Nuva Ring)

CHC are very effective means of birth control. Research shows that out of 100 women using CHC correctly only one will become pregnant during a given year (99% effective). CHC is prescribed for many women in treatment of medical problems, such as painful, irregular or heavy periods, endometriosis, and ovarian cysts.

CHC help to prevent pregnancy, but will not prevent sexually transmitted diseases (STIs). Condoms may be used as a "back-up method" of birth control and may help to decrease the risk for transmission of STIs. How do combined hormonal contraceptives work to prevent pregnancy?

CHC prevent pregnancy by:

  • regulating hormone levels to inhibit ovulation
  • producing thick cervical secretions which act as a physical barrier to sperm
  • making the lining of the uterus less receptive to a fertilized egg

If you are sexually active, you may not be fully protected from pregnancy by CHC during the first seven days of use. Therefore, use a second method of birth control, such as foam and condoms, during the first seven days of your CHC method. Keep a second method of birth control (such as condoms) available at all times and learn to use it well. These measures are to avoid pregnancy. It is a good idea to always use a condom even when on a CHC method if you are at risk for sexually transmitted diseases.

Medications and CHC

The following medications and supplements may interfere with the effectiveness of CHC:

  • some antibiotics
  • anticonvulsants
  • oral antifungals: Diflucan
  • St. John's Wort
  • Provigil

We recommend that if you take the above medications and supplements and are sexually active with a male partner, you use a back-up method of birth control while using the medication and for 7 consecutive days once the medication is completed.

Other Medical Considerations

If a minor problem develops and you are considering stopping your CHC, call the Women’s Health nurse first. If you are unable to do this, use another method of birth control until you can get to the clinic. It is usually a good idea to complete the cycle unless the problem you are experiencing is serious.

When you are seeing a clinician for another problem, be sure and mention that you are using a combined hormonal contraceptive. This is particularly important if you have your leg in a cast, will be having surgery, or will be having medication prescribed. CHC may affect other medications.

If you decide you want to become pregnant, discontinue the use of the CHC at the end of a cycle. Use another method of contraception until you have had two or three normal menstrual periods. During this time, a multiple vitamin with folic acid is recommended to help prevent certain birth defects.

Smoking cigarettes while using CHC can increase a woman's risk for heart attack, stroke and formation of blood clots. If you currently smoke you should consider quitting. Talk with your clinician about resources available to help you quit.

Benefits of CHC

Some benefits of CHC (besides effective birth control) include:

  • improved menstrual regularity
  • reduced blood flow during menstruation
  • less iron-deficiency anemia
  • reduced risk of ovarian cancer and endometrial cancer (cancer of the lining of the uterus)
  • fewer functional ovarian cysts
  • fewer ectopic pregnancies (pregnancies outside the uterus, in fallopian tubes)
  • less fibrocystic breast disease (benign breast disease)
  • less dysmenorrhea (painful periods)
  • fewer fibroadenomas (benign fibrous-tissue tumors of the breasts)

Side Effects of CHC

Minor Side Effects

  • spotting (light bleeding) between periods (will usually stop after 1 to 2 months)
  • decreased menstrual flow, missed periods.
  • depression, mood changes, fatigue (return to clinic if severe)
  • decreased sex drive (rare)
  • acne (most women notice a decrease)
  • breast tenderness, fluid retention, weight gain
  • chloasma – skin darkens on upper lip, under eyes or on forehead; sun may make it worse and it may become permanent
  • more problems with yeast infections, vaginal discharge or itching

Serious Side Effects

  • hypertension (high blood pressure), often reversible once CHC are discontinued
  • gallbladder disease, with upper abdominal indigestion, gall stones

Possible Life-Threatening Side Effects

  • blood clots
  • heart attacks
  • strokes

If you experience any of these danger symptoms, see your clinician, return to the clinic, or go to the nearest emergency room immediately. Do not wait for these symptoms to get better.

  • severe abdominal pain or tenderness in the lower abdomen
  • chest pain, sharp, sudden shortness of breath or coughing up blood
  • headache, severe and sudden, or vomiting, dizziness or faintness
  • eyesight problems, such as sudden blurred or doubled vision or flashes of light
  • severe pain or swelling in calf or groin


Appointments can be made in person or by phone. If you are unable to keep your appointment, please call and cancel. Otherwise you will be charged for the visit.

To schedule or cancel appointments, call: 814-898-6217.

This content is reviewed periodically and is subject to change as new health information becomes available. This information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.