Combined Oral Contraceptive Patient Information Fact Sheet

What is a combined oral contraceptive?
Combined oral contraceptive (COC), also known as the birth control pill or just “the pill” is a medication taken daily to prevent pregnancy. Some women take the pill for other reasons than preventing pregnancy. COCs contain two hormones, estrogen and progestin. These pills are taken every day and prevent pregnancy by keeping the ovaries from releasing eggs. The pill also works by causing the cervical mucus to thicken, which blocks sperm from meeting with and fertilizing an egg.

How do I use it?
Combined pills are typically packaged as 21 “active” pills that contain hormones. One pill is taken daily for 3 weeks, followed by 1 week off. Others are packaged as 28 pills that include 21 “active” pills taken daily, followed by 1 week of “inactive” reminder pills that don't contain hormones (Loestrin, Nortrel, Ortho Tri-Cyclen, Tri-Sprintec). With either the 21- or 28-day pills, protection against pregnancy continues during the week where no active pills are taken.

Some women use combined pills to limit the number of periods they have, or even to prevent them altogether. Extended cycle use involves taking 12 weeks of active pills followed by one week of inactive pills. Women on an extended cycle have 3 or 4 periods a year. The active ingredients in extended cycle contraceptives are levonorgestrel with ethinyl estradiol (Jolessa, Seasonique, Camrese). Continuous use of pills is where a woman takes an active pill daily so she will not have any periods.



What are the advantages?

  • Safe and effective in preventing pregnancy
  • Do not have to think about birth control when you want to have sex
  • Additional benefits such as fewer menstrual cramps, less acne, and stronger bones
  • May also reduce the risk of some cancers that affect reproductive organs
What are the disadvantages?
  • The pill does not protect against sexually transmitted infections (STIs)
  • You must take your pills every day
  • Certain antibiotics and supplements may make birth control pills less effective
  • If you stop the pill, it may take a month or two before normal periods return
  • Combined pills may cause dizziness, nausea, mood swings, and weight gain (these side effects often go away in a few weeks or months). Discuss your medical history with your health care provider before using any birth control pill, and let them know if you develop any side effects.
  • Rarely, use of the combined pill increases the risk of blood clots, heart attack, and stroke.

What if I miss or take the pill late?
If 1 pill is late <24 hours or missed 24 to <48 hours later than the usual time, take the pill as soon as possible once you remember. Continue taking the remaining pills at the usual time, even if it means taking 2 pills on the same day. No additional contraceptive protection is needed. Additionally, an emergency contraceptive is usually not needed but can be considered if hormonal pills were missed earlier in the cycle or in the last week of the previous cycle.

If ≥2 consecutive pills are missed ≥48 hours later than the usual time, it is recommended that you take the most recently missed pill as soon as possible while any other missed pills should be discarded. Continue taking the remaining pills at the usual time, even if it means taking 2 pills on the same day. It is advised that you use back-up contraception or avoid any sexual intercourse until you have taken your pills for 7 consecutive days. 



If this occurred during the first week and you had unprotected sexual intercourse within the past 5 days, emergency contraception should be considered. They may also be considered at other times as appropriate.

If this occurred during the last week (eg, days 15–21 for a 28-day pill pack), skip the hormone-free interval by finishing the pills in the current pack and starting a new pack the next day. However, if you are unable to start a new pack immediately, use back-up contraception or avoid sexual intercourse until you have taken the pills from a new pack for 7 consecutive days.

What if vomiting or diarrhea occurs?
If vomiting or diarrhea occurred for any reason within 24 hours or 24 to <48 hours after taking the pill, it is unnecessary to take another pill. Continue taking pills daily at the usual time. Emergency contraceptive is usually not needed but can be considered as appropriate. No additional contraceptive protection is needed.

If vomiting or diarrhea occurred ≥48 hours after taking the pill, continue taking the pills daily at the usual time. It is recommended that back-up contraception is used or avoid any sexual intercourse until pills have been taken for 7 consecutive days after vomiting or diarrhea has resolved.

Skip the hormone-free interval by finishing the pills in the current pack and starting a new pack the next day if vomiting or diarrhea occurred during the last week (eg, days 15–21 for a 28-day pill pack). If you are unable to start a new pack immediately, use back-up contraception or avoid sexual intercourse until pills from a new pack have been taken for 7 consecutive days.

Emergency contraception should be considered if vomiting or diarrhea occurred within the first week of a new pill pack and unprotected sexual intercourse occurred in the previous 5 days. It may also be considered at other times as appropriate.

Further Information:
Centers for Disease Control and Prevention: www.cdc.gov/mmwr/preview/mmwrhtml/rr62e0614a1.htm?s_cid=rr62e0614a1_x#Tab2
U.S. Department of Health & Human Services: www.hhs.gov/opa/reproductive-health/contraception/birth-control-pills/index.html

Created July 2013