Let's examine the effectiveness of the different reversible contraceptive methods available ...


  • When a woman does not use contraception at all, she has an 85% chance of becoming pregnant within a year.
  • "Morning after pills" only delay ovulation. Therefore, it is ineffective if a woman has recently ovulated and the failure rates are as high as 25%.
  • If a woman uses a barrier method such as a condom, she has an 18% risk of pregnancy.
  • Hormonal contraceptives such as birth control pills, patches and vaginal rings have about a 9% failure rate, mostly because in the real world, it is often difficult for a woman to use these reliably. It does get better with the contraceptive shot, having a 6% failure rate, which usually occurs when a woman is unable to return to the clinic every three months for the injection.

The failure rates for long acting reversible contraceptives (LARCs) are exceptionally low (0.05-0.3%).

This means that they are over 99% effective!

The rates are so low that they rival permanent methods like tubal ligation and vasectomy. However, this choice leaves a woman’s options for future childbearing open. Nexplanon, the sub-dermal implant, is effective for 3 years and has a 0.05% failure rate. Levonorgestrel intrauterine devices (Mirena, Skyla, Kyleena, and Liletta) are effective for 3 to 5 years, and have a 0.2% failure rate. A great option for a woman who would rather not use hormones, the copper intrauterine device (Paragard) is effective for 10 years, and has a 0.3% failure rate.

In addition to being very reliable at preventing pregnancy, these devices have additional benefits. Most women experience far lighter and less painful menses while these devices are in place. Many women have no periods whatsoever. Additionally, for some women, estrogen containing contraceptives can pose risks to their health and none of these devices contain estrogen. See our FAQ page for more information.

It is important to know that LARC devices do not protect against sexually transmitted infections, including HIV/AIDS.