There are lots of reasons people take birth control. Maybe you take birth control to regulate an erratic menstrual cycle, clear up stubborn acne, or reduce pain and discomfort related to endometriosis.
Many people with ovaries, however, take birth control because it allows them to enjoy their sexual freedom with a lower risk of pregnancy. For the purposes of this article, the key phrase is “a lower risk.”
Although birth control is considered a highly reliable way to prevent pregnancy, its effectiveness largely depends on three things: the method you use, whether or not you use it correctly (i.e., on time), and if you use it consistently.
Today we’ll break down everything you need to know about some of today’s most common birth controls and what you can do to help maximize the efficacy of your choice.
Can you get pregnant on birth control?
In short: Yes, it’s possible to get pregnant while taking birth control. Accidents happen, as do moments of forgetfulness, and sometimes even highly effective methods of birth control can fail. How likely are you to get pregnant on birth control? It varies a lot depending on which type you’re using. Similar to most forms of protection in life (sunscreen, helmets, laws, parental advice), some contraceptives are more effective than others.
An IUD is a small, T-shaped device that’s placed inside your uterus to prevent pregnancy. There are two types of IUDs: hormonal and copper (non-hormonal). Both are more than 99% effective — meaning that less than one out of 100 people who use an IUD will get pregnant each year.
In fact, IUDs are so successful that they’re even comparable to female sterilization (both boast a cumulative pregnancy rate of <0.5% at five years). Plus, copper IUDs can even act as emergency contraception up to five days after unprotected sex.
Knowing all this, it’s no surprise that among women’s healthcare providers (aka, people who are super knowledgeable about birth control), IUDs are the method providers themselves most commonly use.
The pill is ubiquitous in the world of contraception, and for good reason. There are two types: “combination” pills that contain both estrogen and progestin and “non-combination” pills that contain progestin only. They’re 99% effective with “perfect use.” That said, actual use is closer to 91% effective, but the odds of preventing pregnancy are still pretty darn good.
Another reliable option is the birth control patch. Also known as the “transdermal contraceptive patch,” this small bandage-like adhesive transfers hormones through your skin right into your bloodstream. There are currently two prescription birth control patches sold in the United States: Xulane and Twirla.
The patch is considered to be a highly effective form of birth control… but again, this depends on how it’s used. Data from three large clinical trials tracking Xulane found that just 1 out of 100 patch-wearers became pregnant in one year. In reality, the typical success rate is closer to 91%-93% — meaning approximately 7-9 out of 100 patch users get pregnant each year.
Similar in size to a matchstick, the contraceptive implant is a small, plastic rod that’s placed under the skin of your upper arm. There’s currently only one birth control implant available in the U.S. and it’s called Nexplanon.
Although an extremely effective form of birth control — fewer than 1% of people who use it for one year will get pregnant — it’s actually one of the less commonly used methods. According to the Guttmacher Institute, just 0.5% of birth control users choose Nexplanon.
If shots make you feel weak in the knees, then Depo-Provera probably isn’t going to be the most effective or enjoyable birth control for you. As the name suggests, the birth control shot is an injection once every 3 months. It can be performed by a medical professional or self-administered at home. A study in the reproductive journal Contraception even found that people who self-administered the shot tended to use the birth control longer than those who received injections at a health center.
So is it worth the prick? According to Planned Parenthood, the birth control shot is more than 99% effective when used perfectly and hovers around 94% effective for typical use (so 6 out of every 100 shot users will get pregnant each year.)
What can impact the efficacy of birth control?
Efficacy is the ability to produce an intended result, so it essentially measures how well a contraceptive works to prevent pregnancy. As discussed earlier in this article, most birth controls are measured with two stats:
- The result when used perfectly
- The result with actual use
IUDs can last for 3-12 years and usually go unnoticed by sexual partners (when inserted properly). Without needing to remember to take a pill, change your birth control, or to rely on your partner to prevent pregnancy, it’s no wonder that people with ovaries have relied on IUDs as an effective form of birth control for nearly three decades.
The leading reason for failure is malpositioning (in the case of copper IUDs) or migration/ expulsion (when an IUD moves out of the uterus and the person is no longer protected from pregnancy). Thankfully, this is incredibly rare.
Your IUD is more likely to be expelled if:
- You've previously expelled an IUD
- You've never been pregnant
- Your periods are heavy and prolonged
- You have fibroids (benign tumor-like growths of the uterus)
- You have severe menstrual pain
- You're younger than age 25
- Your IUD was inserted immediately after childbirth
The most obvious threat to the success of the birth control pill is not remembering to take it on time ... or at all. The pill must be taken every day (and the minipill should be taken at the same time every day), so consider setting an alarm or keeping your pill pack next to your toothbrush to help you remember.
Some medication and supplements may impact how well the pill works, so touch base with your healthcare provider if you’re currently taking any of the following:
- Rifampin (an antibiotic)
- Griseofulvin (an antifungal)
- Certain HIV medicines
- Certain anti-seizure medicines
- St. John’s Wort
The birth control patch also thrives on consistency and routine. In order to optimize its effectiveness:
- Apply the patch to clean, dry skin once per week (every seven days) for three weeks, followed by a patch-free week.
- Avoid placing the patch anywhere it might rub against tight clothing (i.e., your breasts/chest and bra strap or your waistband and underwear).
- Although the patch begins to work as soon as you apply it to your skin, use a second form of contraception for the first seven days.
Nexplanon can cause irregular vaginal bleeding, according Dr. Eva Luo, an OB-GYN at Beth Israel Deaconess Medical Center in Boston, Massachusetts, which may prevent people from continuing the shot. "Generally, one-third [of users] maintain their regular bleeding patterns and are happy. One-third will have irregular bleeding, but it doesn't bother them and they are happy. The last one-third develop irregular bleeding and it drives them crazy and [they want] it out.”
Birth control shot
One benefit of the shot is if you get it during your period, it begins to work immediately — meaning there’s no need for backup birth control. However, this requires planning and if you’re not one to book appointments in advance or if you tend to be always on-the-go, you may want to find a birth control method with more flexibility.
The bottom line is that there’s always going to be some risk of pregnancy when you’re sexually active. While it’s true that you can indeed get pregnant while on birth control, hopefully this article provided some knowledge and comfort in understanding how to maximize the effectiveness of your birth control.
This article was medically reviewed by Dr. Jennifer Conti, MD, MS, MSc.