Birth Control and Obesity

Medically reviewed by Sophia Yen, MD, MPH – Written by Pandia Health Editorial Team

According to an article by Jennifer A Robinson, MD and Anne E Burke, MD, hormonal birth control such as the patch or the pill is less effective for people that are overweight or obese  (with a BMI (body mass index) greater than 25). Although the pill and patch are still effective with a BMI greater than 30, it is more effective in people that are “normal” weight” (BMI of 18-25). This is because people that weigh differently from the “standard patient” process and store medication differently.

The same article suggests that long acting reversible contraceptives (LARCs) such as the IUD, implant, and depo shot maintain the same high efficacy regardless of weight.

The same is also true for emergency contraception (EC) or “the morning after pill.” Those with uteri that have a BMI greater than 25 have a 4 times higher risk of pregnancy after taking emergency contraception compared to women of “normal weight.” Plan B, a popular emergency contraception, is not effective for overweight or obese women aka with a BMI>25. The research has shown that taking Plan B and its generics for a woman with a BMI of 26 or greater is the same as taking a sugar pill or drinking water = does nothing. In contrast, ella (the emergency contraception that Pandia Health doctors prescribe and that you can ask your provider to prescribe) is more effective than Plan B for those with a BMI or 26 or greater.

If your BMI is 35 or greater, then it is best to use the copper IUD as your emergency contraceptive because Ella and Plan B won’t be effective.

All birth control patche are not recommended for those with a BMI greater or equal to 30, including Twirla (patch birth control with ethinyl estradiol and levonorgestrel) and Xulane/Zafemy (with norelgestromin) because of the increased risk of pregnancy = 8.64/100 women that use it for 1 year  and the risk for blood clots (VTE=Venous Thromboticembolic Events). For reference, the risk of pregnancy with many birth control pills is 7/100.

Just because a person is categorized as obese or overweight does not mean that the pill cannot benefit them. The pill can still be used to lessen acne, regulate their menstrual cycle, and reduce the chance of getting pregnant (although it may have a lower efficacy but still better than the condom, withdrawal, fertility awareness methods).

Check out www.pandiahealth.com if you are looking for an online prescription for ella or to #SkipTheTrip to the pharmacy each month or to get started on birth control!

The above information is for general informational purposes only and are NOT a substitute for professional medical advice. Always seek the advice of your doctor/primary care provider before starting or changing treatment.

updated 1.13.21