What’s Up With Emergency Contraception & Your Weight?

Have you been watching — and loving — Shrill, Hulu’s new comedy series adapted from Lindy West’s book, Shrill: Notes from a Loud Woman? We have!

One episode raised questions about the effectiveness of emergency contraception for folks above a certain weight or BMI. Does the morning-after pill have a weight limit?

We asked Evelyn Kieltyka, MFP’s vice president of program services, to break it down for us. Here’s what she told us:

Plan B Emergency Contraceptive

  • Effective if taken within 5 days of unprotected sex
  • Based on your BMI/Height to weight ratio.
  • Over the Counter, ID not required
  • No appointment necessary

ELLA Emergency Contraceptive

  • Effective if taken within 5 days of unprotected sex
  • Higher BMI
  • Available at clinics and most pharmacies
  • Prescription based.
  • Appointment Necessary

Evelyn further referred us to the Office of Population Research at Princeton University, which states:

In clinical trials of women using EC pills (progestin-only, such as Plan B One-Step or Next Choice, or ulipristal acetate, such as ella) obese women (with a body mass index, or BMI, of 30 or greater) became pregnant over 3 times more often than non-obese women. However, ulipristal acetate (ella) may be more effective for overweight or obese women than progestin-only EC (Plan B One-Step, Next Choice). EC appears to decline in efficacy as BMI increases; in fact, for women with a BMI of 26 or over who used progestin-only EC, pregnancy rates were no different than would be expected if they hadn’t used EC at all. Ulipristal acetate (ella) appeared to lose effectiveness at a higher BMI threshold of 35.1, 2 Some new evidence3 is emerging that may support doubling the dose of progestin-only EC for obese women, but it’s not certain whether it would be effective.

The most effective choice for emergency contraception for overweight or obese women is the copper IUD. The effectiveness of the copper IUD used as EC is greater than 99%, no matter how much you weigh (and it provides at least 10 years of excellent ongoing contraception).

MFP provides both Plan B and Ella at our 18 clinics statewide.