Morning-After Pill: Your Weight Plays a Role

Heavier women must plan ahead for reliable contraception

Heavier women who take the morning-after pill up to 72 hours after unprotected sex to reduce their chance of pregnancy may need to consider other emergency birth control options, such as an IUD.

Advertising Policy

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

The European manufacturer of the drug NorLevo® — chemically identical to what’s sold in the U.S. as Plan B — said that its drug is less effective or not effective at all in women who weigh more than 165 pounds.

The company found that NorLevo begins to lose effectiveness for women who weigh 165 pounds and is completely ineffective at 176 pounds. The company is changing the labeling for products sold in Europe. There have been no changes to the packaging for American products so far.

This can be unsettling news for American women who struggle with their weight. More than 60 percent of women in this country are overweight, and about one-third of those are obese.

What this means for women

If you find yourself in a situation in which you need emergency contraception, it’s still better to take it than not to take it. No matter what your weight, more pregnancies are prevented by using a morning-after pill than by doing nothing.

If you weigh more than 176 pounds, do not attempt to take more pills than the box recommends, thinking that it will make it more effective. No studies have evaluated the safety or efficacy of this idea.

Advertising Policy

I recommend that you focus on being more prepared in advance with a reliable form of contraception and don’t rely on a morning-after pill. This is especially true if you weigh more than 165 pounds.

An effective alternative

The most effective method of emergency contraception is to get a copper IUD implanted shortly after intercourse, which is also a very reliable form of contraception for the future.

Call your OB/GYN to have this procedure done as quickly as possible after having unprotected sex. Tell the scheduler that you need the appointment the same day. She may need to get a doctor’s approval to schedule the appointment, but the quicker you receive the IUD, the more effective it will be in preventing pregnancy.

My best advice, though, is to focus on being prepared ahead.

More about morning-after pills

These pills deliver hormones that confuse the body so that ovulation and transportation of the egg is interrupted. Sometimes they can cause your period to come early.

Advertising Policy

It’s also important to know that if the pills fail and conception occurs, there is no higher risk of miscarriage or birth defects in babies.

You don’t need a prescription to purchase emergency contraception, but you’ll have to ask for it if your pharmacist keeps it behind the counter. If it’s not behind the counter, look for it in the aisle near condoms and pregnancy tests.

More information

avatar

Elisa Ross, MD

Elisa Ross, MD, is a obstetrician and gynecologist in Cleveland Clinic’s Women’s Health Institute. She loves caring for and educating women.
Advertising Policy