Morning-after pill could be ineffective for millions of American women, expert warns

Adriana Diaz
·3 min read
4
Dr. Chambers, Plan B and a couple in bed
Doctor Charis Chambers warned that levonorgestrel morning-after pills -- commonly sold as Plan B -- has been shown to have decreased efficacy based on both the weight and BMI (body mass index) of the user.

What a pill.

Traditional morning-after medication could actually be ineffective for millions of American women, an expert is warning.

Doctor Charis Chambers, who goes by The Period Doctor online, shared that people often ask at what weight the morning-after pill stops working.

Chambers revealed in a TikTok video that levonorgestrel morning-after pills — commonly sold as Plan B — has been shown to have decreased efficacy based on both the weight and BMI (body mass index) of the user.

Research has shown that people who are overweight — those with a BMI of 25 to 29.9 — were twice as likely to experience failure, the medical expert said.

Meanwhile, people who are obese — those with a BMI of 30 or greater — had four times the likelihood of failure, Dr. Chambers said.

Experts have warned that the medication is less likely to be effective for people who weigh 154 pounds or more and may not work at all for those who weigh more than 176 pounds.

Doctor Charis Chambers, who goes by The Period Doctor online, shared that people often ask at what weight the morning-after pill stops working. TikTok/@dr.charis
Doctor Charis Chambers, who goes by The Period Doctor online, shared that people often ask at what weight the morning-after pill stops working. TikTok/@dr.charis

That means that the emergency contraceptive would be less likely to be effective for 27.5% of American women and likely ineffective for 41.9% of American women, according to the U.S. Department of Health and Human Services.

Dr. Chambers advised that the most effective emergency contraception for those with a BMI over 30 or who tip the scale over 176 pounds is likely the copper IUD or the oral medication ulipristal acetate.

The Post has contacted Dr. Chambers for a comment.

The emergency contraceptive is less likely to be effective for 27.5% of American women and likely ineffective for 41.9% of American women, according to the U.S. Department of Health and Human Services. Getty Images
The emergency contraceptive is less likely to be effective for 27.5% of American women and likely ineffective for 41.9% of American women, according to the U.S. Department of Health and Human Services. Getty Images

Several other factors including when the medication is taken and what other medications the patient has already taken will impact the chances of successfully terminating a possible unwanted pregnancy.

The pill should be taken as soon as possible after having unprotected sex and have been found to be most effective within the first three days but may still work up to five days later, according to Planned Parenthood.

Several other factors including when the medication is taken and what other medications the patient has already taken will impact the chances of successfully terminating a possible unwanted pregnancy. Getty Images
Several other factors including when the medication is taken and what other medications the patient has already taken will impact the chances of successfully terminating a possible unwanted pregnancy. Getty Images

It should also not be combined with Rifampin (an antibiotic), Griseofulvin (an antifungal), certain HIV medicines, certain anti-seizure medicines and St. John’s Wort (an herb), Planned Parenthood warned.

Those who are concerned about taking the morning-after pill should contact a medical health professional.

Experts’ warnings of the possible uselessness of the emergency contraceptive come as Americans are reportedly having an alarming amount of unprotected sex and the country continues to debate the legality of certain reproductive health medications and procedures following the overturning of Roe v. Wade.