The INSIDER Summary:
• With perfect use, the pill is more than 99% effective at preventing pregnancy.
• But certain things make it less effective, like skipping pills and having digestive issues.
• Certain medications can also mess with the pill — read on for specifics.
The great news about the pill is that it’s easy to use and it’s really effective at preventing pregnancy — if you use it exactly as directed.
With perfect use, the pill is 99% effective. But with typical use (and who among us is perfect?) the efficacy rate drops down to 91%, according to Planned Parenthood.
INSIDER asked two gynecologists about all the everyday things that can hamper the effectiveness of the pill. Here are the three things that can hamper the efficacy of your birth control:
1. Not taking pills at the same time every day.
First things first: You need to be vigilant about taking your pill every day, because missing doses makes it less effective. (Here’s what to do if you miss a pill.)
If you’re on the progestin-only pill (sometimes called the mini pill), you need to be extra vigilant and make sure you take it at the same time every day. If you take it any more than 3 hours late, you’ll need to use a backup method of contraception, according to Dr. Susan E. Pesci, MD, clinical instructor, OB/GYN, and Family Planning Specialist at Montefiore Health System.
If you take a combination pill (the kind with both progestin and estrogen), Pesci said there’s a little more wiggle room. But no matter which type you’re on, it’s good to get in the habit of taking it at the same time.
“It helps to get you in a pattern,” Pesci told INSIDER. “If you’re not in a pattern, you’re not going to remember to take it.”
2. Digestive issues.
Because pills are taken by mouth, they need time to move through the digestive system and get metabolized — or broken down — by the liver. If you vomit or have diarrhoea soon after swallowing your pill, you may not be protected.
“You want to give [the pill] 4 to 6 hours to ensure that it’s metabolized,” Dr. Salena Zanotti, MD, an OB/GYN at Cleveland Clinic, told INSIDER. “So if you throw up in the first few hours after taking the pill, just count that as a missed pill.”
“Any time you have a digestive issues where you’ve having malabsorption problems — say you’re travelling and you get traveller’s diarrhoea — they’re not really absorbing well,” Pesci said. “That can decrease efficacy as well.”
If you’re ever in doubt: Use backup contraception like a condom.
3. Other medications.
You’ve probably heard that antibiotics make the pill less effective — but this is a major generalization.
“That’s one of those myths that was started decades ago,” Zanotti said. “There’s really no evidence to prove that.”
The truth is that there are only two antibiotics hurt the pill’s effectiveness: rifampin and rifabutin. They’re prescribed very rarely (usually to treat tuberculosis, according to Bedsider). More common antibiotics like the kind you take for acne, UTIs, and strep throat won’t cause issues with the pill, both Pesci and Zanotti confirmed.
But there are few more medications to watch out for: Talk to your doctor if you take any medications for bipolar disorder or epilepsy (including Carbamazepine, Phenytoin, Phenobarbital, and more
), which can make the pill less effective. Also mention if you’re taking any drugs for HIV, because certain antiretroviral drugs including Nevirapine, Nelfinavir, and Darunavir can pose problems. The anti-fungal drug griseofulvin can also reduce the pill’s effectiveness.
Finally, steer clear of the herbal supplement St. John’s Wort. “There is some evidence that it could reduce the efficacy [of the pill],” Zanotti said. “You want to be cautious.”
The bottom line: Make sure your doctor knows about all the medications and supplements you’re taking — even over-the-counter ones that seem innocuous.
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