Dr. Staci Tanouye is a board certified OBGYN who writes for In The Know, and she’s here to help debunk a recent and disturbing TikTok trend: users posting videos claiming certain supplements or foods somehow “cancel out” birth control pills, a.k.a oral contraceptive pills (OCP’s). By “cancel out,” they mean negatively interact with birth control pills, rendering them ineffective. Below, Dr. Tanouye breaks it all down for you.
So what actually interacts with birth control pills and what doesn’t?
This can be a really confusing question with potentially confusing answers. I’m sure at one point, your Aunt Karen told you she once lived next door to some health care provider who told her that the sun cancels out birth control pills, meaning you would definitely get pregnant by walking outside without sunscreen.
Well, probably not exactly like that, but you see where I’m going with this.
To be fair, the myth that certain things — from sunlight to antibiotics — can interact with birth control pills has been around for decades. Some of these myths are even still perpetuated by health care providers and pharmacists to this day. I can see how navigating the truths and the myths surrounding the “canceling out” of birth control pills can be very confusing.
But what I’m now starting to see online is people making dangerous, rampant claims that everything from alcohol to melatonin to cinnamon can inhibit the effectiveness of OCPs. Yes, I’m not even kidding, cinnamon. There are so many mixed messages (and crazy rumors) about what and how things could potentially interact with birth control pills.
Here are the important things to remember:
1. Failure rates of OCPs with average use can be up to 9% — regardless of other medications taken at the same time.
That’s not a small number when it comes to unplanned pregnancies, so it’s important to realize that while we often want to blame external forces, accidents and mistakes in taking OCPs happen far more often than you think. In addition, anything that affects the absorption of any medication could decrease its efficacy. So things like a stomach bug, various illnesses or bariatric surgery can impact the absorption of OCPs and increase failure rates.
2. Some medications can decrease concentrations of either ethinyl estradiol (synthetic estrogen) and/or the progestin component in OCPs.
This is due to certain medications unregulating liver enzyme activity which increases the metabolism of the OCP, causing a decrease the concentration of the OCP. Basically, these medications can make birth control less effective. But the list of medications that do this is much shorter than you think:
Phenobarbital and other barbiturates; anticonvulsants, such as phenytoin, carbamazepine, primidone, topiramate, felbamate, and oxcarbazepine; the antibiotics rifampin and rifabutin (yep, just the two — that’s all, folks); the antifungal griseofulvin; anti-HIV medication; and St. John’s Wort.
At one point, tetracyclines and penicillins were thought to decrease the efficacy of OCPs. But this finding (based on small studies) has since been disproven by larger studies as well as pharmacokinetic studies. But we know in science and medicine that nothing is impossible and sometimes data evolves. If you’re still worried, it’s always a good idea to add a condom — especially since condoms come recommended for preventing sexually transmitted infections anyway.
3. Even these medications don’t make the effectiveness of an OCP automatically zero.
But decreasing the concentration of an OCPs estrogen component may make them less effective at preventing ovulation. Therefore, the failure rate won’t be 100% every single you take these other meds along with OCPs. But it may be higher than the baseline failure rate of 9%. This also means that if a person is on one of these medications, OCPs could still be an option for them with appropriate informed consent, especially if they can’t take or don’t have access to other options. If possible, the addition of a barrier method, like a condom, is a good idea. Basically, in some patients, something may be better than nothing.
4. Interactions between medications and OCPs can also mean interactions other than decreasing OCP effectiveness.
For example, OCPs might decrease the effectiveness of lamotrigine, an anti-seizure medication. In addition, some medications can actually increase concentrations of OCPs or vice versa. Melatonin is one example. If taken with an OCP, the concentration of both the OCP and the melatonin could potentially increase. There’s limited data here, but it is possible. Grapefruit is another example that may increase concentration of the OCP. Increasing circulating concentrations of something could increase side effects but should not alter efficacy.
To sum things up:
- The only antibiotics ever shown to decrease the concentration of oral contraceptives and therefore decrease efficacy are rifampin and rifabutin.
- Remember, OCPs have a baseline typical use failure of up to 9% for multiple different reasons that don’t include antibiotic use. Misplaced blame is not helpful to solving the underlying issues here.
- OCPs may also affect concentrations of other medications both positively and negatively.
- Things that don’t “cancel out” birth control pills: melatonin, grapefruit, caffeine, nicotine, alcohol, cinnamon and most antibiotics.
Whenever in doubt, add another backup method, if possible.
You can follow Dr. Staci Tanouye on Instagram and TikTok for more.
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