Bachelor Stars Are Promoting a Birth Control App on Instagram That Experts Say Uses One of the Least Effective Contraceptive Methods

In recent months, several former Bachelor cast members have used their Instagram accounts to promote the fertility awareness app Natural Cycles as a method of contraception. The celebrities touting the app to their millions of followers have sent up red flags to health experts, who warn that some fertility awareness methods may be less effective than other methods like IUDs.

Natural Cycles is a popular fertility-tracking app that relies on an algorithm that calculates the days of the month a woman is likely to be fertile based on basal body temperature readings and menstrual cycle data. It gives users a thermometer for daily temperature checks and claims to indicate when the user is ovulating and should either abstain from sex or use protection to prevent pregnancy. In 2018, it became the first app to be cleared for marketing as a contraceptive by the U.S. Food and Drug Administration (FDA) after being certified as a contraceptive in the European Union in 2017. While there’s nothing out of the ordinary about reality TV influencers advertising products on their social media accounts, these particular posts provide an incomplete—and therefore, potentially harmful—picture of how effective fertility awareness methods (FAMs) are at preventing pregnancy.

In the caption of a Jan. 25 Instagram post promoting Natural Cycles, former Bachelor and Bachelor in Paradise contestant Tia Booth wrote that she began using the app as an alternative contraception method to hormonal birth control.

“When I got off [birth control pills] I didn’t want to take any synthetic hormones so was tracking my cycle by counting days on my calendar through a period tracker, which ummm is not reliable,” the post reads. “Thankfully, my friend told me about [Natural Cycles], the first and only FDA cleared birth control app, and I’ve been using it ever since.”

At least six Bachelor Nation alums have posted ads for Natural Cycles over the past few months, promoting the app to over 4 million collective followers. However, obtaining accurate basal body temperature readings isn’t as simple as these Instagram posts make it seem, says Dr. Katherine Varda Schwab, an OB/GYN in Seattle. And an incorrect reading could potentially mislead users into thinking they’re not ovulating.

“Taking your basal body temperature should be done before you move out of bed in the morning. And depending on how well you wake up, getting that accurate reading is really difficult and usually takes months of practice, because you literally have to do it before you get up to pee or move your body,” Schwab says. “So you have to reach over and take your temperature and then have the wherewithal to record it as well. It’s difficult for most people to do.”

Schedule variations like sleeping during the day or waking up later or earlier than you normally do can also affect your basal body temperature, Dr. Jennifer Chin, a complex family planning fellow completing a rotation at the American College of Obstetricians and Gynecologists, says. “When you’re looking at fluctuations as small as 0.2 degrees, if you’re relying on that to tell you when you’re ovulating, some of these factors can definitely affect your temperature in that range.”

Natural Cycles claims to be 98% effective with perfect use and 93% effective with typical use. The company maintains its specific algorithm provides greater reliability than other calendar-based FAMs. In November 2019, The European Journal of Contraception & Reproductive Health Care published a study comparing the accuracy of predicting the fertile days in a woman’s menstrual cycle using different algorithms. The study found that the individualized algorithm of Natural Cycles shows a higher accuracy of predicting the fertile window compared to calendar-based FAMs like the Rhythm Method and Standard Days Method that rely solely on the date of menstruation.

But while FAMs like Natural Cycles can be a safe way to prevent pregnancy for some people, they’re not foolproof.

“To use FAMs effectively you need to be very knowledgeable about your menstrual cycle, when you’re ovulating, and when you’re fertile, so that you understand when it’s safer to have sex without risking pregnancy,” Planned Parenthood says. “It’s important to know that FAMs can be inconvenient and difficult to use correctly, so they’re less effective than other types of birth control, including IUDs, the implant, or permanent birth control — all more than 99 percent effective…”

FAMs generally have a relatively poor track record compared with other methods of contraception. The U.S. Centers for Disease Control and Prevention (CDC) reporting that up to 24% of women experience an unintended pregnancy within the first year of typical use and it broadly identifies FAMs as among the least effective family planning methods.

Natural Cycles seeks to differentiate itself from other FAMs with its algorithm and claim of higher effective rate with perfect or typical use. A 2017 study, co-authored by Natural Cycles CEO Elina Berglund, in the health journal Contraception, found 99% effectivity with perfect use and 93% with “typical” use. They say if their product is used correctly, it is comparable to other methods like the contraceptive ring.

“This is one little cog in the wheel in the range of things that people can use for contraception. And it feels good for a lot of people to be like, ‘Yes, I want to follow my natural cycle,’” Schwab says. “But without adequately talking about the risk of getting pregnant and being able to fully counsel somebody on what the comparative success rates [for other contraceptive methods are], I think [these influencers] are doing a disservice to the millions of people that they have influence over.”

FAMs are also usually low to no cost—although Natural Cycles costs $89.99 per year—have no side effects and can help you learn about your body and fertility.

“[FAMs] really allow the patient to become more aware of her own menstrual cycle and have a much greater awareness of her own body and her own fertility in a way that does not necessarily happen if she’s on some type of prescribed contraception,” adds Chin.

In a statement provided to TIME on Thursday, Natural Cycles co-founder and co-CEO Elina Berglund said that “there is no one size fits all when it comes to contraception.”

“At Natural Cycles we believe every woman—regardless of their age, medical history, or whether they are on a TV show or not—deserves to have as many birth control options to choose from as possible,” Berglund said. “While we have a variety of ads and some focus on how Natural Cycles is different from older, less effective fertility awareness methods, the goal of the ads mentioned in this article is to relay personal stories around how every woman’s birth control journey is different—and that there is an option for those looking for a natural, non-invasive method of birth control that has been cleared by the FDA.”

Bachelor contestants have used Instagram to advertise controversial products in the past. With Vulture reporting in 2015 that a reality TV star with 200,000-500,000 Instagram followers could make anywhere between $3,000-$7,000 for a single promotional post, social-media endorsement deals often go hand-in-hand with a run on one of the franchise’s shows.

“Overnight you have this huge following, so all these brands are like, ‘Here, do you want to work with us?’” Kaitlyn Bristowe, the lead on Season 11 of The Bachelorette, told The Cut in 2017. “So you get offers to do the Flat Tummy Tea and the teeth whitening and all that. For somebody who has worked a regular job before, you’re like, ‘Oh my gosh, you’re going to pay me to do that? Glorious.’”

As name-dropped by Bristowe, Flat Tummy Co. is one brand in particular that has come under fire in recent years for using Instagram influencers like the Bachelor stars and Kardashians to shill questionable diet products like detox teas, appetite suppressant lollipops and meal-replacement shakes.

But while these advertising tactics aren’t new, Natural Cycles might present a new set of issues. As Chin says, it takes a very specific patient to be a good candidate to use FAMs as contraception.

“You really need to be someone who has regular menstrual cycles that are predictable. And this requires a lot of homework and a lot of preparation,” she says. “Typically, for someone who’s considering a fertility awareness method, we recommend tracking your cycle for at least three cycles. To be a good candidate, you need to be someone who, for a consistent three months, are able to predict when you will ovulate and when you will have your menses in a very standard fashion.”

For people who have irregular periods, using FAMs as contraception can pose a high risk of unintended pregnancy, Chin says.

“If you’re someone who has irregular menses, or sometimes skips periods every other month, or has longer or shorter cycles, then this can make tracking your periods very difficult,” she says. “For people who don’t take the time to do the necessary three months or more of tracking, it can put you at very high risk for an unintended pregnancy, because you might be ovulating and not know and have intercourse during your fertile period.”

Fertility awareness apps also don’t factor in extenuating circumstances that might affect your cycle, and therefore the efficacy of the app as contraception, Chin adds.

“An app does not take into account travel that you might be doing, stress from working night shifts, stress from childcare, stress from being in a COVID-19 pandemic, stress from an argument that you had at work, and all of those things can significantly affect your cycle,” she says. “These aren’t things that would necessarily be tracked in a fertility awareness method application, and a particular stress could make the fertility awareness method unsuccessful.”