The Advertising Standards Authority (ASA) has banned a “misleading” Facebook advertisement for Natural Cycles, a Swedish contraceptive app, that claimed equal efficacy to more established methods of contraception.
The app requires women to take their basal body temperature on a daily basis, immediately upon waking, using a two-decimal basal cell thermometer. These sensitive thermometers can detect the minor rise in temperature that occurs around the time of ovulation. The daily readings are put into the app, which will then flag up days when the user is most fertile and advise them to either abstain from intercourse or use protection.
In the advertisement, which was seen on 20 July 2017, the app was described as a “highly accurate contraceptive app” and “clinically tested alternative to birth control methods”. In response to the ASA’s investigation, Natural Cycles said this assertion was based on clinical studies published in peer-reviewed journals.
The company claimed that the app had a “perfect use” failure rate of 1.0, meaning that of every 100 women using the app perfectly for one year, one of them would become pregnant. The “typical use” failure rate was estimated at 6.8 — on par with other birth control methods, such as condoms.
The ASA reviewed three published studies of the app — one of which was an observational study of more than 22,000 users. These studies showed that while perfect-use failure rates were comparable to other methods of contraception, the rate of perfect use was very low: only 9.7% of user cycles were considered to represent perfect use. The ASA therefore decided that it was misleading to use perfect-use data to claim the app as “highly accurate” — it said the relevant data was the significantly lower level of effectiveness seen in typical use.
Natural Cycles’ claim that the app is a “clinically tested alternative to birth control methods” was in itself unlikely to mislead users, the ASA ruled. But in the context of the advertisement, which described Natural Cycles as a “highly accurate contraceptive app”, it created a misleading impression: the evidence does not, the ASA said, support the claim that the app is highly accurate in typical use, and the studies found that it is “significantly less effective than the most reliable birth control methods”.
The ruling said: “We concluded that the claims ‘highly accurate contraceptive app’ and ‘clinically tested alternative to birth control methods’ were misleading.
“The ad must not appear again in the form complained about. We told Natural Cycles Nordic AB Sweden not to state or imply that the app was a highly accurate method of contraception and to take care not to exaggerate the efficacy of the app in preventing pregnancies.”
In a statement given to the BBC, Natural Cycles said it removed the advert as soon as it was notified of the complaint.
In the EU, Natural Cycles is a certified and CE-marked medical device of class IIb, intended to be used for contraception. This places it in the same risk category as a condom. At the beginning of August 2018, Natural Cycles was granted marketing approval by the US Food and Drug Administration.