Fact Check: Birth control pills are now classified as cancer-causing? No, claim is misleading

Hyderabad: Multiple posts on X claimed that birth control pills have recently been classified as cancer-causing agents by the World Health Organisation (WHO).

“Birth control pills are now listed as a Group 1 cancer-causing agent - WHO. And these are sold in India like peanuts,” said an X user.

“BREAKING Birth control pills (combined estrogen–progestogen oral contraceptives) are now classified as Group 1 carcinogens by the World Health Organisation’s International Agency for Research on Cancer (IARC),” said another X user.

Similar claims have been circulating widely on the X as well as Instagram (links here and here), suggesting this is a recent development that should alarm women using oral contraceptives.

Fact Check

NewsMeter found that the viral claims are misleading. The International Agency for Research on Cancer (IARC) has included combined oral contraceptives in Group 1 since 2005, not recently. Moreover, the classification reflects a complex cancer risk profile where these pills reduce some cancer risks while slightly increasing others.

Not a new classification

The IARC, the WHO’s cancer research agency, has included combined oral contraceptives (containing both oestrogen and progestogen) on its Group 1 list since 2005.

Only the combined pill is included in Group 1. The mini pill, which contains progestogen only, is categorised in Group 2B, meaning it is considered ‘possibly carcinogenic to humans.’

Group 1 includes substances where sufficient evidence of carcinogenicity has been demonstrated, such as alcohol, tobacco, asbestos, processed meats and sunlight radiation.

The complex cancer risk profile

“A woman swallows a small pill every day. That pill carries synthetic hormones, either a combination of oestrogen and progestogen, or progestogen alone. These hormones talk to the brain, specifically the pituitary gland, and tell it to stop releasing the signals that trigger ovulation. No egg releases, no pregnancy follows. That is the core mechanism,” said Dr Rekha Chitravan, gynaecologist and obstetrician based in Hyderabad.

The relationship between oral contraceptives and cancer is nuanced. Research shows these pills reduce certain cancer risks while slightly increasing others.

According to the National Cancer Institute, the United States government’s principal agency for cancer research, “Overall, women who had ever used oral contraceptives had a slight (7%) increase in the risk of breast cancer compared with women who had never used oral contraceptives. Women who were currently using oral contraceptives had a 24 per cent increase in risk that did not increase with the duration of use. Risk declined after use of oral contraceptives stopped, and no risk increase was evident by 10 years after use had stopped.”

For cervical cancer, the National Cancer Institute noted that women who used oral contraceptives for 5 or more years have a higher risk, with a 10 per cent increased risk for less than 5 years of use, 60 per cent with 5-9 years, and doubling with 10 or more years. However, risk declines after women stop using them.

The protective effects against other cancers are significant. “Women who have ever used oral contraceptives have a lower risk of endometrial cancer than women who have never used oral contraceptives. Risk is reduced by at least 30 per cent, with a greater risk reduction the longer oral contraceptives are used. The protective effect persists for many years after a woman stops using oral contraceptives,” the National Cancer Institute stated.

For ovarian cancer, “Women who have ever used oral contraceptives have a 30 to 50 per cent lower risk of ovarian cancer than women who have never used oral contraceptives. This protection has been found to increase with the length of time oral contraceptives are used and to continue for up to 30 years after a woman stops using oral contraceptives.”

Oral contraceptive use is also associated with 15 to 20 per cent lower risks of colorectal cancer, according to the National Cancer Institute.

Expert medical perspective

Dr Chitravan addressed the cancer concerns, “Patients ask me this every week. The honest answer has two parts. Research shows oral contraceptives reduce the risk of ovarian and endometrial cancer, and that protection persists for years after a woman stops taking them. But the same research shows a modest increase in risk for cervical cancer and a slight increase for breast cancer, particularly in current users. The risk is not zero, but it is not alarming either. A woman with a strong family history of breast cancer needs a conversation before she starts the pill, not after.”

WHO’s position

WHO emphasised that oral contraceptives remain safe for most women: “Most women can safely use oral contraceptives, including adolescents, women over 40, women living with HIV, and women regardless of whether they have had children.”

According to WHO: “Oral contraceptives are not only one of the most effective ways to prevent unintended and high-risk pregnancies, but also a major public health achievement recognised for improving women's health, reducing maternal deaths, and supporting education and economic opportunities.”

WHO’s statement noted: “Oral contraceptive pills show a complex association with cancer risk. They help protect against ovarian and endometrial cancers, reducing the chance of these cancers the longer they are used. At the same time, women who use oral contraceptive pills have a higher risk of cervical cancer compared to those who do not.”

Cancer Research UK noted: “Benefits often outweigh risks for many users; discuss with a doctor for personalised advice, especially given family history or other factors. Modern lower-dose pills may carry less risk than older formulations.”

The viral claims that birth control pills are ‘now’ classified as Group 1 carcinogens are misleading. The IARC has classified combined oral contraceptives in Group 1 since 2005, not recently.

The cancer risk profile is complex: while oral contraceptives slightly increase risks of breast and cervical cancers, they significantly reduce risks of ovarian, endometrial and colorectal cancers.

WHO confirms that most women can safely use oral contraceptives and considers them a major public health achievement. Women should discuss their individual risk factors with healthcare providers.

The claim is misleading.