In an unsurprising move, the FDA announced Thursday that it has officially approved the Opill, a progestin-only birth control pill, for over-the-counter use (OTC) for all women of reproductive age. It will be the first hormonal birth control pill ever to be sold without a doctor’s prescription in the United States, and may soon open the door for easier access to additional hormonal contraceptive methods, including combined formulations that also contain estrogen. The pill’s manufacturer, Dublin-based pharmaceutical company Perrigo, expects to have the product on the shelves in early 2024.

When the FDA’s Advisory Committee unanimously voted to approve Opill for over-the-counter use by all women of reproductive age this past May, they cited (among other purported benefits) the ease of access for women of color. Others noted that if made available without a prescription, Opill would likely attract a younger set, particularly teens and college-aged women, again because of ease of access. Meanwhile, women of color, specifically Black women and teens, are most susceptible to one of the deadliest risks of taking this drug: breast cancer.

For decades, women have been led to believe that progestin-only birth control pills have fewer risks and side effects than alternative formulations that also contain estrogen. While it’s true that progestin-only formulations (often referred to as “the mini Pill”) do not carry the same blood clot, heart attack, and stroke-related risks as combined pills, many of the other side effects remain the same, including mental health and breast cancer risks.

In the interim between when the Advisory Committee was supposed to vote on Opill’s OTC approval (November 2022) and when the vote actually occurred (May 10, 2023), a large-scale study from Oxford University was published, which confirmed that breast cancer rates are similar among women who take progestin-only birth control pills and those who take combined pills. Troublingly, this study also confirmed that, while these risks are lowered by discontinuing use of these drugs, they still remain higher for breast cancer than for those who have never used them. In other words, some amount of breast cancer risk is permanently elevated once a woman begins using any form of hormonal birth control.

Breast cancer is now the most-diagnosed cancer in the world; after lung cancer, it is responsible for the most cancer deaths in U.S. women. As reported in The Wall Street Journal in early May, the U.S. Preventive Services Task Force now recommends that women begin receiving regular mammograms at age 40—a decade earlier than the previous recommendation—precisely because incidence of breast cancer has been steadily rising in ever-younger women. Notably, the prognosis is worse for Black women, who, for poorly understood reasons, die of breast cancer at a 40 percent higher rate than white women.

While the exact reasons why birth control use is linked with increased breast cancer risk are unclear, one compelling theory concerns what we know of breast tissue development, and how the synthetic hormones found in hormonal birth control may overstimulate immature breast cells, leading to the formation of cancer in immature breasts. While the generally accepted statistic is that hormonal birth control use raises the average woman’s risk for breast cancer about 20 percent over never-users, looking at what stage of their breast development process women begin taking birth control pills may give us a better picture of individual risk.

Most breast cancers develop in Type 1 and Type 2 (immature) breast tissue lobules, while cancer almost never occurs in mature Type 3 or Type 4 lobules. Mature breasts seem to be able to handle hormonal stimulation (such as would occur with hormonal birth control use) without developing cancer, yet women do not have breasts made up of mature Type 3 of 4 lobules until they have carried a pregnancy to full term. This is perhaps why a 2007 meta-analysis showed that the relative risk of developing breast cancer is as high as 44 percent for women who began using birth control pills before their first full-term pregnancy, and as high as 52 percent for women who used the drug at least four years before their first full-term pregnancy (numbers far higher than the 20 percent average relative risk often cited for hormonal birth control use).

Further underscoring the significance of age at first use of hormonal birth control, a 2010 meta-analysis showed that women who began birth control before age 20 (when very few women have carried a full-term pregnancy) had nearly double the relative risk of developing breast cancer by a young age (30) than did their peers who began using birth control after age 20. (Outside the focus of this article, but no less pressing, is the fact that the risk of depression with birth control use also highly correlates with age of the user, with teens being at the highest risk, and progestin-only pills eliciting slightly worse mental health outcomes than combined pills.)

All of this makes it especially troubling that the suspected (or perhaps targeted) users for Opill are teens and college-age women (who have likely not yet carried a full-term pregnancy) and Black women, for whom breast cancer is disproportionately deadly. Given the increasing rates of breast cancer in the United States and around the world, the blind eye turned by our public health experts to birth control and its known links to the development of breast cancer seems ignorantly counterproductive at best, and disturbingly negligent at worst.