15/07/2025

Yes, hormonal birth Control is a Carcinogen, But…

You might have heard somewhere through the grapevine that hormonal birth control was now officially classified as a class one carcinogen by the WHO. This would mean that birth control is as carcinogenic as radium, hepatitis, and tobacco.

Now, you might be tempted to throw your pills out of the window: and don’t let us stop you! Do what is best for you. However, you can throw them after we’ve shared with you all the information that you need to make an informed decision. Your choices shouldn’t be driven by fear but by knowledge.

This article will cover:

what is a group 1 carcinogen
the cancer risk for each birth control type
other important information you need to make informed choices

What Does It Mean to Call Hormonal Birth Control a “Carcinogen”?

The World Health Organization (WHO) classifies combined oral contraceptives (those containing both estrogen and progestin) as Group 1 carcinogens. This category includes substances for which there is sufficient evidence of carcinogenicity in humans—like tobacco and asbestos.

However, a Group 1 classification does not mean all substances within it carry the same level of risk. It simply means that a causal link has been established. For hormonal contraceptives, the actual increase in cancer risk is small, and it varies depending on the type of cancer, the formulation used, and individual health factors.

Hormonal Birth Control and Cancer

Combined Oral Contraceptives (The Pill)

These contain both estrogen and progestin and are among the most widely used forms of birth control.

Breast Cancer: Slightly increased risk while using the pill. This elevated risk declines after discontinuation and returns to baseline within about 10 years.
Cervical Cancer: Long-term use may be linked to a modest increase in risk. More research is needed to establish causality.
Ovarian & Endometrial (Uterine) Cancer: Long-term use is associated with a significantly reduced risk. This protective effect continues even after stopping.
Colorectal Cancer: Some studies suggest a potential risk reduction, though data is less conclusive.

Progestin-Only Pills (The Mini-Pill)

Research on progestin-only pills is more limited due to lower historical usage, but recent trends have increased interest.

Breast Cancer: Slight increase in risk, similar to combined pills. Risk decreases after discontinuation.
Cervical and Endometrial Cancer: Evidence is limited, but early studies suggest potential risk reduction for endometrial cancer. More research is needed.

Hormonal IUDs (e.g., Mirena, Kyleena, Liletta, Skyla)

These devices release levonorgestrel, a type of progestin, over several years.

Breast Cancer: One large study found a 40% relative increase in breast cancer risk. However, in absolute terms, the increase is small. For example, a 30-year-old woman’s risk may rise from 0.49% to 0.69% over seven years.
Other Cancers: No strong evidence links hormonal IUDs to other types of cancer. They may offer some protective effects similar to oral contraceptives, but more data is needed.

Note: Women with a history of breast cancer are generally advised to avoid hormonal IUDs and should discuss non-hormonal options with their healthcare provider.

Depo-Provera (Injection)

Breast & Cervical Cancer: Slightly increased risk, which diminishes after stopping.
Other Cancers: Data are limited but suggest potential reductions in ovarian and endometrial cancer risk.

NuvaRing (Vaginal Ring) and Ortho Evra (Patch)

Breast & Cervical Cancer: Slight increase in risk during use; returns to baseline 10 years after discontinuation.
Protective Benefits: May reduce risk of endometrial, ovarian, and colorectal cancer.

Implants (e.g., Nexplanon)

Breast Cancer: Associated with a 20–30% increase in risk.
Other Effects: More research is needed to assess impacts on other cancer types.

Weighing the Risks and Benefits

It’s essential to understand that while hormonal birth control may slightly increase the risk of some cancers, it also offers significant protective benefits against others. The overall cancer risk for many users may actually be lower than for those who do not use hormonal contraceptives.

Individual risk factors matter. These include:

Age
Family history of hormone-sensitive cancers
Personal health history
Duration and type of contraceptive use

Bottom Line: Informed Choice Is Empowered Choice

Contraception is deeply personal, and the decision to use (or discontinue) hormonal birth control should be made in consultation with a healthcare provider. Together, you can weigh: