Does Birth Control Cause Breast Cancer? What the Risk Actually Means
You see a headline saying hormonal birth control increases breast cancer risk by around 20%. Naturally, your next thought is something along the lines of, “Excuse me, twenty percent?”
That number is real. It is also very easy to misunderstand.
It doesn’t mean 20% of women who use the pill, implant, injection, or hormonal IUD will develop breast cancer. It means breast cancer is diagnosed slightly more often in women currently or recently using hormonal contraception than in women who are not.
And once we start looking at the numbers, your age, the contraceptive you use, how long you use it, and your own breast cancer history all become important.
A few parts of this conversation are also easy to miss. Hormonal IUDs are part of the research too, and having breast cancer in your family is not the same as having had breast cancer yourself.
So, let’s sort out what we actually know, without pretending the risk is zero and without turning a percentage into something scarier than it is.
Before We Talk Risk, Let’s Talk About the Different Types of Birth Control and Breast Cancer
Before we can make sense of the risk, we need to be clear about what we are actually talking about. Birth control can be hormonal or non-hormonal, and breast cancer itself is not one single disease. Some breast cancers respond to hormones, while others do not. Understanding those basics makes the rest of the discussion much easier to follow, and stops very different things from being lumped together under the word “hormonal”.
Contraceptive Types: Hormonal and Non-Hormonal
Most of the breast cancer research discussed in this article looks at hormonal contraception. This includes combined methods that contain both oestrogen and progestogen, such as many birth control pills, the contraceptive patch, and the vaginal ring. It also includes progestogen-only methods, such as the mini pill, contraceptive injection, Implanon, and hormonal IUDs such as Mirena.
Non-hormonal contraception works without releasing these hormones. The copper IUD is the main long-acting option in this group, while condoms are another familiar example.
This distinction is important because the breast cancer research we are about to unpack isn’t related to every form of contraception.
Not sure how the different methods compare? Read our guide on contraception in South Africa.
Breast Cancer Types: A Quick Guide Before We Talk Risk
Breast cancer is not one single diagnosis. Different breast cancers can behave in different ways, including in how they respond to hormones.
Some breast cancer cells have receptors that respond to oestrogen or progesterone. These are called hormone receptor-positive cancers. Others make too much of a protein called HER2, and some have neither hormone receptors nor HER2, which is where the term triple-negative breast cancer comes from. A cancer can also be both hormone receptor positive and HER2 positive.
You do not need to memorise any of those labels. What’s important for this conversation is that not every breast cancer responds to hormones in the same way. That is one reason the relationship between hormonal contraception and breast cancer is more complicated than “hormones cause cancer”.
One important point, the breast cancer risk linked with hormonal contraception is not limited to hormone-sensitive breast cancers. Research looking at different breast cancer types has produced mixed results, including associations with some hormone receptor-negative and triple-negative cancers too. So the word “hormonal” on both sides does not mean there is a direct connection between the two.
The National Cancer Institute explains these breast cancer markers in more detail if you would like to read further.
So, What Is the Breast Cancer Risk with Hormonal Birth Control?
The answer most women want first is this: hormonal birth control is linked with a small increase in breast cancer risk. Not zero, but also nowhere near as frightening as some of the numbers can sound when you first see them.
You may have come across figures saying the risk is around 20% higher. If your brain immediately translated that into “20% of women on birth control get breast cancer”, you are definitely not the only one.
That is not what it means.
Does Birth Control Increase Breast Cancer Risk by 20%?
Think of it this way. If 10 women out of 10,000 would normally develop something, increasing that risk by 20% would take the number to about 12 women out of 10,000.
That is the difference between relative risk, the percentage you tend to see in headlines, and your actual chance of something happening.
One large study found a 24% higher breast cancer risk among hormonal contraception users. When the researchers converted that percentage into actual women, it worked out to around 13 extra breast cancer diagnoses for every 100,000 users each year, or roughly one additional case for every 7,752 women using hormonal contraception.
The risk is there. It is just much smaller than the words “24% higher” can make it feel.
Breast Cancer Risk on Birth Control Looks Very Different at 20 and 40
Your chance of developing breast cancer is much lower when you are 20 than when you are approaching 40. So adding a small percentage to those two starting points does not give you the same result.
For women who used the pill between 16 and 20, there is an estimated 8 additional breast cancers per 100,000 women over the following 15 years. For women who used it between 35 and 39, that estimate rose to around 265 additional cases per 100,000 women over the same period.
The pill doesn’t suddenly become far more dangerous on your 35th birthday.
Breast cancer itself becomes more common as we get older, so the same percentage increase is being added to a bigger starting risk. And that’s one of the things you need to remember. “Hormonal birth control increases breast cancer risk” is true, but it is only half the information you need.
How much that matters to you depends on where your risk started in the first place.
Does Breast Cancer Risk Differ by Birth Control Method?
Not every hormonal contraceptive contains the same hormone, the same dose, or delivers it in the same way. And newer research suggests the breast cancer association may not be identical across every method.
We cannot rank contraceptives from lowest to highest breast cancer risk, but the actual method does make a difference. Breast cancer risk is also only one part of choosing contraception.
Does the Birth Control Pill Increase Breast Cancer Risk?
For both the combined pill and progestogen-only pill, current or recent use has been linked with a small increase in breast cancer risk.
The risk also does not appear to be identical across every pill. Some newer research has found different risk estimates depending on the particular progestogen used. That is not enough information to choose a pill based on breast cancer risk alone. Your other health factors still need to be considered.
Not sure what type of pill you take? Our guide to birth control pills in South Africa explains the different types and common brands.
Does the Contraceptive Injection Increase Breast Cancer Risk?
When contraceptive injections are grouped together, research has found a small increase in breast cancer risk. But when individual injections are looked at separately, the results differ.
Depo Provera, the three-month contraceptive injection, did not show a clear increase in one large study, while other research looking at injectable contraception more broadly has found an increase.
So, we cannot confidently give every contraceptive injection exactly the same breast cancer risk.
Using an injection and not quite sure which one? See the difference between the 2-month and 3-month contraceptive injections.
Does Implanon Increase Breast Cancer Risk?
The Implanon contains a progestogen that is released slowly from the small rod in your arm. Current or recent implant use has been linked with a higher breast cancer risk in some large studies.
Because Implanon is commonly used by younger women, you need to remember the age discussion from earlier. A relative increase on a low starting risk can still mean a small number of additional cases.
Our Implanon guide covers how it works, bleeding changes, side effects, and what to expect in much more detail.
Does Mirena Increase Breast Cancer Risk?
The Mirena is probably the method that causes the most confusion here. Because the hormone works mainly inside the uterus, many women assume it has nothing to do with breast cancer risk. But it’s not that simple.
Mirena releases levonorgestrel. Most of its contraceptive effect happens inside the uterus, but the hormone is not completely confined there. Hormonal IUD use has been linked with a small increase in breast cancer risk in several large studies.
So although Mirena works mainly inside the uterus, it still belongs in the hormonal contraception and breast cancer conversation.
If you are considering Mirena, our Mirena birth control guide covers insertion, bleeding, side effects, duration, and what to expect.
What About the Contraceptive Patch and Vaginal Ring?
The patch and vaginal ring are hormonal too, but we have less breast cancer research on them than we do on the pill. That makes it harder to give either method a reliable individual percentage.
The vaginal ring did not show a clear increase in studies, but that doesn’t mean we can confidently call it safer for breast cancer. There were fewer users and less long-term information available for some of these methods.
The same caution applies to the patch.
If you use Evra or are considering it, our Evra contraceptive patch guide explains how it works and how it compares with other options.
Does the Copper IUD Increase Breast Cancer Risk?
The copper IUD does not contain hormones, so it does not create the hormonal exposure being discussed in the studies above. That is also why the copper IUD is commonly considered when hormonal contraception is not appropriate, including for women with current breast cancer.
If you are considering a non-hormonal option, our Copper IUD guide for South Africa explains what it is like in real life.
What Are Your Non-Hormonal Birth Control Options If Breast Cancer Risk Worries You?
If you would rather avoid hormonal contraception altogether, you do have options.
The copper IUD is the main long-acting reversible choice. It contains no hormones and is also one of the most effective forms of contraception, with fewer than 1 pregnancy per 100 users in the first year.
Condoms are hormone-free too, with the added benefit of helping protect against sexually transmitted infections. Their effectiveness depends much more on using them correctly every time.
Fertility awareness methods are another hormone-free option, but they need much more day-to-day attention. Depending on the method, you track things such as cycle dates, cervical mucus, or temperature and avoid unprotected sex during fertile days. They are generally less forgiving of missed or incorrectly identified fertile days than an IUD.
And if you are finished having children, permanent contraception, such as tubal surgery or a partner’s vasectomy, avoids hormonal contraception altogether. These methods are intended to be permanent, so they need a very different conversation before going ahead.
Avoiding hormonal contraception does not mean giving up reliable birth control. If you want something long-acting, reversible, and hormone-free, the copper IUD is usually the first option worth discussing.
Not sure which birth control option makes the most sense for you? See our contraceptive options.
Does Breast Cancer Risk Increase the Longer You Use Hormonal Birth Control?
How long you have used hormonal birth control does seem to make a difference, but there isn’t a magic year where a method suddenly becomes unsafe.
The general pattern is that the longer hormonal contraception is used, the more the breast cancer association appears to increase. In one recent study, the increase was smaller during the first year of use and higher among women who had used hormonal contraception for five to ten years.
And this is probably where many women find themselves.
You start the pill at 19 because you need reliable contraception. It works, life gets busy, years pass, and suddenly you are 35 and still collecting the same prescription without ever really thinking about it again.
What worked for you at 19 may still suit you perfectly at 35. Or your health, periods, family plans, or preferences may have changed. That is why contraception should be revisited rather than being a once-off decision.
Does Breast Cancer Risk Go Down After You Stop Birth Control?
The good news is that the small increase in breast cancer risk does not seem to stay with you forever.
It is highest while you are using hormonal contraception and for a while after stopping, then gradually falls over time. By around ten years after stopping the pill, studies no longer show the same added risk seen during current or recent use.
So if you used the pill through your twenties, that does not mean you carry the same added risk for life. It fades with time.
Can You Use Birth Control With a Family History of Breast Cancer?
If breast cancer runs in your family, hormonal contraception isn’t necessarily off the table. Having a mum, sister or grandmother who has had breast cancer is something you should mention, but family history is not treated the same way as having breast cancer yourself.
Where the conversation changes is when that family history starts to look stronger.
A mum diagnosed at 38, several close relatives with breast or ovarian cancer, or a known BRCA gene change in the family can point to a higher personal risk. In that situation, the average numbers we have been discussing may not tell the whole story for you.
A strong or unusual family history is important to bring up when you choose or review your contraception, because your own starting risk may be different from the average woman in the studies.
What If BRCA Runs in Your Family?
BRCA1 and BRCA2 stand for Breast Cancer gene 1 and gene 2. We all have these genes. Their job is to help repair damaged DNA. The important part is whether someone has inherited a harmful change.
You would usually only know that you carry a BRCA1 or BRCA2 change if you have had genetic testing, often using a blood or saliva sample. Testing is more likely to be discussed when there is a strong family history, such as breast cancer at a younger age, several relatives with breast or ovarian cancer, male breast cancer, or a known BRCA change in the family.
Having a BRCA change is different from having one relative who has had breast cancer. Your starting cancer risk is already different, so contraception needs a more individual discussion.
Can You Use Hormonal Birth Control If You Have Had Breast Cancer?
If you have had breast cancer, the contraception conversation changes. That is very different from having a mum or sister who has had it.
With current breast cancer, hormonal methods are generally avoided because some breast cancers can respond to hormones. A copper IUD is often considered because it does not release hormones.
If you were treated for breast cancer in the past, it is still not a case of going back onto whichever method you used before. How long ago you were treated, the type of breast cancer you had, and the treatment you received all matter.
This is one situation where contraception should be chosen with your own cancer history in mind.
So, When Should You Review or Change Your Birth Control?
So when does all of this actually change what you do? There are a few situations where your contraception needs another look.
Health Changes That Can Mean It Is Time to Change Birth Control
A change in your health can mean a contraceptive that once suited you is no longer the right choice for you. That includes a breast cancer diagnosis, a new medical condition that affects whether your method is safe, or side effects that have become difficult to live with.
Your age, medications, periods, pregnancy plans, and personal preferences can change too. Sometimes the reason to switch is medical. Sometimes your contraception just no longer suits your life.
A Change in Your Family Breast Cancer History
If your family history changes, your contraception needs reviewing too.
That might mean your mum or sister has recently been diagnosed with breast cancer, several close relatives have now been affected, or someone in the family has tested positive for BRCA1 or BRCA2.
Those changes can mean your own breast cancer risk is higher than previously thought, which is a good reason to review whether your current contraception still suits you.
A New Breast Lump or Breast Change
A new lump, nipple change, skin dimpling, unusual discharge, or another breast change needs to be checked properly rather than trying to manage it by changing your contraception yourself.
If an investigation does lead to a breast cancer diagnosis, then your contraception will need to be reviewed as part of your care.
Not sure what breast changes to watch for? Read our guide to breast cancer signs and breast checks in South Africa.
A Breast Cancer Diagnosis
If you are diagnosed with breast cancer, your contraception needs to be reviewed as part of your care. Hormonal methods are generally avoided with current breast cancer, while non-hormonal options such as the copper IUD may be considered.
Can the Birth Control Pill Lower the Risk of Other Cancers?
The pill has been linked with a small increase in breast cancer risk during current or recent use, but it is also associated with a lower risk of ovarian, endometrial, and colorectal cancer. The reduction is particularly noticeable for ovarian and endometrial cancer, and it can last for many years after you stop taking the pill.
One cancer risk doesn’t cancel out another. But contraception and cancer are not as simple as “hormones are good” or “hormones are bad.”
The pill can be linked with a small increase in one cancer risk while being linked with lower risks of others, which is exactly why your contraception choice should be looked at as a whole.
While we are talking about cancer, a Pap smear can pick up abnormal cervical cell changes before they develop into cervical cancer. Read why every woman with a cervix needs regular Pap smears.
So, Should You Stop Your Birth Control Because of Breast Cancer Risk?
Breast cancer risk is one part of the contraception decision. For most women, the increase linked with hormonal contraception is small, but your age, the method you use, how long you have used it, and your personal and family history can change how much that risk matters to you.
If your health or breast cancer risk has changed since you chose your contraception, that is a good time to review your options. And if avoiding hormonal exposure is simply your preference, that is a reasonable reason to discuss non-hormonal options too.
If You Are Still Comparing Methods
Start with our guide to choosing contraception or browse the contraception options available at Mums & Bums.
And if you would rather talk it through properly, you do not need to arrive already knowing which pill, implant or IUD you want.
At Mums & Bums in Centurion, we can review your medical history, what you want from contraception, and the methods that suit you before deciding on the next step.
Frequently Asked Questions About Birth Control and Breast Cancer
Does birth control cause breast cancer?
Hormonal birth control is linked with a small increase in breast cancer diagnoses during current or recent use, but this does not prove that contraception directly causes breast cancer. The actual increase is small for most younger women and depends partly on your age and starting breast cancer risk.
How much does birth control increase breast cancer risk?
Current or recent hormonal contraception has been linked with roughly a 20% to 30% increase in relative breast cancer risk. The actual increase is much smaller. For example, five years of pill use was estimated to add about 8 cases per 100,000 women starting at ages 16 to 20.
Does breast cancer risk go down after stopping birth control?
Yes. The small increase linked with current or recent hormonal contraception gradually falls after stopping. For oral contraceptives, research has found no additional breast cancer risk more than about ten years after stopping compared with women who had not used them.
Does Mirena increase breast cancer risk?
Hormonal IUDs such as Mirena have been linked with a small increase in breast cancer risk in some observational studies. Mirena releases levonorgestrel, and although most of its contraceptive effect occurs inside the uterus, the hormone is not completely confined there.
Does Implanon increase breast cancer risk?
Some large studies have linked current or recent contraceptive implant use with a small increase in breast cancer risk. Implanon contains a progestogen called etonogestrel. Because implants are commonly used by younger women, the actual number of additional breast cancers remains small at younger ages.
Can I use hormonal birth control if my mum or sister had breast cancer?
Usually, yes. A family history of breast cancer on its own does not rule out hormonal contraception. If several close relatives have had breast or ovarian cancer, someone was diagnosed unusually young, or BRCA1 or BRCA2 runs in the family, your personal risk deserves a closer look.
What birth control can I use if I want to avoid hormones?
Non-hormonal options include the copper IUD, condoms, fertility awareness methods, and permanent contraception. The copper IUD is the main long-acting reversible option and does not release hormones, so it sits outside the hormonal exposure discussed in breast cancer studies.
Should I stop birth control because of breast cancer risk?
For most women, the small increase in breast cancer risk alone is not a reason to suddenly stop hormonal contraception. A review becomes more relevant if you are diagnosed with breast cancer, your family history changes, you learn that you carry BRCA1 or BRCA2, or you would simply prefer a non-hormonal method.
Can the birth control pill lower the risk of other cancers?
Yes. Oral contraceptive use is associated with a lower risk of ovarian, endometrial, and colorectal cancer, even though current or recent pill use is linked with a small increase in breast cancer risk. Protection against ovarian and endometrial cancer can continue for years after stopping the pill.
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