One of the most common questions people have about the birth control pill is whether it is safe to take for years at a time. You may have heard that you should "take a break" every few years to let your body recover, or that long-term use increases cancer risk. You may also have heard the opposite.
The short answer is that decades of research on pill safety are broadly reassuring, with nuances worth understanding. The pill is associated with reduced risk of some cancers and a modestly increased risk of others. It has no negative impact on long-term fertility. The idea that you need periodic breaks is not supported by clinical guidance.
Cancer Risk: The Full Picture
The combined pill's relationship with cancer is one of the most studied areas in all of reproductive medicine. The evidence is mixed, but the overall balance is better than many people expect.
Cancers where the pill is protective
Ovarian cancer
Landmark Research
Collaborative Group on Epidemiological Studies of Ovarian Cancer, Lancet, 2008: A pooled analysis drawing on 45 epidemiological studies involving over 100,000 women found that ever-use of the combined pill was associated with a 27% reduction in ovarian cancer risk compared to never-use. The protective effect increased with duration of use, with each additional 5 years of pill use associated with approximately 20% further risk reduction. Crucially, this protection persisted for years and even decades after stopping the pill. (Collaborative Group, Lancet. 2008;371:303-314)
The proposed mechanism involves suppression of ovulation. Each ovulation involves a small amount of epithelial disruption and repair on the ovarian surface, a process thought to contribute to malignant transformation over time. By suppressing ovulation during pill use, this repetitive disruption is reduced.
Endometrial cancer
The combined pill is also associated with substantial protection against endometrial (uterine) cancer. The same 2008 collaborative analysis found a roughly 50% reduction in endometrial cancer risk among ever-users, with stronger effects in women who used the pill for longer periods. This protection also persists for many years after stopping, providing long-term benefit that extends well beyond the period of use.
Colorectal cancer
Several studies have noted a modest reduction in colorectal cancer risk among combined pill users, though the evidence is less consistent than for ovarian and endometrial cancer and the effect size is smaller. The mechanism is not fully established.
Cancers with a modestly increased risk
Cervical cancer
Long-term combined pill use is associated with a modest increase in cervical cancer risk. A 2007 collaborative reanalysis published in The Lancet, drawing on data from 24 epidemiological studies, found that the risk increased with duration of pill use and returned toward baseline levels after stopping.
This association is importantly confounded by HPV exposure. Cervical cancer is almost entirely caused by persistent HPV infection, and pill users may be less likely to use barrier contraception, potentially increasing HPV exposure. Disentangling pill use from HPV exposure is methodologically challenging, and some researchers argue the pill's effect on cervical cancer may be partly indirect.
Regular cervical screening (smear tests) is effective at identifying precancerous changes early. Maintaining up-to-date cervical screening is the most important risk management step, regardless of pill use.
Breast cancer
Study Spotlight
Mørch et al., New England Journal of Medicine, 2017: A Danish cohort study following over 1.8 million women for up to 11 years found a relative risk of breast cancer of 1.20 among current or recent combined pill users compared to never-users. This translates to approximately 13 extra cases per 100,000 person-years of exposure. In absolute terms, the increase is small in the typical pill-using age group, where baseline breast cancer rates are low. A follow-up analysis published in PLOS Medicine in 2023 confirmed similar risk estimates. The risk appears concentrated in current and recent users and diminishes after stopping, returning toward background levels over subsequent years. (Mørch LS et al., N Engl J Med. 2017;377:2228-2239)
For the vast majority of pill users, this modest relative risk increase in a low-baseline-risk age group results in very small absolute numbers. However, it is a legitimate consideration for individuals with a family history of breast cancer or other elevated baseline risk, and it is worth discussing with a GP in that context.
Do You Need a Break From the Pill?
No. This is one of the most persistent myths in contraceptive practice and it is not supported by any clinical guideline from FSRH, NICE, RCOG, or any major body in the UK or internationally.
The pill does not accumulate in the body; it is cleared within days of stopping. There is no identified physiological benefit to stopping and restarting. FSRH guidance states that combined oral contraceptives can be used continuously until the age at which they are no longer clinically appropriate, typically around age 50.
Taking unplanned breaks also carries an obvious practical downside: any period without contraceptive cover is a period of unintended pregnancy risk.
The idea of periodic breaks appears to stem from a general cultural anxiety about long-term medication use rather than any identified clinical need. If you are considering stopping the pill for any reason, the appropriate step is a conversation with your GP about whether an alternative method might suit you better, not a period of no contraception.
Bone Density
Long-term use of the combined pill does not negatively affect bone density. This distinguishes it from the contraceptive injection (Depo-Provera, or depot medroxyprogesterone acetate), which is associated with reduced bone mineral density and is used with more caution in adolescents and those with bone density concerns.
Studies examining bone density in combined pill users compared to non-users have found no consistent evidence of bone loss. Some studies have found a modest protective effect in postmenopausal women who used the pill earlier in life, though the evidence is not strong enough to recommend the pill for this purpose alone.
Cardiovascular Risk in Long-Term Users
The combined pill is associated with a small increase in venous thromboembolism (VTE) and a very small increase in arterial events (stroke and heart attack) in certain risk groups. These risks are associated with current use rather than cumulative duration. The cardiovascular risk profile is not substantively different between someone who has taken the pill for 1 year and someone who has taken it for 10 years, all else being equal.
The key cardiovascular risk factors for pill use are not duration but individual characteristics:
Smoking, particularly over age 35 · Personal or family history of thrombosis · Migraine with aura · Obesity · Certain inherited clotting conditions such as Factor V Leiden · Hypertension
These factors are assessed at the point of prescribing and reviewed at regular check-ups. The UK Medical Eligibility Criteria for Contraceptive Use (UK-MEC) provides a systematic framework for assessing individual suitability based on medical history.
Long-term pill users should have a blood pressure check at least annually. Hypertension can develop over time for unrelated reasons, and it is a reason to reconsider the method if it becomes elevated.
Age and Long-Term Use
The appropriateness of the combined pill changes across different life stages.
For most people, the combined pill is suitable from the onset of periods through to approximately age 50. FSRH guidance suggests that at age 50 or above, switching to a progestin-only pill, IUD, or other method is preferable, as cardiovascular risk factors, including hypertension and cardiovascular disease, become more common with age.
Smoking status is the most important age-related consideration. FSRH advises against the combined pill in smokers over age 35, owing to the combined increase in stroke and myocardial infarction risk from smoking plus oestrogen-containing contraception. For non-smokers without other risk factors, the combined pill remains appropriate well into the forties.
Annual Check-Ups and What to Monitor
Long-term pill users are recommended to have an annual review with their GP or sexual health clinic. This typically includes:
- Blood pressure measurement
- Review of any new medical history, medications, or family history changes
- Discussion of whether the current method remains appropriate
- Reminder of missed pill rules and pill-drug interactions
- Cervical screening status
For most people, these reviews will continue to confirm that the pill remains suitable. For some, changes in health status will prompt a conversation about alternatives. Blood tests are not routinely required unless there are specific clinical risk factors.
Track with Estroclic
Keep an accurate record for your annual review
Long-term pill users are recommended to have an annual GP check-up. Estroclic logs every dose you take, every missed pill, and every cycle note, so you always have an accurate history of your pill use ready to bring to that conversation.
Download on AndroidFrequently asked questions
Is it safe to take the birth control pill for years?
Yes, for most people the combined pill is safe to take long-term. Decades of research show it is associated with significant protection against ovarian and endometrial cancer, a modest relative increase in breast cancer risk during current use, and a small increase in cervical cancer risk with very long-term use. Regular GP check-ups, up-to-date cervical screening, and blood pressure monitoring are the main oversight requirements.
Do you need to take a break from the pill?
No. FSRH, NICE, and other major clinical bodies do not recommend periodic breaks from the pill. There is no identified physiological benefit to stopping and restarting, and unintended breaks create periods of pregnancy risk. You can take the combined pill continuously until the age at which it is no longer clinically appropriate, typically around age 50.
Does the pill affect fertility long-term?
No. The combined pill does not cause long-term fertility problems. Extensive research comparing fertility outcomes in former pill users and women using other contraceptive methods shows no difference in conception rates. There may be a short-term delay of 1 to 3 months before ovulation resumes after stopping, but this is within the normal range.
Does the pill cause cancer?
The picture is mixed. The combined pill reduces the risk of ovarian cancer by approximately 27% and endometrial cancer by approximately 50%, with these protective effects persisting for years after stopping. It is associated with a modest relative increase in breast cancer risk during current use and a small increase in cervical cancer risk with very long-term use. For most users in the typical pill-taking age group, the overall cancer balance is broadly neutral to slightly favourable.
Does the pill affect bone density?
The combined pill does not negatively affect bone density. This distinguishes it from the contraceptive injection (Depo-Provera), which is associated with reduced bone mineral density with prolonged use and is used with more caution in adolescents and those with bone density concerns.
How long can you stay on the pill?
Most clinical guidelines, including FSRH guidance in the UK, suggest the combined pill can be used from the onset of periods until around age 50. Appropriateness is reviewed based on individual health factors, including blood pressure and smoking status, rather than a fixed duration of use. Smokers over age 35 are advised against the combined pill due to combined cardiovascular risk.
Sources
- Collaborative Group on Epidemiological Studies of Ovarian Cancer. Ovarian cancer and oral contraceptives: collaborative reanalysis of data from 45 epidemiological studies including 23,257 women with ovarian cancer and 87,303 controls. Lancet. 2008;371(9609):303-314. Landmark pooled analysis confirming 27% reduced ovarian cancer risk in ever-users, with protection increasing with duration of use and persisting for decades after stopping. pubmed.ncbi.nlm.nih.gov
- Collaborative Group on Epidemiological Studies of Cervical Cancer. Cervical cancer and hormonal contraceptives: collaborative reanalysis of individual data for 16,573 women with cervical cancer and 35,509 women without cervical cancer from 24 epidemiological studies. Lancet. 2007;370(9599):1609-1621. Found that cervical cancer risk increased with duration of combined pill use and returned toward baseline after stopping, with important confounding by HPV exposure and barrier contraceptive use noted by the authors. pubmed.ncbi.nlm.nih.gov
- Mørch LS, Skovlund CW, Hannaford PC, et al. Contemporary Hormonal Contraception and the Risk of Breast Cancer. N Engl J Med. 2017;377(23):2228-2239. Danish national cohort study of over 1.8 million women finding a relative risk of 1.20 for breast cancer among current or recent combined pill users, translating to approximately 13 extra cases per 100,000 person-years. Risk diminished after stopping. Follow-up analysis in PLOS Medicine (2023) confirmed comparable estimates. pubmed.ncbi.nlm.nih.gov
- Faculty of Sexual and Reproductive Healthcare (FSRH). FSRH Guideline: Combined Hormonal Contraception. Faculty of Sexual and Reproductive Healthcare. 2019 (updated 2023). UK clinical guideline covering long-term safety, cancer risk, cardiovascular considerations, and the absence of any clinical indication for periodic breaks from the combined pill. fsrh.org