For the vast majority of people, birth control is safe. Every hormonal and device-based contraceptive sold in the U.S. has been approved by the FDA after demonstrating both safety and effectiveness. That said, “safe” doesn’t mean “zero risk.” Different methods carry different trade-offs, and some health conditions can tip the balance. Understanding those specifics helps you choose the method that fits your body.
Blood Clot Risk: Small but Real
The most talked-about serious risk of combined hormonal birth control (the pill, patch, or ring containing both estrogen and progestin) is blood clots, specifically venous thromboembolism (VTE). For women ages 15 to 49 who don’t use hormones, the baseline rate of blood clots is roughly 2 to 4 per 10,000 people per year. Combined pills raise that risk by about 3.5 times, which sounds dramatic but translates to an absolute risk of roughly 5 to 12 per 10,000 per year depending on the formulation. For a healthy teenager, the annual risk works out to about 0.05%.
To put that in perspective, pregnancy and the postpartum period increase clot risk by 4 to 10 times over baseline. So preventing an unplanned pregnancy with the pill actually avoids a situation that carries a higher clotting risk than the pill itself. Heart attacks and strokes tied to birth control are rarer still, though smoking, obesity, and high blood pressure all raise the odds.
Progestin-only methods (the mini-pill, hormonal IUD, implant, and injection) do not carry the same elevated clot risk because they lack estrogen. If you have a personal or family history of blood clots, these are typically the options your provider will steer you toward.
Migraine With Aura Changes the Equation
One group faces a meaningfully higher stroke risk on combined hormonal contraceptives: people who get migraines with aura. Compared to someone with neither migraines nor hormonal birth control use, having migraine with aura alone roughly triples the odds of ischemic stroke. Adding a combined pill on top pushes that to about a sixfold increase. For migraines without aura, the added risk from combined contraceptives is much smaller. This is why providers ask about your headache history before prescribing. If you experience visual disturbances, numbness, or speech changes before your migraines, progestin-only or non-hormonal methods are safer choices.
Breast Cancer Risk Is Small, and Offset by Other Protections
Hormonal birth control does slightly increase breast cancer risk. A 2024 study in JAMA Oncology found that ever using any hormonal contraceptive raised breast cancer risk by about 24%, which sounds alarming until you see the absolute numbers: that translates to roughly 1 additional breast cancer case per 7,752 users. Both combined and progestin-only formulations contributed, with longer use (5 to 10 years) showing more pronounced increases.
The flip side is striking. Combined oral contraceptives reduce ovarian cancer risk by about 11% for every year of use. After five years on the pill, ovarian cancer risk drops by more than half. Endometrial cancer risk drops by a similar margin, and that protection persists for up to 15 years after you stop taking the pill. For people with a family history of ovarian or endometrial cancer, these reductions can be clinically significant.
Mood and Depression
The link between hormonal birth control and mood changes has been debated for decades, but large cohort studies now support a real connection. A population-based study found that during the first two years of oral contraceptive use, the rate of depression was about 79% higher compared to people who had never used them. Adolescents were especially affected, with a 95% increase in depression rates during that window. The elevated risk diminished over time but didn’t disappear entirely. Lifetime depression risk remained about 5% higher among people who had ever used oral contraceptives.
A sibling analysis within that same study strengthened the case that the relationship is causal rather than coincidental. When researchers compared sisters, one who used the pill and one who didn’t, the pill-using sibling’s own use predicted her depression diagnosis independently of her sister’s use. This isn’t a reason to avoid birth control, but it is a reason to pay attention to your mood in the first few months after starting a new method. If you notice persistent sadness, loss of interest, or emotional flatness, switching formulations or methods often helps.
IUD Safety: Perforation and Expulsion
Intrauterine devices are among the most effective and lowest-maintenance options, but they carry their own set of risks. The most serious is uterine perforation, where the device pushes through the uterine wall. This is uncommon: the five-year cumulative incidence is about 0.6% for both hormonal and copper IUDs. It usually happens during or shortly after insertion and, when caught, is correctable.
Expulsion, where the IUD partially or fully slips out, is more common at roughly 4.5% to 4.8% over five years for both types. You won’t always feel it happen, which is why checking for the IUD strings periodically matters. Neither complication affects long-term fertility.
The Injection and Bone Density
The contraceptive injection (given every three months) carries a unique concern. The FDA’s label includes a warning that it can cause significant bone mineral density loss, with greater loss the longer you use it. This is especially relevant for adolescents and young adults, whose bones are still building toward their peak density. After stopping the injection, bone density partially recovers over about two years, but longer use is associated with less complete recovery. For this reason, many providers recommend limiting injection use to two years when other options are available.
Fertility Returns After Stopping
One of the most persistent worries about birth control is that it might cause lasting infertility. The evidence is reassuring. A systematic review pooling data across all methods found that 83% of people became pregnant within 12 months of stopping contraception. Broken down by method: about 87% of former pill users conceived within a year, 85% of former IUD users, 75% of implant users, and 78% of injection users. The slightly lower rate for injections reflects the fact that the hormone takes longer to clear the body, not permanent damage. Duration of use made no difference. Whether someone used birth control for one year or ten, fertility returned at the same rate.
How Risk Varies by Method
Not all birth control carries the same risk profile, and knowing the differences helps you match a method to your health history.
- Combined pills, patch, ring: Slight increase in blood clot risk, small breast cancer increase, substantial ovarian and endometrial cancer protection. Not recommended for people with migraine with aura, uncontrolled high blood pressure, or a history of clots.
- Progestin-only pill: No added clot risk. Similar small breast cancer increase. Safer for people who can’t use estrogen.
- Hormonal IUD: Very low systemic hormone levels. Minimal clot risk. Small perforation and expulsion risk. Effective for 3 to 8 years depending on the brand.
- Copper IUD: Entirely hormone-free, so no hormonal side effects at all. Can cause heavier periods. Similar perforation and expulsion rates to hormonal IUDs.
- Implant: Progestin-only, so no estrogen-related clot risk. Small breast cancer increase similar to other hormonal methods. Effective for 3 to 5 years.
- Injection: Progestin-only. Unique bone density concern with long-term use. Slightly longer delay in fertility return after stopping.
The safest method for you depends on your personal medical history, your age, and which side effects matter most. For a healthy person with no risk factors, every FDA-approved method falls well within the range of “safe.” The serious complications, while real, are rare, and for most people the health risks of an unintended pregnancy are considerably higher than the risks of preventing one.