Hormonal birth control isn’t categorically bad for you, but it does carry real trade-offs that vary depending on the type you use, your age, and your individual health profile. Some risks, like blood clots and a modest increase in breast cancer, are well documented. So are some genuine protective effects, including significant reductions in ovarian and endometrial cancer. The honest answer is more nuanced than a simple yes or no.
Blood Clot Risk Depends on the Type
The most serious short-term risk of hormonal birth control is venous thromboembolism, which includes deep vein thrombosis and pulmonary embolism. But the risk isn’t the same across all methods. A large nationwide cohort study published in The BMJ categorized hormonal contraceptives into risk tiers. Combined methods containing estrogen plus certain newer progestins (like drospirenone or desogestrel), the patch, and the vaginal ring carried the highest risk, roughly quadrupling the rate of blood clots compared to non-use. Other combined oral contraceptives tripled the rate.
Progestin-only pills, hormonal IUDs, and implants were in the lowest risk category, with essentially no meaningful increase in clot risk. That’s worth knowing if blood clots are your main concern: not all hormonal birth control is equal here, and switching to a progestin-only method can largely eliminate this particular danger.
To put the numbers in perspective, blood clots are still rare events even among higher-risk users. The baseline rate in young women is low, so even a fourfold increase translates to a small absolute number. But if you smoke, have a family history of clotting disorders, or are over 35, those multipliers start to matter more.
Breast Cancer Risk Goes Up Slightly
Hormonal birth control does increase breast cancer risk, but the size of the increase is smaller than many people fear. A large Danish study found that women currently using or recently using combined hormonal contraceptives had about a 20% higher risk of breast cancer compared to women who had never used them. An older pooled analysis of over 150,000 women found a 24% increase in current users, with no additional increase the longer someone stayed on the pill.
The reassuring part: this risk fades after stopping. Within 10 years of discontinuing oral contraceptives, there’s no detectable increase in breast cancer risk. And the lifetime risk increase for women who have ever used the pill, compared to those who never did, is about 7%.
It Protects Against Other Cancers
The cancer story isn’t one-sided. Oral contraceptives substantially reduce the risk of ovarian cancer and endometrial cancer, two cancers that are harder to detect early and often more dangerous. These protective effects are well established across decades of research and, notably, they persist for years after you stop taking the pill. For women with a family history of ovarian cancer in particular, this protection can be clinically meaningful.
Depression Risk Is Real but Time-Limited
One of the most common concerns about hormonal birth control is its effect on mood, and the data supports taking this seriously. A large study found that women who started oral contraceptives had a 79% increased risk of depression during their first two years of use compared to peers who never used them. Adolescents who started at age 20 or younger were hit harder, with a 95% increased risk during that same window. Women who began after age 20 had a 92% increase in depressive symptoms in the first two years.
Here’s the important context: the elevated risk is concentrated in those early years. Looking at lifetime risk, women who had ever used oral contraceptives had only a 5% higher rate of depression overall compared to never-users. This suggests the mood effects are most intense during the adjustment period and tend to level off. Still, if you’re noticing significant mood changes in the first months on a new hormonal method, that’s a recognized pattern and worth discussing with your provider rather than pushing through.
Weight Gain Is Mostly a Myth, With One Exception
Combined oral contraceptives and the patch are weight neutral. A Cochrane review of 49 trials found no additional weight gain compared to a sham method, no perception of extra weight gain, and no increase in people quitting because of weight. Progestin-only pills and implants are similar, with either no change or a modest gain of about 4.4 pounds over six to 12 months.
The exception is the injectable shot (Depo-Provera). Users gained an average of 13.7 pounds over five years, which is a more substantial change. If weight is a concern for you, the shot is the one method where the evidence clearly supports that worry.
Bone Density Loss From the Shot
The injectable also stands out for bone health. Depo-Provera users lose about 1.12% of hip bone density per year and 0.87% at the spine, compared to negligible changes in non-users. The good news is that this loss is largely reversible. Within two and a half years of stopping the shot, bone density values in most women returned to levels similar to non-users.
The exception was women aged 18 to 21, whose bone density hadn’t fully caught up even two and a half years after stopping. Since these are critical years for building peak bone mass, long-term use of the shot during late adolescence deserves more careful consideration than it might at age 30.
Effects on Sex Drive
Lower libido is one of the more frustrating side effects some women experience on hormonal birth control, and it’s biologically plausible. Hormonal methods can increase levels of a protein that binds to testosterone, reducing the amount of free testosterone available in your body. Testosterone plays a role in sex drive for all genders.
That said, most people using hormonal methods don’t notice a change in sex drive or arousal. For those who do, the effect varies widely. Some women experience the opposite, finding that reduced anxiety about pregnancy or lighter periods actually improves their sex life. If you’ve noticed a significant drop, switching formulations or method types often helps.
Vitamin B12 Drops but Probably Doesn’t Matter
Both oral contraceptives and the injectable shot lower vitamin B12 levels. One study found a sharp decrease during the first six months: pill users saw B12 drop by about 20% of their baseline value, and shot users by about 13%. However, researchers concluded that this decrease doesn’t appear to be clinically significant or affect bone mineral density. If you’re already at risk for B12 deficiency (for instance, if you follow a vegan diet), it’s worth monitoring, but for most users this isn’t a health concern on its own.
Fertility Returns Faster Than You’d Think
A common worry is that years of hormonal birth control will delay your ability to get pregnant. A study published in The BMJ tracked how quickly fertility returned across different methods. IUD and implant users returned to normal fertility within about two menstrual cycles. Pill and vaginal ring users took about three cycles. Patch users took four. The shot had the longest delay at five to eight cycles, which makes sense given how the injectable works as a slow-release hormone.
Importantly, how long you used any of these methods had no effect on how quickly fertility returned. Someone who took the pill for 10 years didn’t wait longer than someone who took it for two. For all hormonal methods, the delays were short-term.
How to Think About the Trade-Offs
The risks of hormonal birth control are real but generally small in absolute terms for healthy young women. The biggest variables are which method you choose and your individual risk factors. Combined methods with estrogen carry higher clot risk. The injectable shot is the outlier for weight gain and bone density. Depression risk is highest in the first two years and in younger users. Progestin-only methods like hormonal IUDs, implants, and mini-pills sidestep several of the most-cited concerns, including blood clots.
What often gets lost in the “is it bad for you” framing is that hormonal birth control also offers real health benefits beyond contraception: reduced ovarian and endometrial cancer risk, lighter periods, less menstrual pain, and management of conditions like endometriosis and PCOS. Whether the trade-offs make sense depends on your health history, which specific method you’re considering, and what matters most to you.