Birth control is most commonly used to prevent pregnancy, but it serves a surprisingly wide range of medical purposes. Millions of people use hormonal birth control to manage painful periods, treat acne, reduce symptoms of conditions like endometriosis and PCOS, and even lower the long-term risk of certain cancers. Understanding the full scope of what birth control can do helps explain why it’s one of the most frequently prescribed medications in the world.
Pregnancy Prevention
The primary use of birth control is preventing pregnancy, and it does this through several mechanisms working together. Hormonal methods suppress the development of eggs and prevent ovulation. They also thicken cervical mucus, creating a barrier that sperm can’t easily penetrate. These two effects combined make hormonal birth control highly effective when used consistently.
How well it works depends heavily on the method. The most effective options are long-acting ones that don’t require daily attention. The implant and hormonal IUDs have failure rates below 1%, meaning fewer than one user out of 100 becomes pregnant in a typical year. The copper (non-hormonal) IUD is similarly effective at 0.8%. Pills, patches, and vaginal rings are effective in theory but more forgiving of human error in practice: about 7 out of 100 users become pregnant in a typical year because of missed doses or inconsistent use. For comparison, male condoms have a typical-use failure rate of 13%.
Period Regulation and Heavy Bleeding
Hormonal birth control is a go-to treatment for irregular, heavy, or painful periods. By supplying steady levels of hormones, it overrides the body’s natural fluctuations and creates predictable, lighter cycles. For people whose periods are unpredictable or debilitating, this alone can be life-changing.
Some people use continuous dosing, skipping the placebo pills entirely, to eliminate their period altogether. This is common among athletes: a study of elite female athletes in Denmark found that 57% used hormonal contraceptives, and 60% of those on the pill reported using it continuously to skip periods and avoid symptoms that could interfere with training and competition. Continuous use is medically safe for most people and increasingly recommended when monthly bleeding isn’t desired.
Endometriosis Pain Relief
Endometriosis occurs when tissue similar to the uterine lining grows outside the uterus, causing chronic pain, painful periods, pain during sex, and sometimes pain during bowel movements. Hormonal birth control helps by thinning this tissue and reducing cell growth in the misplaced implants.
A Cochrane review of clinical trials found that people taking the pill reported meaningful reductions in menstrual pain compared to placebo. The benefits extended beyond cramping. Participants also reported less pain during sex and less pain during bowel movements. While birth control doesn’t cure endometriosis, it slows the progression and makes daily life significantly more manageable for many people with the condition.
Managing PCOS Symptoms
Polycystic ovary syndrome (PCOS) is one of the most common hormonal disorders, and combined oral contraceptives are the first-line treatment for managing its symptoms. PCOS causes irregular periods, and left untreated, the lack of regular cycles can lead to a thickening of the uterine lining that raises the risk of endometrial problems over time. The pill restores regular shedding and protects the lining.
PCOS also drives excess androgens (male-type hormones), which cause acne, excess facial or body hair, and hair thinning. Combined oral contraceptives counter these effects by lowering androgen levels. For many people with PCOS, birth control addresses multiple frustrating symptoms with a single prescription.
Acne Treatment
You don’t need a PCOS diagnosis for birth control to help with acne. Hormonal acne is driven by androgens that increase oil production in the skin, and combined oral contraceptives work against this by reducing the amount of free androgens circulating in the body. The estrogen component boosts a protein that binds up androgens, while certain types of progestin in the pill have direct anti-androgenic effects.
Some formulations are specifically designed for this purpose. Pills containing the progestin drospirenone are particularly effective because drospirenone itself has anti-androgenic properties. Results aren’t instant: most people need two to three months before they see noticeable skin improvements, since the hormonal shift takes time to reduce oil production and clear existing breakouts.
Premenstrual Dysphoric Disorder (PMDD)
PMDD is a severe form of premenstrual syndrome that causes intense mood swings, depression, irritability, and physical symptoms in the week or two before a period. It’s triggered by the hormonal shifts of ovulation, which is why it doesn’t occur during pregnancy or after menopause. Birth control that suppresses ovulation can break this cycle.
One specific formulation, a pill containing 20 micrograms of estrogen and 3 milligrams of drospirenone taken on a 24-day active/4-day inactive schedule, is the only oral contraceptive approved by the FDA specifically for PMDD. Multiple randomized trials found it significantly reduced PMDD symptoms compared to placebo. A Cochrane review confirmed the benefit, though it noted that placebo also had a marked effect, which is common in mood-related conditions. Not all pill formulations help equally: a trial of a different progestin taken continuously showed no significant improvement over placebo, suggesting the specific hormone and dosing schedule matter.
Cancer Risk Reduction
One of the lesser-known benefits of oral contraceptives is a significant reduction in the risk of endometrial and ovarian cancers. The protective effect is dose-dependent, meaning the longer someone uses the pill, the greater the reduction.
A large meta-analysis of 56 studies found that any use of oral contraceptives was associated with a 39% lower likelihood of developing endometrial cancer. Using the pill for five or more years dropped that to a 61% reduction, and using it for ten or more years was linked to a 69% reduction compared to people who never used oral contraceptives. This protective effect persists for years after stopping the pill. Research also shows reduced risk of ovarian and colorectal cancers with long-term use.
Perimenopause Symptom Management
During the years leading up to menopause, hormone levels fluctuate unpredictably, causing irregular periods, heavy bleeding, and hot flashes in 70 to 80% of perimenopausal people. Combined oral contraceptives smooth out these fluctuations, controlling bleeding patterns and reducing vasomotor symptoms like hot flashes and night sweats.
There’s also a bone health benefit. After age 40, bone mineral density decreases by about 1% per year. Using oral contraceptives during this period helps maintain bone density. People who take the pill for at least six years before menopause show significantly higher bone density in the hip and spine afterward, and starting the pill after age 40 has been linked to a 30% reduction in postmenopausal hip fracture risk. Since perimenopausal people can still become pregnant (cycles are irregular, not absent), the pill also serves its original contraceptive purpose during this transition.
Menstrual Suppression for Gender-Affirming Care
For transgender men and nonbinary individuals, menstruation can be a significant source of gender dysphoria. Several forms of birth control are used specifically to suppress periods in this context, including hormonal IUDs, injectable progestins, progestin-only pills, and combined hormonal methods. The World Professional Association for Transgender Health recommends offering menstrual suppression to adolescents as part of gender-affirming care. These methods can also address irregular bleeding that sometimes occurs in people taking testosterone, providing both cycle control and contraception when needed.