Hormonal contraception refers to birth control methods that act on the endocrine system. Almost all methods are composed of steroid hormones, although in India one selective estrogen receptor modulator is marketed as a contraceptive. The original hormonal method—the combined oral contraceptive pill—was first marketed as a contraceptive in 1960. In the ensuing decades, many other delivery methods have been developed. The oral and injectable methods are by far the most popular. Hormonal contraception is highly effective: when taken on the prescribed schedule, users of steroid hormone methods experience pregnancy rates of less than 1% per year. Perfect-use pregnancy rates for most hormonal contraceptives are usually around the 0.3% rate or less. Currently available methods can only be used by women; the development of a male hormonal contraceptive is an active research area.
There are two main types of hormonal contraceptive formulations: combined methods which contain both an estrogen and a progestin, and progestogen-only methods which contain only progesterone or one of its synthetic analogues (progestins). Combined methods work by suppressing ovulation and thickening cervical mucus; while progestogen-only methods reduce the frequency of ovulation, most rely more heavily on changes in cervical mucus. The incidence of certain side effects differs among formulations: for example, breakthrough bleeding is much more common with progestogen-only methods. Certain serious complications occasionally caused by estrogen-containing contraceptives are not believed to be caused by progestogen-only formulations: deep vein thrombosis is one example of this.
Medical uses Hormonal contraception is primarily used for the prevention of pregnancy, but is also prescribed for the treatment of polycystic ovary syndrome, menstrual disorders such as dysmenorrhea and menorrhagia, and hirsutism.
Polycystic ovary syndrome Hormonal treatments, such as hormonal contraceptives, are frequently successful at alleviating symptoms associated with polycystic ovary syndrome. Birth control pills are often prescribed to reverse the effects of excessive androgen levels, and decrease ovarian hormone production.
Dysmenorrhea Hormonal birth control methods such as birth control pills, the contraceptive patch, vaginal ring, contraceptive implant, and hormonal IUD are used to treat cramping and pain associated with primary dysmenorrhea.
Menorrhagia Oral contraceptives are prescribed in the treatment of menorrhagia to help regulate menstrual cycles and prevent prolonged menstrual bleeding. The hormonal IUD (Mirena) releases levonorgestrel, which thins the uterine lining, preventing excessive bleeding and loss of iron.
Hirsutism Birth control pills are the most commonly prescribed hormonal treatment for hirsutism, as they prevent ovulation and decrease androgen production by the ovaries. Additionally, estrogen in the pills stimulates the liver to produce more of a protein that binds to androgens and reduces their activity.
Effectiveness Modern contraceptives using steroid hormones have perfect-use or method failure rates of less than 1% per year. The lowest failure rates are seen with the implants Jadelle and Implanon, at 0.05% per year. According to Contraceptive Technology, none of these methods has a failure rate greater than 0.3% per year. The SERM ormeloxifene is less effective than the steroid hormone methods; studies have found a perfect-use failure rate near 2% per year.
Long-acting methods such as the implant and the IUS are user-independent methods. For user-independent methods, the typical or actual-use failure rates are the same as the method failure rates. Methods that require regular action by the user—such as taking a pill every day—have typical failure rates higher than perfect-use failure rates. Contraceptive Technology reports a typical failure rate of 3% per year for the injection Depo-Provera, and 8% per year for most other user-dependent hormonal methods. While no large studies have been done, it is hoped that newer methods, which require less frequent action (such as the patch), will result in higher user compliance and therefore lower typical failure rates.
Currently, there is little evidence that there is an association between being overweight and the effectiveness of hormonal contraceptives.
Combined vs. progestogen-only While unpredictable breakthrough bleeding is a possible side effect for all hormonal contraceptives, it is more common with progestogen-only formulations.POP: IUS: Depo-Provera and Jadelle: Implanon: Most regimens of COCPs, NuvaRing, and the contraceptive patch incorporate a placebo or break week that causes regular withdrawal bleeding. While women using combined injectable contraceptives may experience amenorrhea (lack of periods), they typically have predictable bleeding comparable to that of women using COCPs.
Although high-quality studies are lacking, it is believed that estrogen-containing contraceptives significantly decrease the quantity of milk in breastfeeding women. Progestogen-only contraceptives are not believed to have this effect. In addition, while in general the progestogen-only pill is less effective than other hormonal contraceptives, the added contraceptive effect of breastfeeding makes it highly effective in breastfeeding women.
While combined contraceptives increase the risk for deep vein thrombosis (DVT – blood clots), progestogen-only contraceptives are not believed to affect DVT formation.
Side effects
Cancers There is a mixed effect of combined hormonal contraceptives on the rates of various cancers, with the International Agency for Research on Cancer (IARC) stating: "It was concluded that, if the reported association was causal, the excess risk for breast cancer associated with typical patterns of current use of combined oral contraceptives was very small." and also saying that "there is also conclusive evidence that these agents have a protective effect against cancers of the ovary and endometrium": The (IARC) notes that "the weight of the evidence suggests a small increase in the relative risk for breast cancer among current and recent users" which following discontinuation then lessens over a period of 10 years to similar rates as women who never used them, as well as "The increase in risk for breast cancer associated with the use of combined oral contraceptives in younger women could be due to more frequent contacts with doctors" Small increases are also seen in the rates of cervical cancer and hepatocellular (liver) tumours. Endometrial and ovarian cancer risks are approximately halved and persists for at least 10 years after cessation of use; "sequential oral contraceptives, which were removed from the consumer market in the 1970s, were associated with an increased risk for endometrial cancer". Studies have overall not shown effects on the relative risks for colorectal, melanoma, or thyroid cancers. Information on progesterone-only pills is less extensive, due to smaller sampling sizes, but they do not appear to increase the risk of breast cancer significantly. Most other forms of hormonal contraception are too new for meaningful data to be available, although risks and benefits are believed to be similar for methods that use the same hormones; e.g., risks for combined-hormone patches are thought to be roughly equivalent to those for combined-hormone pills.
Cardiovascular disease Combined oral contraceptives can increase the risk of certain types of cardiovascular disease in women with a pre-existing condition or already heightened risk of cardiovascular disease. Smoking (for women over 35), metabolic conditions like diabetes, obesity, and a family history of heart disease are all risk factors that may be exacerbated by the use of certain hormonal contraceptives. Oral contraceptives have also been linked to an inflated risk of myocardial infarction, arterial thrombosis, and ischemic stroke.
Blood clots Hormonal contraception methods are consistently linked with the risk of developing blood clots. However, the risk does vary depending on the hormone type or birth control method being used.
Emotional well-being Hormonal Contraceptives have not been consistently shown to affect emotional well-being negatively.Mengelkoch S, Afshar K, Slavich GM. Hormonal Contraceptive Use and Affective Disorders: An Updated Review. Open access journal of contraception. 2025;16:1-29. doi:10.2147/OAJC.S431365Doornweerd AM, Baas JMP, Montoya ER, van de Vijver I, Gerritsen L. Emotion and birth control: Emotion regulation ERPs differ based on menstrual cycle phase and hormonal contraceptive use. Psychoneuroendocrinology. 2024;170. doi:10.1016/j.psyneuen.2024.107174 Most research suggests that users do not experience meaningful changes in mood. This is true even in studies that find measurable differences in neural indicators of emotion.Zelionkaitė I, Gaižauskaitė R, Uusberg H, et al. The levonorgestrel-releasing intrauterine device is related to early emotional reactivity: An ERP study. Psychoneuroendocrinology. 2024;162. doi:10.1016/j.psyneuen.2023.106954 Some studies suggest that hormonal contraceptives may have small effects on specific aspects of well-being and that individuals who are particularly sensitive to hormonal fluctuations could be at increased risk for mood-related side effects.Doornweerd AM, Gerritsen L. 28 days later: A prospective daily study on psychological well-being across the menstrual cycle and the effects of hormones and oral contraceptives. Psychological Medicine. 2025;55:e19. doi:10.1017/S003329172400357X However, findings in this field remain inconsistent. Much of this inconsistency is due to methodological challenges, including variability in natural hormonal fluctuations across the menstrual cycle and differences in menstrual cycle phase at testing. These factors make it difficult to compare between hormonal contraceptive users and naturally cycling individuals.
Types There are two main classes of hormonal contraceptives: combined contraceptives contain both an estrogen and a progestin, and progestogen-only contraceptives that contain only progesterone or a synthetic analogue (progestin). There is also a non-hormonal contraceptive called ormeloxifene which acts on the hormonal system to prevent pregnancy.
Combined The most popular form of hormonal contraception is the combined oral contraceptive pill (COCP) known colloquially as the pill. It is taken once a day, most commonly for 21 days followed by a seven-day break, although other regimens are also used. For women not using ongoing hormonal contraception, COCPs may be taken after intercourse as emergency contraception: this is known as the Yuzpe regimen. COCPs are available in a variety of formulations.
The contraceptive patch is applied to the skin and worn continuously. A series of three patches is worn for one week each, and then the user takes a one-week break. NuvaRing is worn inside the vagina. A ring is worn for three weeks. After removal, the user takes a one-week break before inserting a new ring. As with COCPs, other regimens may be used with the contraceptive patch or NuvaRing to provide extended cycle combined hormonal contraception.
Some combined injectable contraceptives can be administered as one injection per month.
Progestogen-only The progestogen-only pill (POP) is taken once per day within the same three-hour window. Several different formulations of POP are marketed. A low-dose formulation is known as the minipill. Unlike COCPs, progestogen-only pills are taken every day with no breaks or placebos. For women not using ongoing hormonal contraception, progestogen-only pills may be taken after intercourse as emergency contraception. There are several dedicated products sold for this purpose.