The contraceptive pill is a daily medication used to prevent pregnancy. It can be taken continuously or for 21 days out of 28 to trigger a monthly menstrual cycle. The pill works by mimicking female hormones like estrogen and progesterone, which prevent ovulation, fertilization, and the implantation of a fertilized egg. There are two main types: combined pills, which contain both estrogen and a progestative hormone, and microprogestative pills, which contain only a small amount of a single progestative hormone, such as desogestrel, levonorgestrel, or drospirenone. Combined pills carry more health risks, including a higher chance of blood clots and cardiovascular issues, compared to microprogestative pills. In 2005, the International Agency for Research on Cancer (CIRC), part of the World Health Organization (WHO), classified combined contraceptive pills as group 1 carcinogens, meaning they are known to cause cancer in humans. These pills slightly increase the risk of breast cancer, especially with long-term use exceeding five years. However, this increased risk tends to disappear after 10 years of stopping use. A French study found a rise in breast cancer cases among women under 40, though the exact reasons are not fully understood. For women at high risk of breast cancer, such as those with genetic mutations in the BRCA1 or BRCA2 genes, there is no formal rule against using hormonal contraception. However, many doctors are cautious about prescribing combined pills in this group. Genetic testing and regular gynecological check-ups are advised for these women to manage their health effectively. Women who have had breast cancer and are not menopausal should avoid hormonal contraception after treatment. Non-hormonal methods, such as the copper intrauterine device, condoms, or tubal ligation, are safer options. If menstrual cycles return after chemotherapy or hormone therapy, contraception should be restarted. Long-term use of combined pills may also increase the risk of cervical cancer, though this risk can be affected by factors like HPV infection and condom use. The widespread use of HPV vaccines is expected to lower this risk. Additionally, long-term use of combined pills may slightly raise the risk of hepatocellular carcinoma, a rare type of liver cancer. If liver adenomas are diagnosed, these pills should be stopped, and non-hormonal contraception should be used instead. Studies suggest that the contraceptive pill can lower the risk of ovarian, endometrial, and colon cancers. A 2015 British study found that using the pill for five years reduces the risk of endometrial cancer by 25%. A 2018 American study showed that taking the pill for at least 10 years can reduce the risk of ovarian cancer by 40%. A 2020 study in Cancer Research found that these protective effects can last for 15 to 35 years after stopping the pill. However, findings about colorectal cancer are mixed, with some studies showing a benefit and others not.