Combined hormonal contraception

Combined oral contraception is now available as oral, transdermal, vaginal and injectable preparations. Only the pill and patch are currently marketed in the UK. Most of the data come from the oral preparation (the combined pill), which has been marketed for more than 40 years and used by millions of women. Used perfectly, combined hormonal contraception is highly effective (failure rate 1/1000), because it works by inhibiting ovulation. In typical use, however, mistakes are made, and pill failure rates are about 8%. Serious cardiovascular side-effects (heart attack, stroke and venous thromboembolism) are rare. The risk of venous thromboembolism varies with the type of progestogen. Breast and cervical cancer are both increased in users, though the absolute risk is small. Prescribing should not be over-medicalized.