Combined hormonal contraception
Combined hormonal contraception (CHC), or combined birth control, is a form of hormonal contraception which combines both an estrogen and a progestogen in varying formulations.
| Combined hormonal contraception | |
|---|---|
| |
| Background | |
| Type | Hormonal |
| First use |
|
| Failure rates (first year) | |
| Perfect use | 0.3% |
| Typical use | 9% |
| Usage | |
| Reversibility | on discontinuation |
| User reminders | ? |
| Advantages and disadvantages | |
| STI protection | No |
| Periods | Typically regular and lighter |
| Weight | No evidence of weight gain |
The different types available include the pill, the patch and the vaginal ring, which are all widely available, and an injection, which is available in only some countries. They work by mainly suppressing luteinising hormone (LH) and follicle-stimulating hormone (FSH) and in turn preventing ovulation.
The pill, patch, and vaginal ring are all about 93% effective with typical use. Beneficial health effects include reduced risks of ovarian, endometrial and colorectal cancers. CHC can also provide improved control of some menstrual problems. Adverse effects include a small but higher risk of venous thromboembolism, arterial thromboembolism, breast cancer and cervical cancer.