Hormonal contraceptives

Hormonal contraceptives are the most effective method of preventing pregnancy, and are associated with many health benefits that result from avoiding pregnancy and the termination of unwanted pregnancies.  In addition, the hormonal contraceptive can reduce menstrual blood loss, relieve painful menstruation and may reduce the incidence of ovarian and endometrial cancer. 

Hormonal contraceptives are available as combined (oestrogen plus progestogen) pills and patches or as progestogen-only pills, injections, implants and intra-uterine devices.

The benefits associated with using hormonal contraception far outweigh the side effects, which are rare, in the vast majority of women who use it. 

Side effects – combined contraceptives
A very rare side effect of the combined hormonal contraceptive is associated with an increased risk of venous thromboembolism,VTE, or unwanted blood clots in the veins - better known as deep vein thrombosis (DVT).  The risk of VTE is slightly higher for pills that contain the progestogens desogestrel or gestodene than those that contain the progestogen levonorgestrel: Longer term use of the combined hormonal contraceptive has also been associated with a small increase in the risk of cervical cancer:

› Oral contraceptives and cervical cancer - 4 April 2003

For further information on the side effects of combined hormonal contraceptives refer to the patient information leaflet (PIL) that should accompany every pack of medicine.  This is also available on the electronic Medicines Compendium website. (external link)

Side effects – progestogen-only contraception
Depo-Provera is a progestogen-only contraceptive injection that causes a temporary thinning of the bones while it is being used.  In November 2004 new research in teenage users resulted in a change to the information for prescribers and users:

› Updated guidance on the use of Depo-Provera contraception - 18 November 2004

For further information on the side effects of progestogen-only pills refer to the patient information leaflet (PIL) that should accompany every pack of medicine.  This is also available on the electronic Medicines Compendium website. (external link)