How to choose the right contraception

What it is

A hormonal skin patch that's worn for one week at a time, and changed on the same day of the week, for three consecutive weeks. The fourth week, during which a withdrawal bleed occurs, is 'patch-free'. It can be worn on one of four body areas - the buttocks, abdomen, upper torso (excluding the breasts) or upper outer arm.

How it works

The contraceptive patch delivers a continuous flow of hormones (norelgestromin plus ethinyl estradiol) through the skin into the bloodstream. It prevents pregnancy by suppressing ovulation, like the combined pill (see entry). The hormones in the patch also thicken the cervical mucus, making it more difficult for sperm to enter the uterus. When used correctly, it's as effective in preventing pregnancy as combined oral contraceptives (failure rate less than 1%).

Pros

• Stays in place, even when exercising, swimming or bathing, and in humid conditions.
  
• Available in the UK on prescription from GPs and family planning clinics.
  
• Slim enough to be worn discreetly underneath clothing.
  
• Only has to be remembered once a week, rather than once a day.

Cons

• Some women forget to change the patch weekly.
  
• It may not be as effective in women who weigh 90kgs or more.
  
• A skin reaction may occur at the site of the patch, but this leads to discontinuation in less than 2% of users.