It works by stopping ovulation, thickening the mucus around the cervix, which makes it harder for sperm to get through, and making the lining of the womb thinner so that a fertilised egg cannot implant.
The implant is about 40mm long (about the size of a matchstick), and is put under the skin in your upper arm by a specially trained health professional (doctor or nurse). Once it is put in, it protects against pregnancy for three years, or until you have it taken out.
Spend a bit of time looking here and finding out more about the implant. If you can’t find what you’re looking for here, or if you have more questions, you can get in touch with Ask Brook. Ask Brook is confidential. That means we won’t tell anyone you’ve contacted us unless we think you are in really serious danger.
The implant is a long acting reversible contraception (or LARC) method. LARC methods don’t rely on you remembering to take them, but they do need a trained doctor or nurse to administer or fit them for you.
The implant is placed just under the skin, in your upper arm. A doctor or nurse will give you a local anaesthetic injection, to numb this part of your arm before they put the implant in. It should only take a few minutes, and you won't need any stitches. The area may be slightly tender for a few days, but the doctor or nurse will put a small dressing on, to protect it and help stop any bruising.
If the implant is put in during the first five days of your period, it protects you against pregnancy straight away.
If it's put in on any other day of your menstrual cycle you will not be protected against pregnancy for the first seven days, so you'll need to use another method of contraception, (like condoms) for the first seven days.
Periods may be irregular or stop altogether.
The implant is over 99% effective.