The contraceptive implant

Do you want a contraceptive method that frees you from having to take a pill every day? Then perhaps the long-term contraceptive implant is the answer. This fpa factsheet explains how it works.

What is it?

The implant is a small, flexible tube about the size of a hairgrip. It's inserted under the skin in the inner upper arm. It slowly releases the hormone progestogen and works for three years. It's a long-acting reversible method of contraception. There is only one implant in the UK, called Implanon.

How does the implant work?

The main way the implant works is by stopping the ovaries from releasing an egg each month (ovulation). It also:

Thickens the mucus in the cervix, making it difficult for sperm to reach an egg
Makes the lining of the womb thinner so it's less likely to accept a fertilised egg

How reliable is it?

It's more than 99 per cent effective. This means that using this method, fewer than one woman in 100 will get pregnant in a year. All long-acting reversible methods of contraception are very effective because while they're being used you don't have to remember to take or use contraception.

Myth: The implant will move around your body
Fact: Not true - once fitted in the arm, just under the skin, it does not move
Myth: It's less effective if you weigh more than 70kg
Fact:Not true - it's effective whatever weight you are

How is it used?

The implant can be inserted up to and including the fifth day of a period. If fitted at this time it's effective straight away. If it's fitted at any other time, additional contraception has to be used for seven days. Once it's in place there's nothing to remember until it needs to be changed or you want it removed.

Advantages:

Very effective
Doesn’t interrupt sex
Works for three years
Can be used by women who cannot use estrogens or who are breastfeeding
Your normal fertility returns as soon as it's removed
May give you some protection against cancer of the womb
Offers some protection against pelvic inflammatory disease
May reduce heavy, painful periods

Disadvantages:

Periods may become irregular, longer or stop
Acne may occur
Some women report mood changes and breast tenderness
Requires a small procedure to fit and remove it

Can anyone use one?

Most women who want to use an implant can have one fitted. But it may be unsuitable if you:

Think you might already be pregnant
Do not want your periods to change
Take certain medicines - always check
Have active liver disease
Have breast cancer now or within the past five years
Have thrombosis, heart or circulatory disease
Have migraines with aura

Other things to consider

Once you've had the implant fitted, you can forget about it.

You don't need a cervical screening test or an internal examination to have the implant. The implant does not protect you against sexually transmitted infections.