The contraceptive implant is a small flexible tube that's inserted under the skin of your upper arm. It releases the hormone progestogen to prevent pregnancy. Find out how it works and how it might affect periods and fertility.
A woman can get pregnant if a man’s sperm reaches one of her eggs (ova). Contraception tries to stop this happening by keeping the egg and sperm apart or by stopping egg production. One method of contraception is the implant.
The implant is about 40mm long and contains progestogen.
Who can insert the implant?
The implant is inserted under the skin of your upper arm by a trained professional, such as a doctor. It lasts for three years.
You can have the implant removed at any time, and your natural fertility will return very quickly. This means that once the implant is removed, you could get pregnant as easily as if you'd never had the implant.
In the UK, implants inserted after October 2010 are called Nexplanon. Implants inserted before this are called Implanon. They work in the same way, but Nexplanon is designed to reduce the risk of insertion errors, and it's visible on an X-ray or CT scan. There's no need for existing Implanon users to have their implant removed and replaced by Nexplanon ahead of its usual replacement time.
How does the implant work?
The implant stops the release of an egg from the ovary by slowly releasing progestogen into your body. It thickens the cervical mucus and thins the womb lining. This makes it harder for sperm to move through your cervix, and less likely for your womb to accept a fertilised egg.
How effective is it?
If implanted correctly, it's more than 99% effective. Fewer than one woman in 1,000 will get pregnant in one year.
Added benefits?
- It's very useful for women who know they don't want to get pregnant for a while. Once the implant is in place, you don't have to think about contraception for three years.
- It can be useful for women who can't use contraception that contains oestrogen.
- It's very useful for women who find it difficult to take a pill at the same time every day.
- It is not affected by antibiotics.
- If you have side effects, the implant can be taken out.
What else should I know about the implant?
- When it's first put in, you may feel some bruising, tenderness or swelling around the implant.
- In the first year after the implant is fitted, your periods may become irregular, lighter, heavier or longer. This usually settles down after the first year. Find out more about heavy periods and irregular periods.
- A common side effect of the implant is that your periods stop (amenorrhoea). It's not harmful, but you may want to consider this before deciding to have an implant.
- Some medicines, such as medication for HIV or epilepsy, or homeopathic remedies, such as St John's Wort, may reduce the implant's effectiveness. Ask your doctor for more details, or contact the FPA helpline on 0845 122 8690.
- If you have any problems or questions, or you want the implant removed, see your doctor or nurse.
By using condoms as well as the implant, you'll help to protect yourself against sexually transmitted infections (STIs).
Further information
When can I get pregnant?
Where can I go for sexual health advice?
When can I get contraception again after having a baby?
What infections can I catch from oral sex?
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