The contraceptive implant is a thin, flexible rod about 4cm long. It's inserted under the skin of your upper arm by a professional.
The implant stops the release of an egg from the ovary by slowly releasing progestogen into your body. Progestogen also 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.
At a glance: the implant
If implanted correctly, it's more than 99% effective. Fewer than 1 woman in 1,000 who have the implant as contraception for 3 years will get pregnant.
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 3 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.
If you have side effects or want to have a baby, the implant can be taken out.
Your natural fertility returns very quickly after removal.
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 a few months.
Your periods may stop (amenorrhoea). This isn't harmful.
Some medications can make the implant less effective. You should use extra contraception when taking these medications.
The implant does not protect against sexually transmitted infections (STIs). Use condoms as well as the implant to protect yourself against STIs.
There is no evidence to show that the implant causes weight gain.
How the implant works
The implant steadily releases the hormone progestogen into your bloodstream. Progestogen is like the natural hormone progesterone.
The continuous release of progestogen:
- stops a woman releasing an egg every month (ovulation)
- thickens the mucus from the cervix (entrance to the womb), making it difficult for sperm to pass through to the womb and reach an unfertilised egg
- makes the lining of the womb thinner so that it is unable to support a fertilised egg
The implant can be put in at any time during your menstrual cycle, as long as you and your doctor are reasonably sure you are not pregnant. In Scotland, Nexplanon is the only contraceptive implant currently in use.
Nexplanon is a small, thin, flexible tube about 4cm long. It's implanted under the skin of your upper arm by a doctor or nurse. A local anaesthetic is used to numb the area. The small wound made in your arm is closed with a dressing and does not need stitches. Nexplanon works for 3 years.
The implant can be removed at any time by a specially trained doctor or nurse. It only takes a few minutes to remove, using a local anaesthetic. As soon as the implant has been removed, you'll no longer be protected against pregnancy.
When it starts to work
If the implant is fitted during the first 5 days of your menstrual cycle, you'll be immediately protected against becoming pregnant. If it's fitted on any other day of your menstrual cycle, you will not be protected against pregnancy for up to 7 days. You should use another method during this time, such as condoms.
After giving birth
You can have the contraceptive implant fitted after you have given birth, usually after 3 weeks.
If it's fitted on or before day 21 after the birth, you'll be immediately protected against becoming pregnant.
If it's fitted after day 21, you'll need to use extra contraception, such as condoms, for the following 7 days.
It's safe to use the implant while you are breastfeeding.
After a miscarriage or abortion
The implant can be fitted immediately after a miscarriage or an abortion, and you'll be protected against pregnancy straight away.
Who can use the implant?
Most women can be fitted with the contraceptive implant. It may not be suitable if you don't want irregular bleeding, or if you have a hormone dependent cancer such as breast cancer.
Advantages and disadvantages of the implant
The main advantages of the contraceptive implant are:
- it works for 3 years
- it does not interrupt sex
- it's suitable if you can't use oestrogen-based contraception, such as the combined contraceptive pill, contraceptive patch or vaginal ring
- you don't have to remember to take a pill every day
- it's safe to use while you are breastfeeding
- your fertility should return to normal as soon as the implant is removed
- after the contraceptive implant has been inserted, you should be able to carry out normal activities
Using a contraceptive implant may have some disadvantages. You should consider these carefully before deciding if it's right for you.
Your periods may change significantly while using a contraceptive implant. Around 20% of women using the implant will have no bleeding, but almost 50% will have infrequent or prolonged bleeding. Bleeding patterns often remain irregular.
These changes are not harmful. If the bleeding is a problem, your GP may be able to give you tablets to help.
Other side effects that some women report are:
- breast tenderness
- changes in mood
- loss of sex drive
These side effects usually stop after the first few months. If you have prolonged or severe headaches or other side effects, tell your doctor.
Will other medicines affect the implant?
Some medicines can reduce the implant's effectiveness. These include:
- medication for HIV
- medication for epilepsy
- complementary remedies, such as St John's Wort
- an antibiotic called rifabutin (which can be used to treat tuberculosis)
- an antibiotic called rifampicin (which can be used to treat several conditions, including tuberculosis and meningitis)
These are called enzyme-inducing drugs. If you are using these medicines for a short while, you should use extra contraception during the course of treatment and for 28 days afterwards. The extra contraception could be condoms, or a single dose of the contraceptive injection. The implant can remain in place if you have the injection.
If you're taking enzyme-inducing drugs long term, you may prefer another method of contraception.
Always tell your doctor that you are using an implant if you are prescribed any medicines. Ask your doctor or nurse for more details about the implant and other medication.
Risks of the implant
In rare cases, the area of skin where the implant has been fitted can become infected. If this happens, the area will be cleaned and may be treated with antibiotics.
Where can you get the implant?
Most types of contraception are available for free in the UK. Contraception is free to all women and men through the NHS. Places where you can get contraception include:
- most GP practices – talk to your GP or practice nurse as not all practices fit implants
- sexual health clinics – they also offer contraceptive and STI testing services
- some young people’s services
Implants are usually removed by the service or practice where it was fitted. If not, your GP or sexual health service can advise on where implants removal is provided in your area.