An implant is a small flexible rod that is placed just under your skin in your upper arm. It releases a progestogen hormone similar to the natural progesterone that women produce in their ovaries and works for up to three years.
How effective any contraceptive is depends on how old you are, how often you have sex and whether you follow the instructions.
If 100 sexually active women don’t use any contraception, 80 to 90 will become pregnant in a year.
The implant is over 99 per cent effective. Less than one woman in every 1,000 will get pregnant over three years.
The implant is a method of long-acting reversible contraception (LARC). All LARC is very effective because while it is being used you do not have to remember to take or use contraception.
The main way it works is to stop your ovaries releasing an egg each month (ovulation). It also:
- Thickens the mucus from your cervix. This makes it difficult for sperm to move through your cervix and reach an egg.
- Makes the lining of your uterus (womb) thinner so it is less likely to accept a fertilised egg.
Only a doctor or nurse who has been trained to fit implants can insert the implant. You can go to a contraception or sexual health clinic or to the doctor or nurse at a general practice. All treatment is free and confidential (see How to get help with your sexual health).
Most women can have an implant fitted. The doctor or nurse will need to ask you about your own and your family’s medical history to make sure that the implant is suitable. You should tell them about any illnesses or operations you have had.
An implant may not be suitable for you if:
- you think you might already be pregnant
- you do not want your periods to change
- you take certain medicines.
You have now, or had in the past:
- arterial disease or history of serious heart disease or stroke
- disease of the liver
- breast cancer or breast cancer within the last five years
- unexplained vaginal bleeding (for example, bleeding between periods or after sex)
- systemic lupus erythematosus.
- It works for three years.
- You can use it if you are breastfeeding.
- Your fertility will return to normal as soon as the implant is taken out.
- It may reduce heavy, painful periods.
- Your periods may change in a way that is not acceptable to you (see below, How will an implant affect my periods?).
- You may get temporary side effects when you first start using the implant. These should stop within a few months. They include headaches, breast tenderness and mood changes.
- Some women may get acne or their acne may worsen.
- It is not suitable for women using enzyme-inducing drugs (see below, Can anything make an implant less effective?).
- It requires a small procedure to fit and remove it.
- An implant does not protect you against sexually transmitted infections, so you may need to use condoms as well.
Very rarely, soon after the implant is put in you may get an infection in your arm where it has been inserted.
Research about the risk of breast cancer and hormonal contraception is complex and contradictory. Research suggests that women who use hormonal contraception appear to have a small increase in risk of being diagnosed with breast cancer compared to women who don’t use hormonal contraception.
You can have an implant fitted at any time in your menstrual cycle if it is certain that you are not pregnant.
If the implant is put in during the first five days of your period you will be protected against pregnancy immediately.
If the implant is put in on any other day you will not be protected against pregnancy for the first seven days after it has been fitted. So you will need to use an additional method of contraception, such as condoms, during this time.
You can have an implant put in three weeks (21 days) after you have given birth. If the implant is put in on or before day 21 you will be protected against pregnancy immediately. If the implant is put in later than day 21 you will need to use an additional method of contraception for seven days.
An implant can be used safely while you are breastfeeding and will not affect your milk supply.
The implant can be put in immediately after a miscarriage or abortion. You will be protected against pregnancy immediately.
The implant, which is the size of a match stick, is placed just under your skin in the inner area of your upper arm.
A trained doctor or nurse will give you a local anaesthetic to numb the part of your arm where the implant will go, so it won’t hurt. It only takes a few minutes to put in and feels similar to having an injection. You won’t need any stitches.
After it has been fitted the doctor or nurse will check your arm to make sure that the implant is in position. You will also be shown how to feel the implant with your fingers, so you can check it is in place.
The area may be tender for a day or two and may be bruised and slightly swollen. The doctor or nurse will put a dressing on it to keep it clean and dry and to help reduce the bruising. Keep this dressing on for a few days and try not to knock the area.
Don’t worry about knocking the implant once the area has healed. It should not break or move around your arm. You will be able to do normal activities and you won't be able to see it.
You do not need to have a vaginal examination or cervical screening test to have an implant inserted.
An implant can be left in place for three years or it can be taken out sooner if you decide you want to stop using it.
A specially trained doctor or nurse must take it out. The doctor or nurse will feel your arm to locate the implant and then give you a local anaesthetic injection in the area where the implant is. They will then make a tiny cut in your skin and gently pull the implant out. They will put a dressing on the arm to keep it clean and dry and to help reduce the bruising. Keep this dressing on for a few days.
It usually only takes a few minutes to remove an implant. If the implant has been put in correctly, it should not be difficult to remove. Occasionally, an implant is difficult to feel under the skin and it may not be so easy to remove. If this happens, you may be referred to a specialist centre to have it removed with the help of an ultrasound scan.
If you want to carry on using an implant, the doctor or nurse can put a new one in at the same time. You will continue to be protected against pregnancy.
Some medicines may make an implant less effective. These include some of the medicines used to treat HIV, epilepsy and tuberculosis, and the complementary medicine St John’s Wort. These are called enzyme-inducing drugs. If you are using these medicines it will be recommended that you use additional contraception, such as condoms, or that you change your method of contraception.
Always tell your doctor or nurse that you are using an implant if you are prescribed any medicines.
The implant is not affected by common antibiotics, diarrhoea or vomiting.
It is important to have your implant changed at the right time. If it is not you will not be protected against pregnancy. If you have sex without using another method of contraception and don’t wish to become pregnant you may want to consider using emergency contraception.
Your periods will probably change.
- Most women will have irregular periods.
- In some women periods will stop completely.
- Some women will have periods that last longer.
These changes may be a nuisance but they are not harmful. If you do have prolonged bleeding the doctor or nurse may be able to give you some additional hormone or medicine that can help control the bleeding. They may also check that the bleeding is not due to other causes, such as an infection.
If you want to stop using the implant you need to go back to the doctor or nurse and ask them to take it out. Your periods and fertility will return to normal and it is possible to get pregnant before you have your first period. If you don’t wish to become pregnant then you should use another method of contraception from the day that your implant is removed.
If you want to try for a baby, start pre-pregnancy care such as taking folic acid and stopping smoking. You can ask your doctor or nurse for further advice.
No. It is not necessary to stop using the implant if you are having an operation. However, it is always recommended that you tell the doctor that you are using the implant.
If you have no medical problems you can continue to use the implant until you reach the menopause. Each implant will last for three years and will then need to be replaced.
The implant is a highly effective method of contraception. If you have not taken any medicine that might make the implant less effective and have had the implant changed on time it is very unlikely that you will become pregnant.
If you think that you might be pregnant then do a pregnancy test or speak to your doctor or nurse as soon as possible. Using the implant will not affect a pregnancy test. If you do get pregnant while you are using the implant there is no evidence that it will harm the baby. The implant should be removed if you want to continue with the pregnancy.
You only need to go to the clinic or your general practice if you have any problems with your implant or when it needs to be replaced. If you have any problems, questions or want the implant removed you should contact your doctor or nurse.
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This website can only give you general information about contraception. The information is based on evidence-guided research from the World Health Organization and The Faculty of Sexual and Reproductive Healthcare of the Royal College of Obstetricians and Gynaecologists. All methods of contraception come with a Patient Information Leaflet which provides detailed information about the method.
Remember – contact your doctor, practice nurse or a contraception clinic if you are worried or unsure about anything.
INFORMATION LAST UPDATED JULY 2014. NEXT UPDATE DUE 2015.