The contraceptive implant is a long-term form of contraception that can provide protection against pregnancy for three years. It doesn’t protect against sexually transmitted infections (STIs), so anybody using the implant may need to also use a barrier contraception such as condoms.
How the contraceptive implant works
The question ‘how does the contraceptive implant work?’ isn’t always one that everyone knows the answer to. However, it is simple. The contraceptive implant consists of a flexible, small plastic rod that is placed under the skin of the upper arm. This will release a synthetic form of progesterone, called progestogen, into your blood for three years. An increased level of progestogen in the blood helps to prevent pregnancy in three ways:
- Preventing the release of an egg from the ovaries (also known as ovulation)
- Thickening the cervical mucus, which makes it harder for any sperm to reach the womb and fertilise an egg
- Thinning the womb lining, making it more difficult for a fertilised egg to implant itself
You can use the contraceptive implant up until menopause, but it will need to be replaced every three years. It can be removed at any time. Using local anaesthetic, a doctor or nurse will make a small cut so they can pull the implant out. Once it has been removed, you won’t be protected from pregnancy.
How is the contraceptive implant fitted?
Having the contraceptive implant put in doesn’t require surgery. You’ll be injected with a local anaesthetic to make your upper arm numb. Then the implant will be inserted into the skin - it should only take a few minutes and can feel like having an injection. No stitches will be needed, and you’ll be able to go home immediately after having it fitted.
Starting to use the contraceptive implant
No matter where you are in your menstrual cycle, you can have the implant inserted - so long as you’re not pregnant. If you have it put in during the first 5 days of your cycle, you’ll be immediately protected against pregnancy. If you have it put in on day 6 or later, you’ll need to use another type of contraceptive for 7 days, such as a condom.
You can also have the implant fitted at any time after you give birth. If it’s inserted before day 21 following birth, you’ll be protected against pregnancy straight away. For implants fitted on or after day 21, however, you should continue to use an alternative method of contraception for 7 days. The implant can be fitted immediately following an abortion or miscarriage too and it will offer protection from pregnancy from the outset.
Who can use the contraceptive implant?
The contraceptive implant is suitable for many women. However, it may not be the best choice for you if you:
- Don’t want your periods to change
- Take medicines or have a condition which may affect contraceptive implant effectiveness - speak to a pharmacist or doctor to find out if this applies to you
- Suspect you may be pregnant
- Experience bleeding after sex or in between periods that you can’t explain
- Have arterial disease or liver disease
- Have a history of strokes or heart disease
- Have or have had breast cancer
You should also inform your doctor or healthcare assistant if you are sensitive or allergic to local anaesthetic.
Women who can’t use oestrogen-based contraceptives can use the contraceptive implant. It’s also useful for women who don’t want to have to remember to use contraception such as pills or condoms as a routine or every time they have sex.
How effective is the contraceptive implant?
The contraceptive implant is more than 99% effective at preventing pregnancy. However, certain medications can interfere with it, which can reduce its effectiveness. These include:
- HIV, tuberculosis and epilepsy medications
- Some herbal remedies, for example St John’s Wort
- Certain antibiotics such as rifampicin and rifabutin
If you’re taking any of these medications in the short term, you may consider using another type of contraception alongside the implant, such as condoms. However, if you’re going to be taking the medication in question for a long period of time, it may be better to consider a different method of contraception until you stop taking the medication.
If you already have the implant and are prescribed new medications, you should always check with your doctor that the medication won’t interfere with your implant. They will suggest steps to take to ensure that you are protected against pregnancy.
Common side effects of the contraceptive implant
Contraceptive implant side effects include altered periods. In some women, this can be a positive side effect, as the implant can help to lighten heavy periods and reduce pain. However, it can also do the opposite. Additionally, the contraceptive implant may cause amenorrhoea, which is a condition where your periods stop altogether. This isn’t harmful, but it is something to consider when making your decision.
In the first few months of using the contraceptive implant, you may also experience some temporary side effects, such as nausea, headaches, mood swings and breast tenderness. You might experience acne, or have your acne get worse. Furthermore, the area where the implant was inserted may be painful or swollen at first.
Risks of using the contraceptive implant
There is a small risk that the area where the contraceptive implant was put in may get infected after the procedure. This is rare, but you should see a GP as soon as possible if you think it may have happened to you.
Medical attention should also be sought any time after you’ve had the implant inserted if:
- You think you might be pregnant
- You can’t feel the implant
- The skin where it was put in feels different or painful for a prolonged period after the procedure
- The implant feels as though it has changed in size or shape
Where to get the contraceptive implant
The contraceptive implant is free for everyone in the UK, even if you’re under the age of 16. You can get it from:
- Some GP surgeries
- Contraception clinics
- Some young people’s services
- Sexual health or genitourinary medicine (GUM) clinics
Not all doctors and practice nurses are qualified to insert or remove contraceptive implants. It’s a good idea to check beforehand that the location you choose can provide the service.