How it works
The rod slowly releases a progestogen hormone (etonogestrel) into the bloodstream. This mainly stops the ovaries from releasing an egg each month. It also thickens cervical mucus, which makes it harder for sperm to reach an egg.
People who want highly effective, long-lasting contraception without daily effort, including those who cannot take estrogen.
How effective is it?
Typical use
Over 99%
In real life fewer than 1 in 100 people get pregnant in a year.
Perfect use
Over 99%
About 0.1 in 100 when used exactly as directed every time.
See how it ranks against every method in the effectiveness chart.
How to use it
Book an appointment with a doctor, nurse, or sexual health or family planning clinic; a trained clinician fits it.
The arm is numbed with local anesthetic and the rod is placed just under the skin of the inner upper arm; it takes a few minutes and needs no stitches.
Depending on when in your cycle it is fitted, it can work straight away or you may need condoms or another method for the first 7 days; your clinician will tell you which applies.
You should be able to feel the rod under your skin; check it from time to time and get it looked at if you cannot feel it or it seems to have changed shape.
Have it removed or replaced by a trained clinician when it is due (3 years on the US label, up to 5 years in UK guidance), or any time you want to stop.
Pros and cons
Advantages
- One of the most effective reversible methods, with no need to remember anything day to day.
- Lasts for several years from a single fitting.
- Contains no estrogen, so it is an option for many people who cannot use combined methods.
- Can be used while breastfeeding.
- Fertility returns quickly once it is taken out.
- Periods may become lighter or stop, and painful periods may improve for some users.
Disadvantages
- Does not protect against sexually transmitted infections (STIs); use condoms as well for that.
- Bleeding changes are common and hard to predict, and irregular or prolonged bleeding is the most common reason people have it removed.
- Needs a trained clinician to fit and remove it, which involves a small procedure under local anesthetic.
- Some medicines, such as certain epilepsy, HIV, and tuberculosis drugs and St John's wort, can make it less effective.
Effect on periods: Bleeding often becomes irregular or unpredictable; some people stop bleeding altogether.
Possible side effects
- Irregular, infrequent, frequent, or prolonged bleeding or spotting
- Headaches
- Breast tenderness
- Acne (it may get better or worse)
- Mood changes
- Bruising, soreness, or swelling in the arm for a few days after fitting
Who it may not suit
A clinician checks your medical history before you start. This list is not complete.
May not be suitable if
- You have, or have had, breast cancer.
- You have serious liver disease or a liver tumor.
- You have unexplained vaginal bleeding that has not been checked, for example between periods or after sex.
- You take medicines that interact with it, such as some epilepsy, HIV, or tuberculosis treatments.
- You have had a stroke or heart disease; a clinician will weigh up whether it suits you.
Get medical help if
- You cannot feel the implant under your skin, or it seems to have moved or bent.
- The skin over the implant becomes red, hot, swollen, or painful, or there is discharge, which may mean infection.
- You have very heavy or long-lasting bleeding that worries you.
- You think you might be pregnant.
Frequently asked questions
How long does the contraceptive implant last?
In the US the implant is licensed for 3 years. UK guidance (NHS and FSRH) now says it works for 5 years, based on newer evidence. Ask your clinician which applies to you and when to have it replaced.
Does the implant cause weight gain?
Some people report weight changes, but studies have not shown that the implant clearly causes weight gain. If you notice changes that bother you, talk to a clinician.
Will the implant stop my periods?
It might. Some people stop bleeding, others bleed less often, and some have frequent or longer bleeding. The pattern in the first few months can change, and a clinician can sometimes suggest treatment if bleeding is a problem.
Does it hurt to have the implant put in or taken out?
The area is numbed with local anesthetic first, so most people feel only the injection of the numbing medicine and some pressure. Bruising and soreness for a few days afterward are common.
How soon can I get pregnant after the implant is removed?
Your fertility returns quickly, usually within days to weeks. Use another method straight away if you do not want to get pregnant.
Sources
Reviewed 1 November 2026. We link to the guidance itself so you can check it.