What you need to know about the implant

The contraceptive implant is a flexible rod about the size of a matchstick. It sits under the skin of your upper arm. It slowly releases a copy of the hormone progesterone.

It stops ovulation in most people, thickens the cervical mucus and thins the womb lining. It’s very effective for 3 years. The main side effect is that it changes bleeding patterns in 75% of people.

The contraceptive implant:

  • is highly effective – it’s one of the most effective methods to prevent pregnancy

  • is a long-term method that lasts for 3 years

  • is reversible, so when it’s removed, your fertility goes back to what’s normal for you 

  • needs fitting by someone with specialist training

  • does not need to be remembered daily, or when you’re having sex

The implant is one of the most effective methods of contraception. It’s very safe with very few health risks, and those who are happy with this method often use it for a long time, just replacing their implant every 3 years.

So if you need very effective, long-term contraception that you do not need to think about, then this could be a good method for you. However, some people have a lot of problems with irregular bleeding, so if a regular period is important to you then this is not a good method for you.

Dr Paula Baraitser. Medical Director, SH:24

Likelihood of getting pregnant over 1 year

The implant is over 99% effective. This means fewer than 1 out of 100 people using the implant will get pregnant in one year.

The implant is a good option if you...

  • want to use hormonal contraception and do not want the risks of a combined hormone method

  • want a contraceptive that you can get fitted and then forget about 

  • want a long-lasting method of contraception

  • want to try a method that may help reduce the frequency and heaviness of your periods – about half of implant users will have less bleeding than they usually do

  • want to reduce symptoms of PMS

  • can’t take the combined pill because you get migraines with aura or you smoke and are over 35 years old

It’s not recommended for people who have…

  • current, or past history of, breast cancer – read more about health risks of the implant

  • irregular bleeding, unless you’ve already investigated the treatable causes of it

  • reduced liver function, because you need your liver to break down the hormones in the implant

  • a tendency to get scars that are larger and raised above the skin, called keloid scars, as the implant needs to be inserted through a small cut

The main side effect is irregular bleeding

The main side effect of the contraceptive implant is irregular bleeding. You may have:

  • frequent irregular bleeding

  • regular periods

  • infrequent irregular bleeding

  • no bleeding at all

It’s difficult to predict how your bleeding pattern might change, as it’s different for everyone. Once you’ve had the implant for 3 months, though, the pattern of bleeding you’ve settled into is likely to stay similar for the next 3 years.

Irregular bleeding is one of the main reasons people change to a different method of contraception. 

Read about the health benefits, risks and side effects of the implant.

Can you see the implant?

You may be able to see your implant, and you should be able to feel it.

I don't actively feel it, but sometimes if my arm is in a certain position I can see it and if my arm brushes up against something I can feel it. It doesn’t hurt, I’m used to it now.

Everything you wanted to know about sexual health and wellbeing - your questions answered by our expert team.