Arm implant birth control explained

How does the contraceptive implant work?

The contraceptive implant, sometimes also known by the brand names Nexplanon or Implanon, is a small plastic rod. It’s small and thin, about the size of a matchstick, and is inserted under the skin in your upper arm (usually your non-dominant arm) by a healthcare provider.

Once it’s inserted, you’ll be able to feel it under your skin, but you won’t be able to see it. It can be left in place for up to five years (usually three years for Nexplanon and five years for Implanon), and during this period you don’t need to do anything else when it comes to preventing pregnancy. 

The implant releases the hormone progesterone into your bloodstream to prevent pregnancy. This works as:

• Progesterone thickens cervical mucus, which prevents sperm from reaching the egg cell
• The hormone also stops ovulation, meaning there aren’t any eggs to fertilize (if sperm did manage to make it through)

How effective is the contraceptive implant?

If you want to prevent pregnancy, contraceptive implants are one of the most effective forms of birth control out there. With perfect use, the implant is more than 99% effective, meaning that fewer than 1 in 100 people who use the contraceptive implant get pregnant every year.

We usually talk about ‘perfect use’ and ‘typical use’ when discussing the effectiveness of different types of birth control. Perfect use means how effective a particular method is when used as intended, and typical use refers to the effectiveness when used as most people do. There is often a significant difference between the two, which is down to user error (forgetting to take a pill, for example).

However, because you don’t need to do anything else once the implant is inserted, there’s no way you can make a mistake with it. You can simply have it inserted, then forget about it, knowing that you’ll be protected against pregnancy for several years - although if you do decide you want to try for a baby at any stage, you can have it removed by your healthcare provider. 

For some it’s possible to get pregnant straight away after getting an implant removed. For others it can take a bit longer as hormone levels may take time to re-adjust. If you’re looking to get pregnant in the near future, consider switching to a non-hormonal birth control method. 

Advantages and disadvantages of contraceptive implants

As with any birth control method, there are both advantages and disadvantages to the birth control implant, and it’s important to be aware of them when deciding if it’s the right contraceptive option for you.

Advantages of the birth control implant

As already mentioned, the birth control implant is one of the most effective forms of birth control, and it’s also super convenient as there’s no way you can get it wrong. Once it’s been inserted, there’s no daily maintenance - you don’t need to worry about taking it every day or going to the pharmacy for a refill.

Because it’s a long-lasting form of birth control, it also means that you don’t need to interrupt sex to use it.

Contraceptive implants don’t contain estrogen, so it may be a preferable option for those who can’t take this hormone. Hormonal birth control containing estrogen is not recommended for people who are:

• Over 35 and a smoker
• Obese
• Prone to certain types of migraines
• Using certain medications
• Affected by poor circulation

Some others prefer not to take estrogen because they experience unwanted side effects such as:

• Mood swings
• Irregular bleeding
• Headaches
• Low sex drive
• Nausea
• Weight gain

That’s not to say that you won’t experience any side effects when using the contraceptive implant, but these may be decreased. We’ll explain some of the side effects you might experience below.

Many do find that their periods become lighter when using the implant, or even stop completely. It may also reduce period cramps and pains.

You can use the contraceptive implant if you’re breastfeeding, and it can be used immediately after having a baby.

Disadvantages of the contraceptive implant

Some women experience negative side effects when using the implant, including:

• Headaches
• Breast tenderness
• Bruising at the insertion site
• Weight gain
• Mood swings
• Acne
• Spotting 

The most common side effect is spotting or irregular bleeding. Most women will experience spotting after getting the implant, most commonly in the first 6-12 months after insertion. There are several ways your menstrual cycle can be affected when you have the implant. You may experience longer or shorter periods, have no period at all, spotting between periods, or the number of days between your periods may vary. 

These symptoms often subside after the first few months, but you should speak to your healthcare provider if you have any concerns.

One of the major drawbacks of the contraceptive implant is that it doesn’t protect against sexually transmitted infections. You may therefore also want to use a barrier method of contraception like condoms when you have sex.

Is the implant suitable for everyone?

Contraceptive implants are an option for most women, but there are a few people who may need to avoid using them. It’s important to discuss your full list of options and your medical history with your doctor before changing contraceptive method to find out if it’s right for you.

Some medicines can make the implant less effective. These include:

• Medicines used to treat HIV, TB and epilepsy
• Some antibiotics like rifampicin and rifabutin
• Herbal remedies like St John’s Wort (sometimes used to treat low mood)

You should let your healthcare provider know if you’re taking any of these medicines. You may want to use condoms as an additional birth control method while you have the implant inserted, or you may decide to use another contraceptive method entirely.

What to expect when you get the implant

It’s a small procedure to get the implant inserted, and it should take just a few minutes at your healthcare provider’s office.

You can get the implant inserted at any time as long as you’re not pregnant, although you may need to use a backup method of contraception depending on when in your menstrual cycle you get it inserted. 

If you have the implant inserted during the first five days of your menstrual cycle, then it’ll prevent pregnancy immediately. If you have it fitted at any other time during your menstrual cycle, then you should use a backup method of contraception, like condoms, for seven days.

When you go for the procedure, you’ll be asked to lie on your back with your arm bent at the elbow, up towards your head. Your healthcare provider will then find the right location to insert the implant, a small flexible plastic rod. It usually goes in between the bicep and tricep muscles on the inner side of your upper arm.

They’ll give you a local anesthetic to numb the area, before inserting the implant. It shouldn’t cause you much pain - it should just feel like you’re getting an injection - and will only take a minute or so.

Once it’s inserted, your healthcare provider will feel your arm to make sure it’s in place, and they’ll get you to feel it as well. They’ll then cover the insertion site with a bandage. You may experience some bruising and pain at the insertion site over the next couple of days.

Removing the implant

Getting the implant removed also only takes a few minutes. Again, you’ll be given a local anesthetic to numb the area, and then your healthcare provider will make a small cut in your upper arm before gently pulling the implant out. They will then close the cut and cover it with a bandage.

You can get a new implant inserted at the same time as getting your previous implant removed. If you choose not to do this and don’t want to get pregnant, you’ll need to start using another form of birth control straight away, as you’ll no longer be protected against pregnancy.

Finding the right birth control method for you

Birth control is a very individual choice, and the implant may or may not be the right method for you. There are lots of different factors to consider when it comes to choosing contraception, from its effectiveness, to side effects, to family planning and lifestyle choice - but the most important thing is that we all have access to a multitude of birth control methods, and have the information we need to make an informed choice.

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