Nexplanon is a tiny, flexible plastic rod about the size of a matchstick that a doctor inserts just under the skin of your upper arm. It prevents pregnancy by steadily releasing a synthetic hormone called etonogestrel into your body for up to three years. This hormone works in three main ways: it stops your ovaries from releasing an egg, it thickens the cervical mucus to block sperm, and it thins the lining of your uterus. Because it is one of the most effective birth control methods available, understanding exactly how it works helps you decide if it fits your life.
How Does Nexplanon Work To Prevent Pregnancy?
Nexplanon works primarily by stopping ovulation. Ovulation is the process where your ovary releases an egg each month. The progestin hormone in Nexplanon sends a signal to your brain to stop producing the hormones that trigger this release. Without an egg, there is nothing for sperm to fertilize, so pregnancy cannot begin.
It also creates a second line of defense. The hormone thickens the mucus around your cervix, the opening to your uterus. This thicker mucus acts like a physical barrier that makes it very difficult for sperm to swim through and reach any egg that might have been released.
The third effect involves the lining of your uterus, called the endometrium. Nexplanon makes this lining thinner. Even in the rare case that an egg is released and fertilized, the thin lining makes it unlikely that the fertilized egg could implant and grow. These three actions together make the implant more than 99% effective at preventing pregnancy.
How Is The Implant Inserted And Removed?
Insertion is a quick office procedure. A healthcare provider numbs a small area on the inside of your upper arm with a local anesthetic. They then use a special applicator to place the rod just beneath the skin. The entire process usually takes less than a minute after the numbing medicine takes effect. You can feel the rod if you press on the area, but you should not be able to see it.
Removal is equally straightforward. The provider numbs the area again, makes a tiny incision, and gently pulls the rod out. A new implant can be inserted immediately through the same incision if you want to continue using this method. You should never try to remove the implant yourself. The rod can become embedded in deeper tissue, which makes professional removal essential.
What Side Effects Should You Expect?
The most common side effect is a change in your bleeding pattern. This is not a sign that the implant is failing; it is a normal response to the hormone. Some women have no periods at all. Others have irregular spotting or bleeding that comes and goes unpredictably. Studies show that about one in three women using the implant will have no bleeding after the first year. For many, the unpredictable bleeding is the main reason they choose to stop using it.
Other side effects can include headaches, breast tenderness, acne, weight gain, or mood changes. These are similar to side effects seen with other progestin-only birth control methods. Most side effects are mild and often improve after the first few months. If side effects are severe or do not go away, talk to your doctor about whether this method is right for you.
Serious complications are rare but possible. The main risk is infection at the insertion site, which happens in less than 1% of insertions. In very rare cases, the implant can move within the arm or travel to a blood vessel, but this is extremely uncommon. If you cannot feel the implant after insertion, contact your doctor right away to confirm it is in the right place.
When Does Nexplanon Start Protecting You?
Timing matters for how quickly you are protected. If the implant is inserted during the first five days of your menstrual cycle, you are protected from pregnancy immediately. Day one is the first day of your period.
If you get the implant at any other time in your cycle, you need to use a backup method like condoms for the next seven days. This applies unless you are switching from another highly effective method like an IUD or the pill and have been using it consistently. Your doctor will give you specific instructions based on your situation.
How Does Nexplanon Compare To Other Birth Control?
Nexplanon is one of the most effective reversible birth control options available. Its failure rate is less than 1%, which means fewer than 1 in 100 women will become pregnant during the first year of typical use. This puts it in the same effectiveness category as intrauterine devices (IUDs) and permanent sterilization.
Unlike the pill, there is no daily routine to remember. Once it is in, you do not have to think about it for three years. Unlike the Depo-Provera shot, you do not need to return to the clinic every few months for another dose. Compared to condoms, it requires no action at the time of sex and is not affected by user error.
The main trade-off is the bleeding changes and the fact that you need a healthcare provider to insert and remove it. Some women prefer an IUD because it does not contain the same hormone pattern, but both are excellent options. Your choice depends on your medical history, your preferences, and how your body reacts to progestin.
Who Should Not Use Nexplanon?
Not everyone is a candidate for the implant. You should not use Nexplanon if you have a history of blood clots in your legs or lungs, liver disease, or unexplained vaginal bleeding. Women who have had breast cancer or suspect they might have it should also avoid this method because progestin can affect hormone-sensitive cancers.
Some medications can make Nexplanon less effective. Certain seizure medications, the herbal supplement St. John’s Wort, and some HIV treatments can speed up how quickly your body breaks down the hormone. Tell your doctor about every medication and supplement you take before getting the implant. If you start a new medication while using Nexplanon, ask your pharmacist whether it interacts with hormonal birth control.
Does It Affect Your Fertility Long Term?
No. Nexplanon does not permanently affect your fertility. Once the implant is removed, your hormone levels return to normal quickly. Most women ovulate within a few weeks after removal. Studies indicate that pregnancy rates after removal are similar to those of women who have never used hormonal birth control.
There is no delay in trying to conceive after removal. You can attempt pregnancy immediately in your next cycle. The only reason you might not get pregnant right away is the same reason any woman might not — age, other health conditions, or timing of intercourse.
Frequently Asked Questions
Can Nexplanon fail while I am using it?
Yes, but it is extremely rare, with fewer than 1 in 100 women becoming pregnant in a year of use. Most failures happen because of drug interactions or because the implant was not inserted correctly.
Will I still have periods with Nexplanon?
Most women have changes to their periods, but the pattern varies widely. You may have no bleeding, irregular spotting, or heavier bleeding, and any of these patterns is considered normal.
How long does Nexplanon last before I need a new one?
Nexplanon is approved for up to three years of continuous use. After three years, it must be removed and replaced to maintain full effectiveness.
Can I get pregnant right after Nexplanon is removed?
Yes, fertility returns quickly after removal, often within a few weeks. There is no waiting period required before trying to conceive.
