When most of us think about a "birth control implant," we think about the kind that gets inserted inside your uterus, aka an intrauterine device or IUD. But the IUD isn't the only kind of birth control implant — there's also one that can be inserted under the skin of your arm. While the location of a hormonal IUD seems straightforward (it goes inside your uterus, after all), an implant in your arm seems a little more complicated. So, here's how it works.
The birth control implant (Nexplanon is the name of the drug, or "etonogestrel implant") is a really small rod that's inserted underneath the skin of your upper arm, and releases a low dose of the hormone progestin into your bloodstream, according to MedlinePlus. Progestin thickens your cervical mucus, which keeps sperm from entering the uterus, thins your uterine lining, and prevents ovulation, according to the American College of Obstetrics and Gynecology (ACOG). Once it's in your arm, it works for up to three years, then you have to have it replaced. The birth control implant is another "set-it-and-forget" option like the IUD, which is what makes it appealing to some people.
So, why get an arm implant when you could just take a pill or get an IUD? The birth control implant tends to be a good option for people who can't be on birth control that contains estrogen (like women who get migraines with auras, for example), according to Planned Parenthood. Progestin-only pills are often called "the mini-pill," because they contain such a low dose of the hormone, and because they have to be taken at exactly the same time every single day in order to be effective, according to the Mayo Clinic. But with the implant, you don't have to stress about taking a pill on time everyday, because it's always in your arm. In fact, some people prefer having the implant because it's discreetly hidden underneath their skin.
Compared to the lore surrounding IUD insertion, the birth control implant procedure is relatively chill. Most people get it inserted during the first days of their period, although your doctor may have a different suggestion. Your doctor will numb the area on your arm, and use a fancy applicator to shoot it under your skin, according to the ACOG. It takes about a minute, and doesn't really hurt.
After the device has been inserted, it's normal to experience some bruising or pain around the spot where it was inserted, according to the Nexplanon website. Sometimes, scar tissue can build up around the implant, which makes it harder to remove and re-insert. And in rare cases, the implant can break or even fall out. As far as other side effects are concerned, people usually complain about changes in their period, like spotting or longer periods, but that's pretty standard for a progestin-only pill. Some people also report headaches, inflammation of the vagina, weight gain, acne, breast pain, and mood swings, but those tend to be less common.
Overall, the birth control implant is very effective, and studies have shown that it's as good as an IUD. If you're curious, ask your Ob/Gyn if they think it'd be a smart choice for you. It can be a challenge to find a birth control method that works for you and your lifestyle — so it's good to know that there are options for those of us who want a long-term birth control method.