Nexplanon is safe to have during an MRI. The implant is made entirely of plastic and contains no metallic parts, so it won’t interact with the magnetic field, heat up, or move during a scan. The FDA’s own prescribing information lists MRI as one of the acceptable imaging methods for patients with the implant.
Why Nexplanon Is MRI Safe
The safety comes down to what the implant is made of. Nexplanon’s core is an ethylene vinyl acetate (EVA) copolymer, a type of flexible plastic. Inside that plastic core sits the hormone it releases (etonogestrel), plus barium sulfate, the ingredient that makes it visible on X-rays. The outer shell is also EVA copolymer. None of these materials are ferromagnetic, meaning none of them are attracted to magnets or generate heat in a magnetic field.
This is a meaningful distinction from some other implanted devices. Certain metal-containing IUDs have only been tested up to 1.5 Tesla MRI machines and may not be cleared for the stronger 3T scanners increasingly used in hospitals. Nexplanon doesn’t have this limitation because there’s simply no metal in the device to worry about.
What Happens to the Implant During a Scan
Nothing, from a safety standpoint. You won’t feel any warming, pulling, or vibration at the implant site. The rod stays exactly where it is in your arm.
Visually, the implant does show up on MRI images, though it looks quite small. On cross-sectional scans, it appears as a tiny dark dot about 2 mm across. It shows up dark on every type of MRI sequence because the plastic material doesn’t contain water or the kind of molecules that MRI machines use to generate a signal. This dark appearance is consistent and predictable, and it doesn’t create the kind of large signal distortions (called artifacts) that metal implants produce. In practical terms, it won’t interfere with the quality of your scan unless the radiologist is specifically trying to image the tissue right next to the implant itself.
Do You Need to Tell the MRI Team?
Yes, always mention it. Before any MRI, you’ll fill out a screening form asking about implanted devices. Listing Nexplanon is straightforward since the implant is a known non-issue in radiology departments. Unlike patients with certain cardiac devices or metal implants who may need special protocols or clearance, having Nexplanon in your arm won’t delay or change your scan.
The FDA prescribing label does not require patients to carry a specific MRI safety card for Nexplanon, and there’s no formal pre-scan clearance process needed. Your honesty on the screening form is enough for the technologist to proceed confidently.
MRI as a Tool to Find the Implant
Interestingly, MRI isn’t just safe with Nexplanon, it’s actually used as a diagnostic tool when the implant can’t be felt or found through other methods. If an implant has migrated deeper into the arm or can’t be located by physical exam, imaging is the next step. X-ray and ultrasound are tried first since they’re faster and cheaper, but when those don’t work, MRI can pinpoint the implant’s exact location relative to nerves and blood vessels.
Radiologists use a few tricks to make the implant easier to spot on MRI. They avoid a technique called fat suppression, which can hide the implant within the surrounding tissue. If the rod has migrated close to major nerves or blood vessels, contrast dye can be injected to help distinguish the implant from nearby structures and plan safe removal. This kind of detailed mapping is especially useful before surgical retrieval of a deeply embedded implant.
Bottom Line on Safety
Nexplanon contains zero metal. It’s made of plastic with a hormone core and a small amount of barium sulfate for X-ray visibility. It won’t heat, move, or malfunction in any MRI machine, regardless of the field strength. If you need an MRI for any reason, the implant in your arm is not an obstacle.