A subdermal implant is a device placed just under the skin. These devices are often small, sometimes the size of a matchstick, and are inserted in the subcutaneous layer of tissue. The body’s skin then heals over the implant. This method of delivery allows for various long-term applications without daily action from the user.
Common Applications of Subdermal Implants
The most widespread use of subdermal implants is for long-acting reversible contraception. These implants, such as the brand Nexplanon, are thin, flexible plastic rods inserted under the skin of the upper arm. They work by steadily releasing a progestin hormone called etonogestrel into the bloodstream. This hormone prevents pregnancy by stopping the release of an egg from the ovary, thickening cervical mucus to prevent sperm from reaching an egg, and thinning the uterine lining.
Contraceptive implants are highly effective and are licensed for use for up to three years, though some evidence suggests they may remain effective for longer. Beyond contraception, another application of subdermal implants is bio-hacking. Individuals may have small RFID (Radio-Frequency Identification) or NFC (Near Field Communication) chips implanted. These electronic chips can be programmed to perform tasks like unlocking doors, storing data, or making payments with a wave of the hand.
A growing application is in the field of medical monitoring. Continuous glucose monitors (CGMs) are a form of subdermal device used by individuals with diabetes. These systems use a tiny sensor inserted under the skin, typically on the abdomen or arm, to automatically track blood glucose levels throughout the day and night. The sensor measures glucose in the fluid between cells and sends the data wirelessly to a monitor or smartphone, providing real-time readings and alerts.
The Insertion and Removal Procedure
The process of inserting a subdermal implant is a minor and quick procedure performed by a trained healthcare professional in a clinical setting. It begins with the administration of a local anesthetic to numb a small area on the inside of the upper arm. Once the area is numb, the provider makes a small incision or uses a special applicator tool to place the implant just beneath the skin’s surface.
Once the implant is in place, the applicator is removed, and the insertion site is cleaned. A small adhesive bandage is applied over the site, often followed by a pressure bandage to help minimize bruising and swelling. Patients are advised to keep the pressure bandage on for 24 hours and the smaller bandage for three to five days, while also keeping the area dry.
Removing the implant involves a very similar in-office procedure. A healthcare provider will numb the area with a local anesthetic before making a small incision near the end of the implant. The provider then gently pushes the implant toward the incision until the tip is visible and can be grasped with forceps and pulled out. If the implant is being replaced, the new device can often be inserted through the same incision.
Health and Safety Considerations
For contraceptive implants, the most common side effect relates to changes in menstrual bleeding patterns. Many users experience irregular bleeding, spotting between periods, or a complete cessation of their period. While not medically dangerous, unpredictable bleeding is one of the main reasons some users choose to have the implant removed. Other potential side effects include headaches, mood changes, weight gain, acne, and breast tenderness.
The insertion and removal procedures carry their own set of risks, though they are uncommon. The primary risk is infection at the insertion site. There is also a possibility of minor pain, scarring, or bruising at the site. In rare cases, the implant may be inserted too deeply, making removal more difficult, or it may migrate slightly from its original position.
Hormonal implants are not suitable for everyone. They are not recommended for individuals with a history of serious blood clots, liver disease, certain types of cancer (such as breast cancer), or unexplained vaginal bleeding. A thorough medical history is reviewed by a clinician to ensure the implant is a safe option for the patient.