Last reviewed 2026-04-20 · How we verify

Nexplanon (ETONOGESTREL)

Nexplanon (ETONOGESTREL) is a progestin-based contraceptive implant developed by Organon, a subsidiary of Merck. It works by targeting sex hormone-binding globulin, a protein that binds to sex hormones, thereby preventing ovulation. Nexplanon is FDA-approved for contraception and has a half-life of 25 hours with 76% bioavailability. It is a patented product with no generic manufacturers available. Key safety considerations include potential side effects such as irregular menstrual bleeding and mood changes.

At a glance

Approved indications

• Contraception

Boxed warnings

• WARNING: CIGARETTE SMOKING AND SERIOUS CARDIOVASCULAR EVENTS Cigarette smoking increases the risk of serious cardiovascular events from combination hormonal contraceptive (CHC) use. This risk increases with age, particularly in women over 35 years of age, and with the number of cigarettes smoked. For this reason, CHCs, including Etonogestrel and ethinyl estradiol vaginal ring, should not be used by women who are over 35 years of age and smoke. [ see Contraindications ( 4 )] WARNING: CIGARETTE SMOKING AND SERIOUS CARDIOVASCULAR EVENTS See full prescribing information for complete boxed warning. Women over 35 years old who smoke should not use Etonogestrel and ethinyl estradiol vaginal ring ( 4 ) Cigarette smoking increases the risk of serious cardiovascular events from combination hormonal contraceptive (CHC) use. ( 4 ) BOXED WARNING What is the most important information I should know about Etonogestrel and ethinyl estradiol vaginal ring? Do not use Etonogestrel and ethinyl estradiol vaginal ring if you smoke cigarettes and are over 35 years old. Smoking increases your risk of serious cardiovascular side effects (heart and blood vessel problems) from combination hormonal contraceptives (CHCs), including death from heart attack, blood clots or stroke. This risk increases with age and the number of cigarettes you smoke.

Common side effects

• vaginitis
• headache (including migraine)
• mood changes (e.g., depression, mood swings, mood altered, depressed mood, affect lability)
• device-related events (e.g., expulsion/discomfort/foreign body sensation)
• nausea/vomiting
• vaginal discharge
• increased weight
• vaginal discomfort
• breast pain/discomfort/tenderness
• dysmenorrhea
• abdominal pain
• acne

Drug interactions

• Phenytoin, Barbiturates, Carbamazepine, Bosentan, Felbamate, Griseofulvin, Oxcarbazepine, Rifampicin, Topiramate, Rifabutin, Rufinamide, Aprepitant, St. John's Wort
• Oral Amoxicillin, Doxycycline
• Atorvastatin
• Ascorbic Acid, Acetaminophen
• Itraconazole, Voriconazole, Fluconazole, Grapefruit Juice, Ketoconazole
• Vaginal Miconazole Nitrate

Key clinical trials

• A Study to Assess Contraceptive Efficacy and Safety of Etonogestrel (ENG) Implant Beyond 3 Years of Use (MK-8415-060) (PHASE3)
• Long Term Evaluation of Scapular-inserted Contraceptive Implants (PHASE2)
• Vapocoolant Spray to Reduce Pain With Nexplanon Insertion (NA)
• Does Vaginal Delivery of Combined Hormonal Contraception Affect the Risk of Metabolic Syndrome in Overweight/Obese Women With PCOS (PHASE4)
• Pharmacokinetic Study of Antiretroviral Drugs and Related Drugs During and After Pregnancy
• Breastfeeding Etonogestrel Implant Study (PHASE4)
• Failed Endometrial Ablation Treatment With Implantable Progesterone (FEAT) Study (PHASE2)
• Body Composition and Sport Performance Among Young Female Soccer Players Using Subdermic Etonogestrel (EARLY_PHASE1)

Patents

Primary sources

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