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(etonogestrel) Implant


IMPLANON (etonogestrel implant) is a progestin-only, soft, flexible implant preloaded in a sterile, disposable applicator for subdermal use. The implant is off-white, non-biodegradable and 4 cm in length with a diameter of 2 mm (see Figure 22). Each implant consists of an ethylene vinylacetate (EVA) copolymer core, containing 68 mg of the synthetic progestin etonogestrel, surrounded by an EVA copolymer skin. Once inserted subdermally, the release rate is 60 to 70 mcg/day in Week 5 to 6 and decreases to approximately 35 to 45 mcg/day at the end of the first year, to approximately 30 to 40 mcg/day at the end of the second year, and then to approximately 25 to 30 mcg/day at the end of the third year. IMPLANON is a progestin-only contraceptive and does not contain estrogen. IMPLANON does not contain latex and is not radio-opaque.

Figure 22 (Not to scale)

The implant - Illustration

Etonogestrel [13-Ethyl-17-hydroxy-11-methylene-18,19-dinor-17α-pregn-4-en-20-yn-3-one], structurally derived from 19­nortestosterone, is the synthetic biologically active metabolite of the synthetic progestin desogestrel. It has a molecular weight of 324.46 and the following structural formula (Figure 23).

Figure 23

IMPLANON® (etonogestrel) Structural Formula Illustration

What are the possible side effects of etonogestrel implant (Implanon, Nexplanon)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these serious side effects:

  • warmth, redness, swelling, or oozing where the implant was inserted;
  • sudden numbness or weakness, especially on one side of the body;
  • severe pain or cramping in your pelvic area (may be only on one side);
  • sudden severe headache, confusion, pain behind the eyes, problems with vision, speech, or...

Read All Potential Side Effects and See Pictures of Implanon »

What are the precautions when taking etonogestrel implant (Implanon)?

Before having the rod placed, tell your doctor or pharmacist if you are allergic to etonogestrel; or to other progestins; or to any anesthetics or antiseptics that might be used in the procedure; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: abnormal breast exam, blood clots (e.g., in the legs, eyes, lungs), breast cancer, depression, high blood pressure, low levels of "good" cholesterol (HDL), diabetes, gall bladder disease, heart disease (e.g., chest pain, heart attack), history of yellowing eyes/skin (jaundice) during pregnancy or while using birth...

Read All Potential Precautions of Implanon »

Last reviewed on RxList: 11/21/2014
This monograph has been modified to include the generic and brand name in many instances.


Implanon - User Reviews

Implanon User Reviews

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