Implanon implant contains etonogestrel, a hormone that prevents ovulation (the release of an egg from an ovary). Etonogestrel also causes changes in your cervical mucus and uterine lining, making it harder for sperm to reach the uterus and harder for a fertilized egg to attach to the uterus.

Implanon implant is used as contraception to prevent pregnancy. The medicine is contained in a small plastic rod that is implanted into the skin of your upper arm. The medicine is released slowly into the body. The rod can remain in place and provide continuous contraception for up to 3 years.

Implanon may also be used for purposes not listed in this medication guide.

You should not use an Implanon if you have any of the following conditions: unusual vaginal bleeding, liver disease or liver cancer, or if you have ever had breast or uterine cancer, a heart attack, a stroke, or a blood clot.

Do not use if you are pregnant or if you have recently had a baby.

Using an Implanon implant can increase your risk of blood clots, stroke, or heart attack, especially if you have certain other conditions, or if you are overweight.

Smoking can greatly increase your risk of blood clots, stroke, or heart attack. You should not use Implanon if you smoke and are over 35 years old.

Before receiving the Implanon implant, tell your doctor if you have diabetes, high blood pressure, high cholesterol, gallbladder disease, kidney disease, an ovarian cyst, headaches, a history of depression, if you are overweight, or if you are allergic to numbing medicines.

The Implanon implant is inserted through a needle into the skin of your upper arm. The medicine is released slowly into the body from the implant. The implant can remain in place to provide continuous contraception for up to 3 years.

You will most likely have irregular and unpredictable periods while using the Implanon implant. Tell your doctor if your periods are very heavy or long-lasting, or if you miss a period (you may be pregnant). If you need surgery or medical tests or if you will be on bed rest, you may need to have your Implanon implant removed for a short time. Any doctor or surgeon who treats you should know that you have an Implanon implant.

The Implanon implant must be removed by the end of the third year after it was inserted and may be replaced at that time with a new implant. If you choose not to replace the implant, your ability to get pregnant will return quickly. Start using another form of birth control right away if you wish to avoid an unintended pregnancy.

Implanon is inserted through a needle (under local anesthesia) into the skin of your upper arm, just inside and above the elbow. After the implant is inserted, your arm will be covered with 2 bandages. Remove the top bandage after 24 hours, but leave the smaller bandage on for 3 to 5 days. Keep the area clean and dry.

The timing of when you will receive the Implanon implant depends on whether you were using birth control before, and what type it was.

You should be able to feel the implant under your skin. Tell your doctor if you cannot feel the implant at any time while it is in place.

Implanon can remain in place for up to 3 years. If the implant is placed correctly, you will not need to use back-up birth control. Follow your doctor's instructions.

You may have irregular and unpredictable periods while using the Implanon implant. Tell your doctor if your periods are very heavy or long-lasting, or if you miss a period (you may be pregnant).

If you need surgery or medical tests or if you will be on bed rest, you may need to have your Implanon implant removed for a short time. Any doctor or surgeon who treats you should know that you have an Implanon implant.

Have regular physical exams and mammograms, and self-examine your breasts for lumps on a monthly basis while using Implanon.

The Implanon implant must be removed by the end of the third year after it was inserted and may be replaced at that time with a new implant. After the implant is removed, your ability to get pregnant will return quickly. If the implant is not replaced with a new one, start using another form of birth control right away if you wish to prevent pregnancy.

Call your doctor at once if it feels like the implant may be bent or broken while it is in your arm.

Usual Adult Dose for Contraception:

One 68 mg implant inserted subdermally. The implant should not be left in place more than three years.

The timing of the Implanon implant insertion must be done according to the patient's recent history, as follows:

If no preceding hormonal contraceptive use in the past month, the implant must be inserted between Days 1 through 5, (counting the first day of menstruation as "Day 1"), even if the woman is still bleeding.

If switching from a combination hormonal contraceptive, the Implanon implant may be inserted anytime within seven days after the last active (estrogen plus progestin) oral contraceptive tablet, anytime during the seven-day ring-free period of NuvaRing (etonogestrel/ethinyl estradiol vaginal ring), or anytime during the seven-day patch-free period of a transdermal contraceptive system.

If switching from a progestin-only method, the implant must inserted as follows: if switching from a progestin-only pill, any day of the month (do not skip any days between the last pill and insertion); if switching from a progestin-only implant, insert the implant on the same day as contraceptive implant removal; if switching from a progestin-containing IUD, insert the implant on the same day as contraceptive implant removal; if switching from a contraceptive injection, insert the implant on the day when the next injection would be due.

Following first trimester abortion or miscarriage: the Implanon implant may be inserted immediately following a complete first trimester abortion. If it is not inserted within five days following a first trimester abortion, follow the instructions under no preceding hormonal contraceptive use in the past month.

Following delivery or a second trimester abortion: the Implanon implant may be inserted between 21 to 28 days postpartum if not exclusively breast feeding or between 21 to 28 days following second trimester abortion. If more than four weeks have elapsed, pregnancy should be excluded and the patient should use a non-hormonal method of birth control during the first seven days after the insertion. If the patient is exclusively breast-feeding, insert the implant after the fourth postpartum week.

Using Implanon can increase your risk of blood clots, stroke, or heart attack. You are even more at risk if you have high blood pressure, diabetes, high cholesterol, or if you are overweight. Your risk of stroke or blood clot is highest during your first year of using this medicine.

Smoking can greatly increase your risk of blood clots, stroke, or heart attack. Your risk increases the older you are and the more you smoke. You should not use this medicine if you smoke and are over 35 years old.

Do not use Implanon if you are pregnant. If you have recently had a baby, wait at least 3 weeks (4 weeks if breast-feeding) before receiving an Implanon implant.

You may need to have a negative pregnancy test before receiving the implant.

You should not use Implanon if you are allergic to etonogestrel, or if you have:

• a history of heart attack, stroke, or blood clot;

• a history of hormone-related cancer such as breast or uterine cancer;

• unusual vaginal bleeding that has not been checked by a doctor; or

• liver disease or liver cancer.

To make sure Implanon is safe for you, tell your doctor if you have:

• diabetes;

• high cholesterol or triglycerides, or if you are overweight;

• high blood pressure;

• headaches;

• gallbladder disease;

• a history of depression; or

• if you are allergic to numbing medicines.

The Implanon implant should not be used in girls younger than 18 years old.

Do not use the implant if you are breast-feeding a baby younger than 4 weeks old.

Since Implanon is given as an implant by a healthcare professional, you will not be on a frequent dosing schedule. Be sure to see your doctor for removal of the implant by the end of the third year.

If the implant is correctly inserted, an overdose of etonogestrel is highly unlikely.

Do not smoke while using Implanon, especially if you are older than 35 years of age. Smoking can increase your risk of blood clots, stroke, or heart attack caused by Implanon.

Implanon will not protect you from sexually transmitted diseases - including HIV and AIDS. Using a condom is the only way to protect yourself from these diseases.

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

Call your doctor at once if you have:

• warmth, redness, swelling, or oozing where the implant was inserted;

• severe pain or cramping in your pelvic area (may be only on one side);

• sudden numbness or weakness (especially on one side of the body), sudden severe headache, slurred speech, problems with vision or balance;

• sudden cough, wheezing, rapid breathing, coughing up blood;

• pain, swelling, warmth, or redness in one or both legs;

• chest pain or heavy feeling, pain spreading to the jaw or shoulder, nausea, sweating, general ill feeling;

• swelling in your hands, ankles, or feet;

• jaundice (yellowing of the skin or eyes);

• a breast lump; or

• symptoms of depression (sleep problems, weakness, tired feeling, mood changes).

Common Implanon side effects may include:

• changes in your menstrual periods;

• light menstrual bleeding or spotting;

• stomach pain;

• breast tenderness;

• acne;

• weight gain;

• vaginal itching or discharge; or

• problems with contact lenses.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Tell your doctor about all medicines you use, and those you start or stop using during your while your Implanon is in place, especially:

• bosentan;

• griseofulvin;

• rifampin;

• St. John's wort;

• topiramate;

• medicine to treat HIV or AIDS;

• a barbiturate - butabarbital, secobarbital, phenobarbital (Solfoton); or

• seizure medicine - carbamazepine, felbamate, oxcarbazepine, phenytoin.

This list is not complete. Other drugs may interact with etonogestrel, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.