Etonogestrel belongs to the class of medications called hormonal contraceptives. Specifically, it is a hormone belonging to the family of drugs called progestins. Progestins are hormones similar to progesterone, which is produced by the ovaries.

The etonogestrel implant is used to prevent pregnancy for up to 3 years. It works by preventing ovulation (the release of an egg by the ovaries) and changing the mucus produced by the cervix, making it difficult for sperm to enter the uterus. This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

This medication is in the form of a 4 cm long implant that is inserted subdermally (just under the skin) of the inner, upper arm, by your doctor. It may be left in place for up to three years, however it may be removed by your doctor at any point in time. It is usually inserted between Day 1 and Day 5 of your menstrual cycle.

When first inserted, the implant releases up to 60 to 70 mcg of etonogestrel daily. This gradually declines over time.

When the implant has been inserted, you should be able to feel it under the skin. Although not common, the implant can migrate deeper to where it can no longer be felt. If you cannot feel the implant, contact your doctor. The implant could possibly break or bend in your arm; however, this should not affect how the implant works.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Each white to off-white, soft, radiopaque, non-biodegradable, flexible implant rod, with a length of 4 cm and 2 mm in diameter, contains 68 mg of etonogestrel. Implant core: barium sulfate (15 mg), ethylene vinyl acetate copolymer (28% vinyl acetate, 43 mg), and magnesium stearate (0.1 mg); implant skin: ethylene vinyl acetate copolymer (15% vinyl acetate, 15 mg).

Do not use this medication if you:

• are allergic to etonogestrel or any ingredients of the medication
• are or may be pregnant
• have a history of blood clots or clotting disorders
• have liver tumours
• have active liver disease
• have undiagnosed vaginal bleeding
• have, may have, or have a history of breast cancer or suspected breast cancer
• have, may have, or have a history of a cancer that is sensitive to progestin

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• acne
• bruising, pain, swelling, or itching at the insertion site
• constipation
• dandruff (flaking scalp)
• decreased interest in sexual activity
• diarrhea
• drowsiness
• excessive hair growth
• fatigue
• gas
• hair loss
• headache
• hives
• hot flushes
• increased appetite
• infection where the implant is inserted
• itchiness
• mood swings
• nausea
• oily skin
• painful menstrual periods
• rash
• sore throat
• stuffy or runny nose
• vaginal pain
• vomiting
• weight changes
• yellowish-brown patches on the skin

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• abdominal pain
• abnormal vaginal bleeding
• anxiety
• back pain
• breast enlargement
• breast lumps
• breast pain or tenderness
• fluid retention (e.g., swelling of the feet, ankles, or lower leg)
• flu-like symptoms (e.g., fever, sore throat, headache)
• implant moving out of place
• increased blood pressure
• migraine
• muscle, joint, or bone pain
• nervousness
• ovarian cyst
• signs of a blood clot in the arm or leg (tenderness, pain, swelling, warmth, or redness in the arm or leg) or lungs (difficulty breathing, sharp chest pain that is worst when breathing in, coughing, coughing up blood, sweating, or passing out)
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• symptoms of a urinary tract infection (e.g. pain when urinating, urinating more often than usual, low back or flank pain)
• trouble sleeping
• vaginal discharge

Stop taking the medication and seek immediate medical attention if any of the following occur:

• abdominal or pelvic pain (sudden, severe, or continuing)
• signs of a blood clot in the lung (e.g., sudden, sharp chest pain, coughing blood, sudden shortness of breath)
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of a heart attack (e.g., chest pain or pressure, pain extending through shoulder and arm, nausea and vomiting, sweating)
• signs of stroke (e.g., sudden or severe headache; sudden loss of coordination; vision changes, sudden slurring of speech; or unexplained weakness, numbness, or pain in arm or leg)
• sudden loss of vision or double vision

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Blood clots: As with any hormonal contraceptives, there is a risk of developing blood clots. Tell your doctor if you have a history of blood clots or are at risk of developing blood clots. Stroke symptoms, such as confusion, difficulty speaking, loss of coordination, sudden headache or vision changes may occur as a result of a clot blocking blood flow to the brain. Symptoms of blood clots in other parts of the body include: sharp pain in the chest, pain in the calf, sudden shortness of breath, or coughing up blood. If you experience any of these symptoms, contact your doctor immediately, as blood clots can be life threatening.

Blood pressure: Occasionally, high blood pressure may develop with the use of hormonal contraceptives. People with high blood pressure should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. You may need to visit your doctor more frequently to have your blood pressure checked while using this medication.

Body weight: The safety and effectiveness of the etonogestrel implant have not been determined for women who weigh more than 30% over their ideal body weight .  If you are overweight, this medication may become less effective over time and your health care professional may suggest replacing it sooner.

Breast and cervical cancer: Certain cancers, such as some breast and cervical cancers, are sensitive to hormones. Using hormonal contraceptives may increase the incidence of these cancers. Women with a history of breast or cervical cancers should not use hormonal birth control, as the role of female sex hormones in these diseases has not been fully determined.

Cholesterol: Etonogestrel can cause increased blood cholesterol levels. If you are at risk of developing high cholesterol or you have high cholesterol levels before starting etonogestrel, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Depression: Hormones, such as etonogestrel, have been known to cause mood swings and symptoms of depression. If you have depression or a history of depression, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you experience symptoms of depression such as poor concentration, changes in weight, changes in sleep, decreased interest in activities, or notice them in a family member who is taking this medication, contact your doctor as soon as possible.

Diabetes: Etonogestrel may cause slight increases in blood sugar levels (may cause a loss of blood glucose control) and glucose tolerance may change. People with diabetes may find it necessary to monitor their blood sugar more frequently while using this medication.

If you have diabetes, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Eye disorders: Women who are using hormonal contraceptives such as this implant may experience vision changes. Contact lenses may not fit as well as they used to, especially if you have hard contact lenses. Soft contact lenses usually do not cause problems. If your contact lenses feel uncomfortable, talk to your eye doctor.

Irregular menstruation: Irregular menstrual patterns are common among women using progestin-only contraceptives. If you notice changes in your usual menstrual patterns, check with your doctor. If you go a prolonged time without bleeding, you should have a pregnancy test.

Liver function: This medication may cause changes in liver function. If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Return to fertility: There is no evidence that the use of the contraceptive implant leads to decrease in fertility. There have been reports of pregnancy occurring within the first 2 weeks after removing the implant. If pregnancy is not desired, an alternative birth control method should be used immediately after removing the implant, or a new implant should be inserted.

Sexually transmitted infections (STIs): This medication, as with other hormonal contraceptives, does not protect against HIV/AIDS and other STIs (sexually transmitted infections ­– formerly known as sexually transmitted diseases or STDs). It is recommended that latex condoms be used in combination with this medication for protection against these infections.

Pregnancy: This medication should not be used during pregnancy. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: This medication passes into breast milk. If you are breast-feeding and are using the etonogestrel implant, it may affect the quality and amount of breast milk produced. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children or adolescents.

There may be an interaction between etonogestrel and any of the following:

• anticoagulants (e.g., apixaban, heparin, low molecular weight heparins, rivaroxaban, warfarin)
• aprepitant
• azole antifungals (e.g., fluconazole, itraconazole, ketoconazole)
• barbiturates (e.g., butalbital, pentobarbital, phenobarbital)
• bosentan
• cannabis
• cholestyramine
• cladribine
• cobicistat
• colesevelam
• colestipol
• corticosteroids (e.g., dexamethasone, hydrocortisone, prednisone)
• cyclosporine
• diabetes medications (e.g., canagliflozin, glyburide, insulin, linagliptin, lixisenatide, metformin, rosiglitazone)
• efavirenz
• grapefruit juice
• HIV protease inhibitors (e.g., atazanavir, darunavir, indinavir, lopinavir, saquinavir)
• lumacaftor and ivacaftor
• mifepristone
• modafinil
• mycophenolate
• octreotide
• pomalidomide
• retinoic acid medications (e.g., acitretin, etretinate, tretinoin)
• rifabutin
• rifampin
• St. John's wort
• seizure medications (e.g., carbamazepine, eslicarbazepine, lacosamide, lamotrigine, oxcarbazepine, phenytoin, rufinamide, topiramate, zonisamide)
• selegiline
• thalidomide
• tranexamic acid
• triazolam
• ulipristal

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.