From the Guidelines
Implanon (etonogestrel) can cause several side effects, with irregular menstrual bleeding being the most common, including unscheduled spotting or light bleeding and amenorrhea, especially during the first year of use, as reported in a pooled analysis of data from 11 clinical trials 1. Many women experience changes in their bleeding patterns, including longer or shorter bleeding, spotting between periods, or no bleeding at all. Other common side effects include:
- headaches
- mood changes
- depression
- weight gain
- acne
- decreased sex drive
- breast pain or tenderness Some women may experience pain, bruising, or infection at the implant site. More serious but rare side effects include:
- blood clots
- stroke
- heart attack
- high blood pressure
- gallbladder problems
- liver tumors There's also a small risk of the implant migrating from its original position or being difficult to remove. If you experience severe abdominal pain, chest pain, shortness of breath, severe headaches, eye problems, or yellowing of the skin or eyes while using Implanon, seek immediate medical attention. These side effects occur because etonogestrel is a progestin hormone that affects various body systems beyond just preventing pregnancy. Most side effects are mild and often improve after the first few months of use, as noted in a study on contraception for adolescents 1. It is essential to discuss these potential side effects with a healthcare provider before insertion of the implant, as enhanced counseling about expected bleeding patterns and reassurance that bleeding irregularities are generally not harmful has been shown to reduce discontinuation in clinical trials 1.
From the FDA Drug Label
It is possible to die or be permanently disabled from a problem caused by a blood clot, such as heart attack or stroke. Some examples of serious blood clots are blood clots in the: legs (deep vein thrombosis) lungs (pulmonary embolus) eyes (loss of eyesight) heart (heart attack) brain (stroke) The most common side effects of Etonogestrel ... are: tissue irritation inside your vagina or on your cervix headache (including migraine) mood changes (including depression, especially if you had depression in the past) Other serious risks include: Toxic Shock Syndrome (TSS) ... liver problems, including liver tumors high blood pressure gallbladder problems Less common side effects seen with combination hormonal birth control include: Blotchy darkening of your skin, especially on your face High blood sugar, especially in women who already have diabetes High fat (cholesterol, triglycerides) levels in the blood
The potential side effects of Implanon (etonogestrel) include:
- Serious blood clots, such as deep vein thrombosis, pulmonary embolus, and heart attack
- Toxic Shock Syndrome (TSS)
- Liver problems, including liver tumors
- High blood pressure
- Gallbladder problems
- Common side effects, such as headache, mood changes, and tissue irritation
- Less common side effects, such as blotchy darkening of the skin, high blood sugar, and high fat levels in the blood 2 Note that Implanon is not explicitly mentioned in the provided drug labels, but etonogestrel is, which is the active ingredient in Implanon. However, the provided drug labels are for Etonogestrel and ethinyl estradiol vaginal ring, not for Implanon. The FDA drug label does not answer the question.
From the Research
Potential Side Effects of Implanon
The potential side effects of Implanon (etonogestrel) include:
- Abnormal bleeding patterns, such as infrequent bleeding, amenorrhea, prolonged bleeding, and metromenorrhagia (frequent and heavy bleeding) 3, 4, 5
- Mood changes, such as anxiety and depression 3, 4, 5
- Acne and hirsutism 3, 4, 5
- Breast tenderness and mastalgia 3, 4
- Headache 4, 5, 6
- Weight gain 4, 5, 6
- Dizziness 5
- Loss of libido 4
- Pain at the insertion site 4
Discontinuation Rates
The discontinuation rates of Implanon due to side effects are significant, with studies reporting rates ranging from 19.5% to 24% 3, 5. The most common reasons for discontinuation are bleeding disturbances, followed by other side effects such as acne and mood changes.
Counseling and Satisfaction
Preinsertion counseling is crucial in ensuring satisfaction with Implanon, as it helps to manage expectations and reduce the risk of discontinuation due to side effects 7, 5. Studies have shown that patients who are well-informed about the potential side effects of Implanon are more likely to be satisfied with the method and continue using it 4.