Side Effects of Nexplanon
The most common side effect of Nexplanon is irregular menstrual bleeding, affecting the majority of users, with other frequent side effects including headache, weight gain, mood changes, acne, and breast pain. 1
Most Common Side Effects
Menstrual Changes (Most Prevalent)
- Bleeding pattern changes occur in approximately 80% of users and represent the primary reason for discontinuation 1
- Patterns include:
Important caveat: One in ten women discontinue the implant specifically due to unfavorable bleeding changes 1. Prolonged or heavy bleeding is significantly associated with early removal (within 12 months) 2.
Other Frequent Side Effects (≥10%)
According to FDA labeling, the following occur in ≥10% of users 1:
- Headache: 18.75% report this symptom 3
- Weight gain: 37-64% experience BMI increases, with average increase of 3.2% 2
- Acne: 10% of users 3
- Breast pain: 18.75% 3
- Vaginitis (vaginal inflammation)
- Abdominal/stomach pain
- Viral infections (sore throats, flu-like symptoms)
Neuropsychiatric Effects
- Mood swings, nervousness, or depressed mood: 10% report mood changes 2
- These symptoms are significantly associated with early discontinuation (p=0.02) 5
- Critical point: History of depression should NOT deter implant placement, as relatively few remove it for mood complaints 2
Less Common but Notable Side Effects
- Back pain
- Nausea
- Dizziness
- Painful periods
- Loss of libido: 2.5% 3
Serious but Rare Complications
Insertion/Removal Complications 1
- Deep or failed insertion requiring imaging and potentially surgery
- Migration to blood vessels, including pulmonary artery (can cause chest pain, shortness of breath, cough, hemoptysis)
- Local site reactions: pain, swelling, bruising, numbness, tingling, infection, scarring/keloid formation
- Nerve or blood vessel injury in the arm
- Vasovagal reactions (fainting, dizziness, blood pressure drop)
Other Serious Risks
- Ectopic pregnancy: Slightly higher risk if pregnancy occurs while using Nexplanon 1
- Ovarian cysts: Usually resolve spontaneously but may require surgery 1
- Blood clots: Increased risk, especially in smokers (deep vein thrombosis, pulmonary embolism, stroke, heart attack) 1
- Breast cancer: Unknown if Nexplanon changes risk; contraindicated in current or past breast cancer 1
Management of Bleeding Irregularities
When patients report problematic bleeding 4:
- For spotting or light bleeding: NSAIDs for 5-7 days
- For heavy or prolonged bleeding:
- NSAIDs for 5-7 days
- Hormonal treatment (low-dose combined oral contraceptives or estrogen) for 10-20 days
- Antifibrinolytic agents (tranexamic acid) for 5 days
- Always reassure that bleeding changes are expected and offer removal if desired
Clinical Context
Real-world continuation rates are significantly lower than clinical trials: The one-year continuation rate in practice settings is approximately 62% compared to 83% in the landmark CHOICE study (p<0.001) 5. Side effects are reported by 82% of users in real-world settings 5, though most continue use beyond 12 months (76%) 2.
Key counseling point: Thorough pre-insertion counseling about expected side effects, particularly bleeding changes, is essential to minimize early discontinuation 3, 6.