Implant Side Effects: A Complete Guide to What to Expect
Choosing a method of long-acting reversible contraception (LARC) is a significant decision for your reproductive health. The contraceptive implant, often known by the brand name Nexplanon, is a small, flexible plastic rod placed under the skin of your upper arm. While it is over 99% effective, many people feel hesitant due to potential implant side effects.
Understanding how your body might react to hormonal contraception allows you to make an informed choice. In this guide, we’ll explore the common, rare, and temporary changes you might experience, alongside expert advice on managing them.
How the Implant Works
The implant works by steadily releasing a hormone called etonogestrel into your bloodstream. This is a progestogen-only method, meaning it does not contain oestrogen. According to the NHS, it prevents pregnancy by thickening cervical mucus, thinning the womb lining, and occasionally preventing ovulation.
Because it alters your natural hormonal changes, your body needs a period of adjustment. Most clinicians suggest waiting at least three to six months to see how your system settles.
Common Implant Side Effects
Most people experience some form of side effect, though they are often mild and subside after the first few months. Research published in The Lancet suggests that while individual experiences vary, certain patterns are frequently reported in clinical trials.
- Irregular periods: This is the most frequently reported side effect. Your irregular periods may become lighter, heavier, longer, or stop altogether (amenorrhea).
- Headaches: Mild headaches are common during the initial weeks of insertion.
- Breast tenderness: You may notice increased sensitivity or breast tenderness as your body adjusts to the progestogen.
- Mood swings: Some users report changes in mood or emotional stability. A study in Nature explored the complex link between hormonal birth control and mental wellbeing.
- Acne: Existing skin conditions may flare up, or you might notice new skin irritation or breakouts.
The Impact on Your Bleeding Pattern
The British Medical Journal (BMJ) notes that changes in bleeding patterns are the primary reason individuals choose to have the implant removed early. It is important to discuss your medical history with a healthcare provider before insertion to understand your personal risk factors.
Common bleeding variations include:
- Frequent spotting or “breakthrough bleeding.”
- Infrequent bleeding.
- A total cessation of periods (which is medically safe).
Side Effects Comparison Table
To help you weigh the birth control options, here is a breakdown of common versus rare symptoms associated with the implant.
| Symptom Type | Potential Side Effects | Frequency |
|---|---|---|
| Gynaecological | Spotting, irregular bleeding, pelvic pain | Very Common |
| Physical | Nausea, weight changes, insertion site bruising | Common |
| Dermatological | Acne, oily skin, hair thinning | Common |
| Serious/Rare | Infection, device migration, ectopic pregnancy | Very Rare |
Procedural and Local Side Effects
Beyond the systemic implant side effects, the physical act of insertion and removal can cause localised issues. The Mayo Clinic highlights that the procedure involves a local anaesthetic, which may cause a stinging sensation.
After insertion, you may experience:
- Bruising or swelling around the insertion site.
- A small scar where the rod was placed.
- Mild discomfort in the arm for a few days.
It is vital that you can always feel the rod under your skin. If you cannot locate it, contact your healthcare provider immediately to ensure it hasn’t moved.
Rare but Serious Risks
While the implant is highly safe for most, some rare complications require medical attention. Organisations like the American College of Obstetricians and Gynecologists (ACOG) monitor these risks closely.
Ectopic pregnancy is a rare risk; if you become pregnant while the implant is in place, there is a higher chance the pregnancy will develop outside the womb. Additionally, if you experience severe pelvic pain, it is essential to rule out complications. The MHRA in the UK provides ongoing safety updates regarding medical devices to ensure patient safety.
When to Consult Your GP
You should seek advice from a doctor or sexual health clinic if you experience any of the following:
- You cannot feel the implant in your arm.
- The shape of the implant feels different or bent.
- You notice changes in your skin, such as yellowing of the eyes (jaundice).
- Persistent, heavy vaginal bleeding that affects your quality of life.
- Signs of infection at the site (redness, heat, pus).
For more detailed information on managing these symptoms, the Family Planning Association (FPA) and Sexwise offer excellent resources for UK residents.
Summary of Outlook
The contraceptive implant is a “fit and forget” method that provides peace of mind for three years. While implant side effects like irregular bleeding or mood shifts can be frustrating, they often resolve as your body reaches a new equilibrium. Always consult with a professional to ensure the implant aligns with your current health status and lifestyle. Detailed guidance can also be found through the Faculty of Sexual and Reproductive Healthcare (FSRH).
Frequently Asked Questions (FAQs)
Can the implant cause weight gain?
Weight gain is a commonly reported side effect, though clinical evidence is mixed. According to Planned Parenthood, some people may experience changes in appetite or water retention due to hormonal changes, but it is not a guaranteed outcome for everyone.
Is it normal for my period to stop completely?
Yes, it is perfectly normal. Around 1 in 5 people using the implant will find that their periods stop. This is not harmful to your body; it simply means the hormone is effectively preventing the thickening of the womb lining. You can find more comparative data on the Contraception Choices website.
How soon do side effects start?
Side effects typically begin within the first few weeks after insertion. However, the World Health Organization (WHO) notes that most long-acting reversible contraception symptoms improve significantly after the first three months of use. If symptoms persist beyond six months, you may wish to discuss alternative birth control options with your doctor.
What should I do if I think my implant has moved?
If you cannot feel the rod in your arm, you should use a backup method of contraception, such as condoms, and book an appointment with your clinic immediately. Information from the CDC suggests that while migration is rare, it requires professional imaging to locate and safely remove the device.
