A small flexible rod placed under the skin of the inner upper arm. The hormone progestogen is released very slowly from this rod and works by preventing ovulation and thickening the cervical mucus.

Advantages

• Very effective - 99%.
• The implant remains effective for a long period - only needing to be replaced every 3 years.
• It is easily reversible - once removed normal fertility returns immediately.

Disadvantages

• Periods are often irregular particularly during the first year, or may be missed.
• Some women may gain weight.
• There may be temporary side effects such as headaches, mood changes or breast tenderness.
• Insertion of the implant requires a local anaesthetic, and there may be some bruising and swelling for a day or two after insertion.
• The implant can be felt beneath the skin.