An implant is a small flexible rod that is placed just under your skin in your upper arm (under local anaesthetic).  It releases a progestogen hormone which is similar to the hormone naturally produced.

It works by stopping the ovaries from releasing an egg each month (ovulation).  It also thickens the mucus in the cervix preventing sperm reaching the egg and thins the lining of the uterus so it is less likely to accept a fertilised egg.