The contraceptive implant is a popular form of contraceptive, particularly suited to women who have trouble remembering to take the contraceptive pill at the same time every day.
The implant is a small flexible rod (40mm long) that contains progestogen and is inserted into the upper arm. Currently, Nexplanon is the only contraceptive implant that can be prescribed in the UK, as previous brands (such as Implanon) were discontinued.
Nexplanon is easier to insert than previous models and also contains barium, so it can be seen on an X-ray.
Fitting the implant
The contraceptive implant can only be fitted by a trained doctor. The doctor will numb the area with a local anaesthetic and then insert the implant into your upper arm. This is usually done within five days of the beginning of your period.
How it works
The hormone contained in the contraceptive implant, progestogen, is released steadily into the bloodstream. Once in the bloodstream, it works in a similar way to other hormonal contraceptives, by first stopping the release of an egg from the ovaries (ovulation).
It then thickens the cervical mucus to inhibit the movement of sperm to the womb, and finally it thins the lining of the uterus wall. This means that, in the unlikely event that an egg was to be released and then fertilised, it would not be able to imbed itself in the uterine lining to grow.
The contraceptive implant is more than 99% effective at preventing pregnancy. Statistically, this means that out of every 1,000 women who use the implant, less than one will get pregnant. This is compared to the 80 out of every 100 women who would get pregnant if they did not use any form of contraception.
The implant is a convenient and safe alternative to oral contraceptives for women who may have trouble remembering to take a pill every day, or if they react badly to the oestrogen in combined pills.
Once the implant is fitted it will be effective for three years, and it does not affect fertility once the implant is taken out. Unlike many contraceptive pills, the implant is safe for women who are breastfeeding. If you do experience side effects, you can have the implant taken out at any time.
Side effects of the implant
You will likely notice that the pattern of your periods will change. This could mean that they become heavier or lighter, or just simply irregular. It could take up to a year for a regular pattern to be established.
Other side effects reported by those using the contraceptive implant are fluid retention, an increase in acne and breast discomfort. Usually, side effects that do occur are mild and settle after three to six months.
Women that can use it
Some enzyme-inducing drugs may make the implant less effective. These include medicines to treat HIV, tuberculosis and epilepsy, and the herbal remedy St John's Wort. You should disclose your full medical history to your doctor, as some conditions may mean the contraceptive implant is not suitable for you.