Background
What is a contraceptive implant?
An implant is a small flexible rod about an inch long but only 2mm across that contains a hormone called etonorgestrel. The current implant in use is called Nexplanon. It is licensed to be used for 3 years. It is inserted just under the skin in the upper arm.
How does an implant work?
The hormone in the implant work mainly by preventing ovulation (egg production). It also affects the mucus at the cervix (neck of the womb) so that sperm can’t get though. It also thins the womb lining so that if an egg does get fertilised it is harder for it to be implanted in the womb.
What are the benefits of an implant?
Nexplanon is a very reliable form of contraception with less than 1 in 1000 women becoming pregnant over 3 years. There is also some evidence that it may help with painful periods, and possibly with pain related to endometriosis.
What are the potential problems with an implant?
The implant changes the pattern of bleeding that a woman has. Less than a quarter of women with an implant will have regular bleeds. Most women have infrequent bleeds, with around 1 in 5 having no bleeding at all. Up to a quarter of women may have prolonged or frequent bleeding. If this happens early on then sometimes a short course of the contraceptive pill can help settle it down
In addition to the effects on bleeding, some patients report a worsening in acne with the implant. However some report an improvement in their acne.
There is no evidence that the implant is associated with weight gain, headaches, mood changes, cancer risk or blood clot risk.
With previous implants if they were inserted too deeply occasionally they were difficult to find and remove. The Nexplanon implants contain a substance that shows up on Xray to overcome this problem.
Very rare risks of insertion include allergic reactions to the local anaesthetic, or damage to nerves or blood vessels
