Contraceptive implant

What is it?

An implant is a hormonal method of contraception that slowly releases a dose of progestogen. It is a small flexible rod inserted just underneath the skin in the upper arm. The implant must be fitted by a trained health professional and is normally fitted within the first five days of your period and provides immediate protection. If the implant is fitted on any other day, an additional method of protection must also be used for 7 days.

How does it work?²

The implant has a slow release of the hormone progestogen and produces the contraceptive effect by:

• Mainly stopping the ovaries from releasing an ovum
• Thickening the mucus of the cervix to act as a barrier to sperm
• Stopping the fertilised ovum from settling by keeping the lining of the womb thin

How effective is it?¹

Once in place, implants last for a period of up to 3 years, or until removed, and is over 99% effective.

What are the benefits of the implant?²

• You do not have to remember to take a daily pill
• Does not interrupt sex
• Suitable for breastfeeding women
• No oestrogen related side effects
• You are protected against pregnancy for 3 years, but normally fertility returns immediately after removing the implant
• Hormones do not have to go through the stomach so you are not affected by sickness or diarrhoea
• It offers some protection against pelvic inflammatory disease
• It may protect against cancer of the womb

What are the drawbacks?²

• Your periods may change
• It requires a small procedure to fit and remove
• It does not protect against sexually transmitted infections (STIs)

Are there side effects?²

• Periods can be irregular
• Can increase the chance of spots, headaches
• Some women report having tender breasts and bloating
• Some women develop cysts on their ovaries - but these are very rarely serious and don’t usually require any treatment
• Increased breast cancer risk

You should not use the implant if you are/have had any of the following²:

• You might be pregnant
• Don’t want any changes to your periods
• Have breast cancer or have had it in the last 5 years
• Active liver disease
• Have had a heart attack or stroke
• Have unexplained vaginal bleeding

What if I want to become pregnant?²

The implant can be removed at any time. Your periods and normal fertility will return quickly.

What do I do if I forget to book my 3-year appointment for my implant to be replaced?

You should make an appointment to see your doctor to have your implant replaced as soon as you remember. It is important to have your implant changed at the right time. If it is not, you will not be protected against pregnancy.

1 NHS direct. Health encyclopedia – contraceptive implants and injections

2. fpa. Sex/sexual health – contraception – the contraception implant