Injectable Hormonal Contraceptive - Depo
Depo is a contraceptive injection effective against pregnancy for 12 weeks.
What is it?
Depo Provera/Depo Ralovera (Depo) is a progestogen-only contraceptive injection. It is given into the muscle (usually the upper arm or buttocks) every 12 weeks by a doctor or nurse. The hormone is slowly released into the body over the 12 weeks.
How does it work?
Depo works by:
• preventing the body from releasing an ovum (egg) every month (this is its main action)
• thickening mucus in the cervix to prevent sperm penetration
• changing the lining of the uterus (womb), making it difficult for a fertilised egg to implant.
How effective is it?
Depo is more than 99% effective, which means less than one in 100 women will get pregnant during one year of use.
If given within five days of the start of a normal period, Depo is effective from the day of the injection. If given after the fifth day of a period, other back-up contraception should be used for the next seven days (eg condoms). Contraceptive cover will last for three months after each injection.
Who can use it?
Depo is suitable for most women. Women who have difficulty remembering to take daily contraception may prefer this method.
Depo is not recommended for women who:
• are allergic to the drug (this is very rare)
• are possibly pregnant
• have active liver disease
• have developed depression when taking oral contraception
• have a past history of a depressive illness or post-natal depression
• have undiagnosed vaginal bleeding
• have had a heart attack
• may be distressed by abnormal or unpredictable bleeding patterns
• have high risk of osteoporosis
What are the advantages of Depo?
• Depo can make periods lighter and less painful (though they can be irregular)
• Many women do not get periods after they have had one or two injections (with some seeing this as convenient)
• It may relieve premenstrual syndrome (PMS)
• The date of the next injection is the only thing to be remembered. This helps to make Depo a highly effective contraceptive method
• As Depo only contains the hormone progestogen, it is suitable for women who can’t tolerate oestrogen, which is contained in most oral contraceptives
• It is not affected by changes in body weight or when most other medications are being used – always to tell the doctor you are seeing that you are using Depo, and ask if any other drug that is prescribed will lower its effectiveness
• Depo does not affect a mother’s ability to breast feed and does not harm a breast-feeding infant. It is recommended women wait 3-6 weeks after giving birth before having the injection. This is to avoid confusion about any irregular bleeding because most birth-related bleeding should have stopped by this time.
What are the disadvantages of Depo?
• Once the injection has been given it cannot be removed or cancelled – it has to wear off
• Using Depo involves regular visits to see a doctor or nurse, which can be inconvenient/costly
• Some women experience side effects such as headaches, tiredness or mood changes
• Around 40% of women using Depo gain weight, but it is usually less than 2kg
• Some women experience a loss of libido (loss of interest in sex), though this can happen with any hormonal method of contraception
• Irregular bleeding may occur for the first few injections. This is usually light bleeding and for a few days only. Prolonged heavy bleeding is uncommon
• Long term use of Depo reduces the mineral content of bone in some women, which can lead to osteoporosis
Depo does not protect you from sexually transmissible infections (STIs).
Will it affect fertility in the long term?
The return of fertility is often delayed by approximately 5-6 months, but the effect of Depo on fertility is temporary. Studies have shown no evidence of any effect on future pregnancies.
Does Depo have long term side-effects?
To date no studies have demonstrated any long term side-effects. Recent reports suggest that women who are at risk of developing osteoporosis need to be monitored closely, maintain a calcium-rich diet and do regular weight bearing exercise (low impact aerobics, weight training, walking or running). Smoking has also been shown to increase the risk of osteoporosis.
The loss of long-term bone density related to long-term use of Depo appears to be reversed when injections are stopped.
Practising safe sex reduces the risk of contracting HIV
and other sexually transmissible infections (STIs)
Page last updated Fri, 11 Jul 2008 16:27