<< Back to medical library
Hormone Replacement Therapy (HRT)
Hormone replacement therapy (HRT) is the use of synthetic oestrogen and/or progesterone to make up for the decline or lack of these natural hormones. HRT is most commonly used in cases of early menopause (before the age of 45) or when menopausal symptoms are severe.
Due to the risks associated with HRT the New Zealand Ministry of Health no longer recommends the use of HRT for the prevention of heart disease or stroke, or as a first line treatment for osteoporosis.
During menopause oestrogen and progesterone production is reduced. Menopausal symptoms, such as hot flushes, sweats, and vaginal dryness, can occur as the body adjusts to these hormonal changes. The risk of developing osteoporosis (bone thinning) also increases during menopause.
The duration of menopausal symptoms varies considerably between women. On average, symptoms last for around two years. Approximately 20% of women pass through the menopause without noticing any symptoms, whereas approximately 15% of women report severe symptoms. See our Menopause medical fact sheet for a full discussion of symptoms and other treatments.
HRT Delivery Methods and Regimens
HRT can be taken in the following ways:
- Tablets taken by mouth
- Skin patches
- Vaginal creams or pessaries
- By injection or as pellets implanted under the skin.
Not all delivery methods will be appropriate for all women. This should be discussed with the doctor or specialist who is prescribing the HRT.
Different regimens of HRT work in different ways and produce different effects. Some regimens mimic the menstrual cycle, so that monthly bleeding occurs.
Continuous combined oestrogen and progesterone leads to an absence of periods in most women. However this may take several months to achieve.
Women who have had a hysterectomy are likely to be prescribed oestrogen alone. Women who have a uterus are more likely to be prescribed a regimen that includes progesterone. This is to protect against cancer of the endometrium (the lining of the uterus).
Before prescribing HRT the doctor will take a full medical history. The doctor should be advised if the woman has a history of any of the following conditions as HRT may not be appropriate in these circumstances:
- Breast cancer
- Endometrial cancer
- Gallstones
- High blood pressure
- Previous blood clots
- Liver disease such as hepatitis
- Uterine fibroids
- Endometriosis
- Diabetes
- Previous heart attack.
(Return to top)
HRT Benefits and Risks / Side Effects
When considering HRT it is important to discuss the potential benefits and risks of the treatment with the doctor.
Benefits of HRT include:
- Providing relief from menopausal symptoms
- Reducing the incidence of osteoporosis related fractures
- Reducing the risk of bowel cancer.
Disadvantages of HRT include:
- Depending on the HRT regimen some women will have irregular bleeding
- Side effects such as breast tenderness, headaches, nausea or weight gain, and mood swings
- An increased risk of breast cancer
- An increased risk of gallstones
- An increased risk of endometrial cancer (for oestrogen only treatment)
- An increased risk of blood clot.
- An increased risk of heart disease
- An increased risk of stroke
- An increased risk of dementia.
The New Zealand Ministry of Health recommends that if HRT is prescribed, it should be used in the lowest possible dose for the shortest possible time. It further recommends that the need for continuing HRT treatment is reviewed with the doctor every six months.
For further information about menopause and HRT contact your GP or Practice Nurse.
The Family Planning Association runs menopause seminars for women covering all aspects of menopause including HRT and alternative therapies. Consult your telephone directory for local contact details.
Everybody (2003). Hormone replacement therapy. CMPMedica (NZ) Ltd. Auckland. http://www.everybody.co.nz/page-e0ac56f9-5704-458f-ba90-c665c8ebf1b1.aspx
Gulli, L. F. and Odle, T. G. (2006) Hormone Replacement Therapy. The Gale Encyclopedia of Medicine, Third Edition. Jacqueline L. Longe, Editor. Farmington Hills, MI. Thomson Gale.
Ministry of Health (2003). HRT (Hormone Replacement Therapy). Ministry of Health. Wellington. http://www.moh.govt.nz/moh.nsf/30ad137c772c883e4c25665c002c4198/540bbe548d9944a9cc256de100079d3a?OpenDocument
New Zealand Guidelines Group (2004) Hormone Replacement Therapy: Evidence-based Best Practice Guidelines. Pamphlet. New Zealand Guidelines Group.
Last Reviewed – 28/02/08
Go to our Medical Library Index Page to find information on other medical conditions.