Hormone replacement therapy (HRT) is a system of hormone replacement for treatment of perimenopausal symptoms using oestrogen and the synthetic form of progesterone, progestin. Oestrogen-progestin therapy is recommended for women who still have their uterus who choose to take oestrogen. Use of oestrogen without progestin carries significant risks of endometrial cancer, because oestrogen and progesterone oppose each other, causing an equalisation process. Taking both hormones at once eliminates the increased risk.
Oestrogen and progestin combined pills/tablets
- Conjugated oestrogens/medroxyprogesterone under the brand names Premphase or Prempro (combined pill/tablet)
- Oestradiol/norethindrone under the brand name Activella (combined pill/tablet)
- Oestradiol/norethindrone acetate under brand CombiPatch – skin patch (transdermal)
- Medroxyprogesterone under brand name Provera (oral progestin in a pill or tablet + an oestrogen-only preparation)
- Micronised progesterone under brand name Prometrium (oral progestin in a pill or tablet + an oestrogen-only preparation)
- Norethindrone under brand names Micronor or Nor-QD ((oral progestin in a pill or tablet + an oestrogen-only preparation)
- Norethindrone acetate under brand name Aygestin (oral progestin in a pill or tablet + an oestrogen-only preparation)
- Levonorgestrel IUD under brand name Mirena (intrauterine device)
What does HRT do?
HRT bumps up your hormone levels (oestrogen, progestin) either temporarily, cyclically, or on an ongoing basis to combat the symptoms of menopause occurring, such as hot flushes and sleep issues. HRT can also help combat osteoporosis, since oestrogen helps keep calcium in bones.
HRT can be high or low dose. When progestin is combined with oestrogen, it protects against endometrial cancer. This type of cancer can develop with oestrogen-only therapy. If a woman does not have a uterus, HRT is not required. Monthly withdrawal bleeding may occur if progestin is used cyclically. Breakthrough bleeding is not a real period, but the result of hormone withdrawal on the endometrium.
What are the risks of HRT?
HRT does not come without risks, but the risk is usually offset by when you start hormone treatments and how long these treatments are used for. Short-term hormone therapy early in menopause is associated with less risks than starting later in menopause. Not all women have the same level of risk.
- May increase the risk of blood clots
- Heart disease
- Breast cancer
- Ovarian cancer
- Uterine (endometrial) cancer
- Urinary incontinence
Due to these risks, some recommendations are in place:
- Only use hormone treatments short-term for menopausal symptoms
- Use only the lowest effective dose for the shortest time possible (symptoms usually pass and disappear over time)
- Use osteoporosis prevention and treatment where applicable
- Long-term hormone therapy should only be used in women with a high risk of osteoporosis because the risk of bone loss is worse than other risks
- Consider all your options and compare risks and benefits
Do not use hormone therapy if you:
- Might be pregnant
- Have a personal history of breast, ovarian or certain endometrial cancers
- Have a personal history of pulmonary embolism, deep vein thrombosis, heart attack or stroke
- Have undiagnosed vaginal bleeding from unknown causes
- Have liver disease (though some liver-sparing oestrogens may be used, like the transdermal patch or vaginal creams)
How well does hormone therapy work?
There is plenty of evidence that increased oestrogen levels can reduce the severity and frequency of hot flushes, improve mood and sleep problems, and maintain the vaginal tissue. Increases in the collagen in skin and tissue have been observed. Osteoporosis is slowed, and tooth loss and gum disease risk can be reduced.
Side-effects of oestrogen-based hormone therapy
- Irregular vaginal bleeding
- Fluid retention
- Weight gain
- Tender breasts
- Skin pigmentation
- Possible worsening of endometriosis or uterine fibroids
- Skin irritation with transdermal patches
- Side-effects may abate after a few weeks of use
Side-effects of progestin-based hormone therapy
- Mood changes – anxiety, irritablity, depression
- Breast pain or tenderness
- Abdmonal pain or bloating
Cyclic progestin (taken 10-14 days per month) can cause PMS-like symptoms (bloating, cramping, breast tenderness, nausea, depression) and monthly withdrawal bleeding. Use of the Mirena hormonal IUD can alleviate some of the oral-progestin-based symptoms in some women.