The results in 2002 of a large U.S. study on hormone replacement therapy (HRT) in many respects left women confused and alarmed about the treatment for the menopause.
At that time the Women's Health Initiative (WHI) study indicated that women taking Prempro, a popular combination of synthetic estrogen and progesterone, increased their risk of heart attacks and breast cancer, while decreasing the chance of colon cancer and bone fractures.
It advised that postmenopausal women should not take hormones for disease prevention, as opposed to relief from menopausal symptoms, because the risks outweighed the benefits.
However the same was not true for women who had undergone a hysterectomy as they were found to have significantly increased rates of stroke and blood clots, but a lower risk of breast cancer and hip fracture.
Overall the lingering impression was that HRT was essentially not a good thing, even though the total number of hormone-therapy users affected by the risks or benefits were small.
The average age for menopause in the U.S. is 51, but for the vast majority of women it occurs between 44 and 56.
Around 1 percent of women experience a 'perimenopause' before age 40 when menstrual periods start to become irregular and ends one year after they stop altogether.
Perimenopause, which for the average woman starts at age 46, usually lasts from two to eight years.
For the average woman, fertility begins to decline around age 37, but women who don't want to get pregnant should continue to use contraception until they are definitely postmenopausal.
Scientists now know that it is the fluctuation in hormone levels which cause the hot flashes of the menopause which are more common in early postmenopause than in perimenopause, which eventually peter out.
Acne and thinning hair sometimes reflect hormonal changes, but can stop after hormone levels settle down.
However osteoporosis and vaginal thinning are more likely to get worse with age, unless women take estrogen.
Since 2002 hormone replacement therapy and its use has significantly changed and numerous remedies have hit the market, offering a range of treatments to treat the symptoms of menopause, which has left many women in a state of confusion and vulnerable to what is often unqualified advice.