Oprah Winfrey's a fan - and many doctors say it's safer and more effective. But as millions of women switch to new 'bio-identical' hormone therapy, critics say it's all just flim flam.
When Ivana Daniell was in her mid-40s, she began to notice her body changing. 'I was becoming bloated and puffy and my energy was non-existent,' she says. Disheartening for any woman, but for Ivana it was serious; she runs a Pilates and body conditioning studio for athletes and for people needing rehabilitation after injury - and looking well and fit is essential to her livelihood.
The most likely explanation seemed to be that I was moving into the menopause,' she says. But this presented her with another problem.
'HRT was just not an option. After what had happened to me when I went on the Pill - nausea, headaches and a vanishing sex drive - there was no way I was going to start taking extra oestrogen in this form.'
That was ten years ago and now Ivana is a remarkably sleek and fit 55-year-old. And it's all thanks, she says, to a new form of HRT.
Not only is this new HRT said to be more effective in treating menopausal symptoms, but it's also said to be safer. It contains the same hormones found in regular hormone therapy, but they come in a subtly different form known as 'bio-identical' - which means they have been chemically manufactured to be the same as the ones your body was making until it reached the menopause.
Conventional HRT, on the other hand, uses hormones that are slightly different from the ones found in the body and are designed to achieve the same effect as the body's hormones. It sounds like a subtle difference, but, in fact, this is supposedly what makes bio-identicals safer and more effective.
Ten years ago, bio-identical hormones were offered only by a few specialised clinics around the world, as everyone believed conventional HRT to be safe and effective.