Scientists are testing an extract of red clover as an alternative to hormone replacement therapy for symptoms of the menopause, such as hot flushes.
Red clover contains hormone-mimicking chemicals
The extract contains chemicals called isoflavones, which mimic the effects of the female sex hormone oestrogen.
A study will be carried out by Queen Charlotte's and Chelsea Hospital's menopause and PMS centre.
Use of HRT has declined in recent years following suggestions of an increased risk of stroke and breast cancer.
Guidance issued last year by the Royal College of Obstetricians and Gynaecologists concluded that HRT should only be used for short term relief of menopausal symptoms.
The Queen Charlotte team hope their work will provide women with an effective alternative.
Lead researcher Dr Chun Ng said: "We hope the product may help women with menopausal symptoms such as hot flushes, and also those with premenstrual syndrome.
"Problems such as hot flushes have a negative impact on quality of life, although many women simply suffer in silence.
"Since the scares about HRT, some patients are just not taking anything at all."
Red clover is used as a herbal remedy for respiratory problems, particularly whooping cough.
It is also marketed as a treatment for chronic skin conditions such as eczema and psoriasis.
The Queen Charlotte team will also test a second treatment, using low doses of a compound known as desvenlafaxine succinate, which is thought to stabilise the body's heat control mechanism.
Professor David Purdie, of the Centre for Metabolic Disease at Hull University, told the BBC News website, an alternative therapy would be useful for women who either could not or would not take oestrogen-based HRT.
However, he stressed that taking oestrogen was currently by far the best way to tackle menopausal symptoms.
"There is evidence that long-term use of combined oestrogen and progesterone therapy does carry a slight increased risk of breast cancer, although the risk is probably much less for oestrogen-only therapy," he said.
"This has to be put into context. We are talking about just a few cases per 1,000 women over five years.
"Women have to decide whether the better quality of life HRT can offer them outweighs the small increased risks."
Professor Purdie also said the effects of oestrogen-like substances taken from plants had been hyped up somewhat.
He said trials of their effect had to be tightly controlled as previous studies had shown that women with menopausal symptoms often responded positively to dummy treatments.