Most people came away from the World Economic Forum in Davos, Switzerland, last month fired up with financial and political fervour and ambition. I left with skincare inspiration. Davos in late January is heaving with the world's wealthiest, most innovative and influential people. And then there was me, fulfilling none of those criteria, but supporting the campaign group Menopause Mandate, of which I'm a co-founder, and celebrating the US publication of the new book I have written with Mariella Frostrup, Menopause Is Hot.

It all happened while listening to Monica Molenaar, the very youthful-looking co-founder of Alloy Women's Health, a major US telehealth business. As she talked about menopause support, I wondered idly how old she was. In her 30s, I presumed – young to be discussing menopausal matters so confidently. And yet to my astonishment, I later learned she is 51. How did she look so good? Not just wrinkle-free, but glowing….

In fact, Monica attributes her incredible complexion to a face cream containing a very small amount of estriol – a form of oestrogen. This is a skincare trend currently sweeping the States and, like anything from across the pond, it's manifesting over here too… but in rather a surprising form. Apparently, a number of women in the UK are using vaginal oestrogen on their faces. Yes, you read that correctly. They are using the topical HRT prescribed for menopausal symptoms down below on their facial skin.

I was aware of a couple of friends doing this, but staggeringly, it's more widespread than I thought. Women are using topical HRT prescribed for menopausal symptoms down below on their facial skin. Monica Molenaar, the very youthful-looking co-founder of Alloy Women's Health, released the Alloy M4 Estriol Face Cream. A decade ago, Monica discovered she had a BRCA gene, which increases the risk of breast and ovarian cancers, and had her ovaries surgically removed as a result. But that meant: 'I went straight into early menopause in my early 40s.'.

With menopause comes the reduction of oestrogen which can cause what's called 'genitourinary syndrome of menopause', a collection of symptoms that includes dryness, thinning skin, pain, increased UTIs and urinary incontinence. It can be treated – very successfully – with vaginal oestrogen, in the form of tablets, gels, creams or pessaries. Three years ago, Monica successfully used just that to treat her own urinary incontinence – and then wondered what would happen if she put it on her face. Clearly there was some logic behind this. Oestrogen is used 'down there' to plump up tissue and keep thinning at bay. Could it do the same higher up?.

Being in charge of a healthcare company meant she could experiment. 'Because the texture of vaginal oestrogen isn't ideal for facial skincare, we worked to create a product that combined the benefits of low-dose oestrogen with the luxurious consistency of a facial moisturiser, which is how our Alloy M4 Estriol Face Cream was born.'. The company commissioned a clinical study, which showed statistically significant improvements in skin condition after 12 weeks, and another showing there was no significant absorption of oestrogen into the bloodstream. (This was the hope – you want systemic HRT, such as oestrogen patches, to boost circulating levels, but not 'local' oestrogen to do the same.).

Available on their website ($149.97 or £120 for a three-month supply), via an online assessment and doctor's prescription, US doctors up and down the States are now recommending it. Indeed, every woman in the know is using it, from Fifth Avenue to the Hamptons, and skincare companies are leaping on the bandwagon and creating their own version. New York-based dermatologist Dr Ellen Gendler says: 'Adding low-dose topical oestrogen to your skincare routine can help combat the adverse effects decreasing oestrogen levels have on the skin. I recommend it to many of my patients.'.

Sadly, however, these creams aren't yet available in the UK. But there are plenty of women using (or misusing!), their own prescribed vaginal oestrogen instead. No, it doesn't feel like a high-end face cream, but the women who are doing this think that's a small price to pay for better skin. I first became aware of the DIY trend during a whispered conversation about HRT at a drinks party last year. I couldn't believe my ears when a friend confessed to using her tube of vaginal cream on her – admittedly excellent – skin. Since then, I've heard numerous tales of women dabbing their down under cream up top.

'The majority of women will experience some vaginal symptoms during or post-menopause, such as dryness, increased UTIs, pain during sex and urinary problems,' says menopause expert and founder of Menopause Care Dr Naomi Potter. Vaginal oestrogen contains a minute amount of the active ingredient, and when applied around the area it gives relief from sometimes agonising symptoms. 'Everyone should be offered vaginal oestrogen,' she adds. 'The tiny amount of oestrogen means that a very low dose is absorbed, so it's appropriate for women who don't wish to use or can't use systemic HRT – those who have had hormonal breast cancer, for example.'.