What can we say? We’re absolute suckers for a beauty secret. It gives us all sorts of unsolicited thrills to be in the know about a particular product that’s worth its weight in gold, with glowing benefits to our make-up bag or bathroom cabinet.

And an area that we never get tired of getting the scoop on is our complexions. So when we heard that Kate Middleton uses one very special facial product, we could feel ourselves itching to jump straight on the bandwagon – especially when we discovered that said product is so overwhelmingly popular that a bottle sells every 20 seconds.

Read more: This is the £4.49 highlighter that's been selling out all summer long

Of course, a royal lifestyle probably doesn’t hurt in preserving Middleton’s luminous skin. But according to InStyle, rosehip oil is the mystery ingredient lurking in the Duchess of Cambridge’s make-up bag.

Argan and coconut oils have been praised for their beauty benefits, and rosehip is the next big thing to add to your skincare routine. Pressed from the fruit of the rose plant, it’s rich in antioxidants like vitamins A, C, and E which means it plumps up your skin and soothes redness.

But it’s not just any old oil that Middleton uses (well, she is a royal). Her favourite is apparently Trilogy’s Certified Organic Rosehip Oil. Priced at £34.50 for 45ml on their website, you can also pick up a 20ml bottle of the golden liquid from your local Holland and Barrett for £19.99.

It’s said that Middleton was particularly fond of using the oil during her last pregnancy, as it’s known for working wonders on stretch marks. According to Trilogy themselves, “Rosehip oil's potent natural actives make it highly effective for scars and stretch marks and other skin concerns including dehydrated and ageing skin.”

The brand has even consulted independent clinical studies to prove that their blend of “finest quality” oil improves the appearance of scars, stretchmarks, fine lines and wrinkles. In fact, in their survey 43% of women confirmed the product, which contains 80% essential fatty acids, minimised stretchmarks.

We don’t know about you, but we’re sold – and so it seems, is everyone else.

Not only is a bottle whipped off the shelves every 20 seconds, but the Twittersphere also seems to be only too keen to pay testament to Trilogy’s rose-scented beauty buy.

And if it’s good enough for Middleton, it’s good enough for us. Be right back – we’re off to treat ourselves.

Images: Rex Features