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.

This beauty product sells every 20 seconds (and is a favourite of Kate Middleton)