Jennifer Rock, the Skin Nerd, picks her best dupes of her favourite celebrities.

One of my cardinal skin sins is buying a product simply because a celebrity has endorsed it. Celebrity endorsements make the beauty industry go round. The difficulty is deciphering which products are being touted for no good reason, and which are true mainstays in the stars’ regimes.

I believe that a celebrity actually likes a beauty product when a) I see the proof of a half-empty bottle or tube on their social media, or b) they say that it was recommended to them by a dermatologist or beauty editor.