Miracle beauty products may be a staple Christmas present today, but they’re not a recent invention. Diane de Poitiers, a French noble woman and mistress of Henry II of France, tried to use gold to preserve her looks – in alchemical law, gold was immutable, and alchemists and apothecaries created various potions to pass this gift onto their customers. For Christmas, the BMJ has made a film about a French research team’s investigations of Diane’s remains, and its discovery that the gold she used to preserve her youth was actually slowly poisoning her. Lilley Mitchell stars as Diane.