Pearl powder, which has recently made a comeback, dates back to AD 320. Made, as its name suggests, from crushed pearls, it was originally used in traditional Chinese medicine to treat a wide variety of ailments before becoming a popular skin whitener. China’s only female ruler, Empress Wu Zetian (AD 625–705), regularly took pearl powder internally, and used pearl cream on her skin for its brightening and beautifying properties. When she ascended the throne at the grand age of sixty-five, her beauty was legendary and her skin rumored to be “as radiant as a young woman’s.” According to the Bencao gangmu (Compendium of Materia Medica), an ancient Chinese medical text, pearl could stimulate new skin growth and healing, as well as reduce sun damage and age spots. Recent scientific studies have confirmed this, uncovering that pearl powder can actually stimulate the skin’s fibroblasts, help to regenerate collagen, and generally improve radiance.5 It Takes an Army Emperor Nero’s second wife, Poppaea, maintained an elaborate beauty routine that reputedly required a hundred slaves to be carried out. To keep Poppaea’s skin bright, her maids applied a daily face mask of moistened meal, in which she slept. Each morning the hardened crust of flour was washed away with ass’s milk. Poppaea also bathed regularly in ass’s milk, for its skin-lightening and softening properties, before applying a layer of chalk and white lead to her skin. Further applications of meal paste mixed with lemon juice were used to bleach her freckles. There’s plenty of scientific evidence for milk baths, as milk contains lactic acid, known to be an effective exfoliant, though white lead obviously would have been toxic. A version of this skincare routine soon became popular with most Roman women wealthy enough to afford the ingredients, and the slaves that were needed to prepare it.4 A bust of Emperor Nero’s second wife, Poppaea Sabina (AD 54-68).