A study explaining why mouse hairs turn gray made global headlines. Not because the little critters are in desperate need of a makeover; but knowing the “why” in mice could lead to a cure for graying locks in humans. Nowadays, everyone seems to be chasing after youth, either to keep it, find it, or just remember it.

People in the ancient world often turned to lotions and potions that promised to give at least the appearance of eternal youth. Roman recipes for banishing wrinkles included ingredients from donkey’s milk, swan’s fat, and bean paste to frankincense and myrrh.

Some ancient elixirs were highly toxic. China’s first emperor Qin Shi Huang, who lived in the Third Century B.C., is believed to have died from mercury poisoning after drinking elixirs meant to make him immortal. In 16th-century France, Diane de Poitiers, the mistress of King Henry II, was famous for looking the same age as her lover despite being 20 years older. A study of Diane’s remains found that her hair contained extremely high levels of gold, likely due to daily sips of a youth-potion containing gold chloride, diethyl ether, and mercury. The toxic combination would have destroyed her internal organs.

Many people in our world today are still trying to find ways to look younger forever.