Social media users are slurping down the "sleepy girl mocktail" — a concoction they claim has cured agonizing nights of restlessness, sending even the worst insomniac into a serious slumber. Videos of TikTok stars mixing the drowsy drink — which consists of just half a cup of seltzer water, half a cup of tart cherry juice and a spoonful of magnesium powder — have collectively clocked up tens of millions of views on the app.