A study, published online in The Lancet, in which 450 people underwent simulated jet lag in a sleep laboratory, found that the tasimelteon (Vanda Pharmaceuticals) group slept thirty minutes longer than the placebo group. Tasimelteon activates the receptors, which process a hormone produced at night that regulates the sleep cycle, like melatonin. Unclear is if the new drug is more effective than melatonin, because they have not been compared in a clinical trial.