Why You Should Never Use Retinoids in the Morning
And 11 other crazy (but true!) facts that prove timing really is everything in your health and beauty routines
Why: "Cortisol is a hormone that helps promote alertness and reaches peak levels in the blood first thing in the morning," says Steven Miller, Ph.D. candidate in neuroscience at Uniformed Services University of the Health Sciences in Bethesda, Md. "These blood levels tend to drop after this -- around 9 a.m. -- and spike later in the day between noon and 1 p.m., and again at 5:30 and 6:30 p.m." Miller's research suggests that the best time to drink your (first) morning cup of coffee is in the time slot when your cortisol level first begins to drop to compensate for decreased alertness.
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