Everyone knows that coffee buzz that helps you get your day started but how long the buzz lasts depends on your ability to metabolize caffeine. “In 50 percent of people, caffeine has a half-life of two to three hours, which is why some of us can have a coffee after dinner and still sleep soundly that night,” says Jim Lane, PhD, professor of behavioral medicine at Duke University Medical Center, who studies caffeine.
“In others, caffeine’s effects last 6 to 10 hours, so even a cup of coffee after lunch can make it difficult for them to fall asleep.”
No matter how you metabolize the stuff, a morning joe gives most people the biggest jolt of the day. “By the time you pour your second cup, many of those receptors in the brain may be saturated with caffeine, so the effects aren’t as potent,” explains Jeffrey Mechanic, MC, president of the American Association of Clinical Endocrinologists.
Another reason to really savor your morning cup of coffee.