Here's How Much Caffeine You Can Safely Have Per Day

    TL;DR: Keep on caffeinating.

    Do you love caffeine but also fear it a little?

    Everyone give it up for science because a new study determined that healthy adults can drink 400mg of caffeine per day and be A-OK.

    The consensus: 400mg (or about four 8 oz. cups of coffee) is not associated with adverse effects in healthy individuals.

    In other words, it won't hurt you. Researchers also concluded that healthy pregnant women can safely consume 300mg of caffeine per day and that children and adolescents can safely consume 2.5mg of caffeine per kilogram of body weight per day (so a teen who is 100 lbs. can have about 115mg of caffeine).

    For context, here's the caffeine content in a bunch of popular drinks:

    • Panera single espresso: 73mg

    • Panera iced coffee (20 oz.): 210mg

    • Starbucks tall Pike Place (12 oz.): 235mg

    • Starbucks grande Pike Place (16 oz.): 310mg

    • Starbucks venti Pike Place (20 oz.): 410mg

    • Red Bull (8.4 oz. can): 83mg

    • 5-Hour Energy (1.9 oz.): 215mg

    • Lipton Black Tea (1 bag / 8 oz.): 55mg

    • Coca-Cola (12 oz. can): 34mg

    Up until now, a review of the effects of caffeine hadn't been done since 2003.

    So, 15 years later (during which time more than 10,000 caffeine-related papers were published), Myers and her team set out to follow up on those findings with a more systematic approach.

    So, if you consume more than 400mg per day, are you in for a world of hurt?

    In the meantime, if you're a healthy adult, keep on enjoying those four or so cups per day. (Or that one venti.)