To overdose on caffeine, you'd probably have to drink around 75 8oz cups of brewed coffee over the course of just a few hours. The effects vary from person to person, but that's a good estimate for a toxic dose. On the other hand, it doesn't take much caffeine at all to start experiencing negative side-effects, like heart palpitations or mood swings. A review of 200 studies suggests that a safe dose for an adult is only about 3 8oz cups.

  • Promethean Sky

    3 cups? In my family that will barely get you alert enough to make another pot.

    • GawainLavers

      Huh…I consider myself a lightweight because after 1 mug I’m good, but two mugs and I’m too hyper to focus.  But those are 24oz mugs.

    • Antinous / Moderator

      A cup of tea is enough to kick me into SVT.

  • s2redux

    Futurama did this research in 2003 (or maybe it was 3003). One not-unexpected finding: 100 cups puts you into bullet-time.

  • nmcvaugh

    But if you can push through that 75 cup barrier:

    http://www.youtube.com/watch?v=gILlaMTuOt4

    You will be able to transcend time itself:

    http://www.youtube.com/watch?v=C9Ef0ErCU1c

    Or so I’ve seen on TV.

    • s2redux

      You owe me a Coke! <g>

  • Rich Keller

    I’m trying to cut down on my jitter candy intake.

    • Wreckrob8

      I just treat myself to a couple of quadruple espressos on a Sunday now. I don’t miss my daily dose at all.

  • Wreckrob8

    8oz cups? How unamerican!

  • theophrastvs

    chocolatecoveredespressobeans!!! [zig-zat...]

    • http://www.gyrofrog.com/ Gyrofrog

       aka Buzzballs

  • http://www.facebook.com/postelwait Cameron Postelwait

    yeah but it takes at least 6 cups a day to counter-balance my heroin habit.

  • http://twitter.com/Neowolf2 Neowolf

    Probably depends on whether you have the fast metabolizer version of CYP1A2.

  • Thomas Schmidt

    Coffee must be like Iocane… I have developed an immunity to large doses :-)

  • dioptase

    I did these calculations about 9 years ago. Forgive the cut and paste.

    Caffeine LD50 (50/50 chance of killing you) is 150 mg/kg.
    Half life of 5-7 hours with extremes of 3 to 20 hours common.

    Coffee has 93 to 164 mg/5oz serving.

    I’m a big guy, 100kg, so could stand 15g before having a better than even chance of dying. Drinking 100 cups of the hard stuff at once would be a bad idea (16.4 g).

    But drink a cup of the hard stuff every 14.4 minutes and it never goes over 6.4 g (assuming a 7 hour half life).

    Now try some small woman, say 45 kg. Her limit is 6.75 gm. Might be ok or a risk, less than 50%, of dying. But if she’s on the pill, her metabolism half life is 13 hours. She hits exceed 9.3 g. Well above LD50 so probably a goner.

    Your mileage may vary.

    References:

    http://codeine.50g.com/other/caffeine.html
    http://www.chinamist.com/knowledge/health/caffeine /content.htm
    http://www.erowid.org/chemicals/caffeine/caffeine_ effects.shtm

  • adonai

    75 cups?