How much

Can you overdose on caffeine?

By GyroscopeUpdated November 15, 20268 sources

From drinks it’s very hard. The FDA says toxic effects like seizures can come from taking about 1,200 mg of caffeine quickly. That’s about 13 cups of coffee drunk in one go, but it’s less than half a teaspoon of pure caffeine powder.

If someone may have had too much caffeine, call Poison Control at 1-800-222-1222. It’s free and confidential, and there’s an online tool at triage.webpoisoncontrol.org. Call 911 right away if the person collapses, has a seizure, has trouble breathing or can’t be woken up.

People worry about the third coffee of the day. The real risk sits in concentrated caffeine, where a dangerous dose fits on a spoon. Drinks dilute caffeine so much that the volume protects you, and powder takes that protection away.

We’d keep pure caffeine powder out of the house altogether. It’s too easy to misjudge, since the difference between a strong dose and a dangerous one is a small pile of white powder.

Why drinks rarely get there

The FDA’s warning is about taking it quickly. Spread over a day, the body clears some of each drink before the next one arrives. For healthy adults, the FDA’s daily figure is 400 mg (how much caffeine is too much?).

Signs of too much

The FDA lists a faster heart rate, palpitations, high blood pressure, trouble sleeping, anxiety, jitters, an upset stomach, nausea and headache. These are a reason to stop for the day.

AACAP’s 2026 sheet lists signs of a caffeine overdose in children and teens: vomiting, high blood pressure, a racing heart, heart rhythm problems, fainting, chest pain, seizures, confusion and hallucinations. Those are a reason to call Poison Control, or 911 for the serious ones above.

Who is more at risk

Children are, since a small body gets more caffeine per pound from the same dose, and pediatricians advise against routine caffeine under 12. So are people taking fluvoxamine, an antidepressant that took caffeine’s half-life from 5 hours to 31 in one study, which lets caffeine build up day after day (caffeine and antidepressants). And so is anyone using caffeine powder, where the dose is easy to get wrong. Pills and the strongest pouches are 200 mg each, so two of them come to 400 mg, the FDA’s figure for a whole day (are caffeine pills bad for you?, are caffeine pouches safe?).

Check your day

The how much is too much tool adds up your drinks against the line for your group. It never works out a toxic dose, since nobody should be aiming near one.