The FDA puts the healthy-adult ceiling at 400 mg a day - about four cups of coffee - with 200 mg in pregnancy. Jitters, poor sleep, and a racing heart mean your personal limit is lower.
What to do
Common questions
How much caffeine is too much?
The FDA's working number: 400 milligrams of caffeine a day is not generally associated with negative effects for healthy adults - roughly four 8-ounce cups of brewed coffee, or two strong energy drinks. But that is a population average, and personal sensitivity varies widely: some people sleep fine on espresso at dinner, others are wired from one morning tea. Genetics, body size, medications, pregnancy, and tolerance all shift your real limit. Signs you are over yours: jitters, racing heart, anxiety, stomach upset, headache, and - most reliably - poor sleep. Caffeine's half-life is 4 to 6 hours, so a 4 PM coffee is still half-active at 10 PM. Pregnant women should cap at 200 mg, and kids and teens should minimize caffeine entirely. The serious danger zone is concentrated products: the FDA warns that one teaspoon of pure powdered caffeine equals about 28 cups of coffee and has caused deaths. Energy drink cans vary wildly - 80 to 300 mg - so read labels. And quitting cold turkey after heavy use causes real withdrawal headaches for a day or two; taper instead. Pymander is a free AI doctor, 24/7 by text. Tell it your daily caffeine habits, and it can help you count and adjust.