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Evident owns Sleep Karma. Here's how we score every brand, including our own.

Energy

How Much Caffeine Is Too Much?

✓ Updated October 15, 2026
Four cups of coffee lined up in a row

The numbers

  • Most healthy adults: up to 400 mg/day is not generally associated with negative effects. That's about two to three 12 oz cups of coffee (FDA).
  • Teens: pediatric guidance cited by NBC News says adolescents should have 100 mg/day or less, or none (NBC News). Medical experts advise against energy drinks for children and teens (FDA).
  • Pregnancy, breastfeeding, some medications or conditions: talk to your clinician (FDA).
  • Danger zone: rapid intake of around 1,200 mg can cause toxic effects such as seizures (FDA).

What 400 mg looks like

SourceCaffeineServings ≈ 400 mg
Brewed coffee, 8 oz96 mg (Mayo)~4
Red Bull, 8.4 oz80 mg (Red Bull)5
Celsius, can200 mg (Celsius)2
100 mg caffeine pouch100 mg4
100 mg energy gum piece100 mg4

Signs you've had too much

Fast heart rate, palpitations, high blood pressure, insomnia, anxiety, jitters, upset stomach, nausea, headache (FDA).