couple walking holding coffee cups
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Why Does It Matter?

Caffeine can affect you in many ways. It can:

  • Boost energy, memory, and athletic performance
  • Ease headaches
  • Help prevent constipation and type 2 diabetes
  • Protect against brain diseases like Parkinson’s and Alzheimer’s

But too much can make you anxious, nervous, or jittery. It can affect sleep, digestion, blood pressure, heart rate, and heart rhythm. And it can damage a child's developing heart, blood vessels, and nervous system.

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green tea
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Green Tea

Serving size: 8 ounces

Caffeine: About 28 milligrams

Some people think this is an herbal tea with no caffeine. It’s actually made from the same leaves as black tea (the Camellia sinensis bush). It generally does have a bit less caffeine.

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cup of hot tea
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Black Tea

Serving size: 8 ounces

Caffeine: About 47 milligrams

Skip your regular morning coffee and you may get groggy, tired, irritable, and even sick. If you want to cut back, do it slowly. That'll give your body a chance to get used to it. A cup of tea in the morning instead of coffee may be a good place to start. At most, tea usually has half the caffeine of coffee.

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sweet tea
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Iced Tea

Serving size: 8 ounces

Caffeine: 25-48 milligrams

The size here is the same as the other teas. But keep in mind that it’s often sold in larger -- sometimes much larger -- servings. That could mean more than 100 milligrams of caffeine. 

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brewsing coffee
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Brewed Coffee

Serving size: 8 ounces

Caffeine: 96 milligrams

For some retailers, 12 ounces is their smallest size. You can cut down how much caffeine you have by sticking to 8 ounces. Pour some out, if necessary. Of course, the stronger you make your coffee, the more caffeine it has.

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cup of coffee
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Serving size: 2 ounces

Caffeine: About 126 milligrams

Many espresso-based drinks at your local coffee shop (cappuccinos, lattes, macchiatos) use this 2-ounce “double shot” as a base. A 1-ounce “single” shot would have about half that (about 63 milligrams).

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coffee pot
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Decaf Coffee

Serving size: 8 ounces

Caffeine: 2-15 milligrams

There are different methods for getting rid of caffeine in tea and coffee. The amount left depends on what you start with and how you get rid of it. U.S. government regulations require 97% of caffeine to be removed from coffee to call it “decaffeinated.”

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Serving size: 12 ounces

Caffeine: 34-54 milligrams

This range is for both diet and regular sodas that have caffeine. Usually, those that have none have “caffeine-free” on their label.   

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drink can
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Energy Drinks

Serving size: 16 ounces

Caffeine: 140 to 350 milligrams

Ingredients like guarana can hide extra caffeine. The sugar or artificial sweeteners can make it easy to drink too much.

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gum in hand
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Caffeinated Gum

Serving size: 1 piece

Caffeine: 20-100 milligrams

It’s a good idea to do your homework on this. The range can be large and, like energy drinks, there can be hidden caffeine in ingredients like guarana. After meeting with the FDA, Wrigley, a major U.S. gum maker, decided not to sell gum with caffeine because of health concerns.  

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dark chocolate squares
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Dark Chocolate

Serving Size: 1 ounce

Caffeine: About 23 milligrams

Because caffeine occurs naturally in chocolate, the FDA doesn't require makers to list how much it has, so it's tough to know. It’s not too much if you stick to one serving, which is about a third of a typical dark chocolate bar. More than that and the numbers can start to add up.

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pills from bottle
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Over-the-Counter Pain Relievers

Dose: 2 tablets

Caffeine: 130 milligrams

Some of these combine aspirin, acetaminophen, or both with caffeine. Though they can work well on your headache, they also add to your total daily amount, so you may need to cut back elsewhere.

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white powder
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Powdered Caffeine

Dose: Not recommended at any dose

Caffeine: 1 teaspoon = about 28 cups of coffee

The FDA knows of at least two deaths from this stuff and recommends you avoid it. You can’t measure safe amounts accurately with typical kitchen equipment. See a doctor if you think you've taken too much, start to vomit, or notice your heart beating too quickly or in an odd rhythm.

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woman sipping coffee
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How Much Is Too Much?

Different people can handle different amounts. But there's a limit to what you should have every day, even if it doesn’t bother you. Up to about 400 milligrams a day is usually OK for adults as part of a healthy diet. Once you hit 600 a day, you’re probably getting too much.

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Sources | Medically Reviewed on 11/13/2019 Reviewed by Christine Mikstas, RD, LD on November 13, 2019


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Consumer Reports: “Caffeine levels in drinks, snacks, and drugs,” “Is Decaffeinated Coffee Bad for You?” “Is There More Caffeine in Espresso Than in Coffee?” “Are You Getting Too Much Caffeine?” “The Buzz on Death Wish Coffee.”


Indiana University Bloomington: “IU study finds caffeine boosts enzyme that could protect against dementia.”

Journal of Caffeine Research: “Caffeine Withdrawal and Dependence: A Convenience Survey Among Addiction Professionals,” “Caffeine Content Labeling: A Missed Opportunity for Promoting Personal and Public Health.”

Mayo Clinic: “Caffeine: How much is too much?” “Caffeine content for coffee, tea, soda and more.”

National Center for Complementary and Integrative Health: “Energy Drinks.”

FDA: “FDA Consumer Advice on Pure Powdered Caffeine,” “Caffeine Intake By The U.S. Population,” “Added Caffeine in Gum.”

USDA: "Basic Report: 14210, Beverages, coffee, brewed, espresso, restaurant-prepared," "Basic Report:  19904, Chocolate, dark, 70-85% cacao solids," "Basic Report:  14355, Beverages, tea, black, brewed, prepared with tap water," "Basic Report:  14278, Beverages, tea, green, brewed, regular."

Reviewed by Christine Mikstas, RD, LD on November 13, 2019

This tool does not provide medical advice. See additional information.

THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional medical advice, diagnosis or treatment and should not be relied on to make decisions about your health. Never ignore professional medical advice in seeking treatment because of something you have read on the WebMD Site. If you think you may have a medical emergency, immediately call your doctor or dial 911.