How Much Caffeine Is Too Much? Here’s When to Cap Your Consumption

For many, drinking a morning cup of coffee is just as necessary as brushing your teeth. Need proof? According to recent research from the National Coffee Association, past-day coffee consumption is the highest its been in two decades, with American adults drinking nearly 465 million cups of coffee each day nationwide. That’s a lot of java—but does that necessarily mean we’re overdoing it? How much caffeine is too much in one day?

The answer can vary based on factors like individual tolerance and health status, but there are some expert guidelines to keep in mind before you have your morning cup (or cups) of joe. Here’s what you need to know.

How Much Caffeine Is Too Much In One Day?

While the answer varies from person to person, health experts and dietitians say consuming up to 400 milligrams (mg) of caffeine per day is generally safe for most adults. That’s equivalent to about four 8-ounce cups of coffee.

“According to the US Food and Drug Administration (FDA), caffeine can be part of a healthy diet for most healthy adults,” says Qianzhi Jiang, PhD, RDN, a registered dietitian in Natick, Massachusetts, and owner of The Nutrition Changer. 

Some forms of caffeine, such as coffee or tea, may even deliver health benefits. For instance, studies suggest that moderate coffee consumption can help protect your body against cell damage and oxidative stress; reduce risk of chronic diseases such as type 2 diabetes, Parkinson’s disease, Alzheimer’s disease, and liver diseases; and possibly improve heart health, cognitive function, and physical performance.

Keep in mind that experts generally recommend pregnant people or people trying to conceive limit their caffeine intake to 200 milligrams per day, while breastfeeding parents should stick to 300 milligrams per day or less. And children and teens should avoid drinks with caffeine and sugar, according to guidance from the American Academy of Pediatrics. Certain medications or health conditions may also affect your caffeine sensitivity, the FDA notes, so be sure to talk to your doctor if you have any questions.

What’s more, individual responses to caffeine vary, and excessive intake can lead to some not-great side effects. As with most things in life, moderation is key to caffeine consumption.

Caffeine Amounts In Popular Foods and Drinks

Here’s something that may surprise you: While coffee and tea are well-known sources of caffeine, many other foods and drinks also contain this stimulant in varying amounts. Understanding the caffeine content in popular foods and beverages can help you make the best choices and manage your caffeine intake effectively. 

To help keep you on track, here are some average caffeine content amounts in common foods and beverages, according to estimates from the FDA, the US Department of Agriculture (USDA), and Umo Callins, RDN, a sports dietitian and owner of Well Rooted Health and Nutrition in Oklahoma City.

What about decaffeinated coffees and teas? While decaf beverages contain far less caffeine than their caffeinated equilalents, they still retain some: An 8-ounce cup of decaf coffee contains about 2–15 milligrams of caffeine (compared to 80–100 milligrams in its regular counterpart), per the FDA.

Common Side Effects of Having Too Much Caffeine

What happens when you blow past the recommended daily caffeine intake? Here are some common side effects of drinking or eating too much caffeine, according to Ellen Landes, RDN, a registered dietitian based in St. Charles, Illinois, and owner of The Runner’s Dietitian. 

Understanding these symptoms can help clue you in to when you may want to cut back on your daily cups of coffee, tea, or otherwise. And as always, talk to your doctor if you have questions or concerns about how caffeine impacts you.

What Should You Do If You’ve Had Too Much Caffeine?

Caffeine is a stimulant, meaning it can make you feel more alert and energized, the FDA notes. If you find yourself more jittery than energized or more anxious than alert, here are a few things you can do: 

1. Hydrate 

Drinking water is key when you’ve had too much caffeine. Because caffeine is a mild diuretic, you’ll want to make sure you stay properly hydrated.

2. Rest and Relax 

If you’re feeling jittery, anxious, or experiencing disrupted sleep due to caffeine, finding a quiet, comfortable place to rest and relax can be beneficial. Deep breathing exercises, meditation, or simply lying down with your eyes closed can help calm your mind and body, Landes says.

3. Pause Your Caffeine Intake 

It may seem obvious, but it’s essential to avoid consuming any more caffeine until the effects have subsided. “Caffeine effects can be noticed within 45 minutes of consumption and may last for three to five hours,” Callins says—but remember, caffeine can stay in your system even after its more noticeable effects have waned. “Allowing the caffeine to clear your system naturally is recommended.”

This means temporarily avoiding coffee, tea, energy drinks, and other caffeinated beverages or foods. Continuing to consume caffeine will only prolong the symptoms and delay your return to baseline.

4. Go for a Walk

Moving your body with a gentle walk may help relieve some of that caffeine-induced energy, according to UW Medicine. Just make sure to stop if you notice a sudden spike in your heart rate.

Tips for Curbing Caffeine Consumption

Whether it’s that morning cup of coffee to kickstart the day or an afternoon energy drink to power through a workout, caffeine has become a staple in our daily routines. But if you find yourself dependent on caffeine or experiencing adverse effects, it may be time to consider cutting back. 

Of course, that might feel easier said than done. Reducing your caffeine intake may cause withdrawal syndrome, which can be seen even in people with short-term use of caffeine and an intake of as low as 100 milligrams per day, Jiang says. “Although caffeine withdrawal is not dangerous, it can be very unpleasant,” she explains. “You may experience headache, sleepiness, irritability, and a general feeling of lack of wellness.” 

Cutting back on caffeine gradually may help lessen these symptoms. Here’s how to do it effectively, Jiang says:

The Takeaway

Most experts agree that up to 400 milligrams of caffeine per day is generally safe for adults, which equates to about four 8-ounce cups of coffee. But that greenlit caffeine amount can change if you’re pregnant, breastfeeding, trying to conceive, take certain medications (such as anti-anxiety medications), or have certain health conditions (such as high blood pressure or heart disease). Be sure to talk with your doctor about any caffeine questions or concerns.

While moderate caffeine consumption may offer some health benefits, overindulgence can lead to issues such as sleep disturbances, stomach problems, increased heart rate, and anxiety. If you’re experiencing symptoms of caffeine overload, know that hydration, rest, reduced intake, and gentle movement may help. 

Cutting back on caffeine may involve substituting with low- or no-caffeine options, gradually decreasing intake, or adopting alternative methods for alertness like exercise or napping. By staying mindful of consumption, you can have your coffee and drink it too.

This content is for informational and educational purposes only and does not constitute individualized advice. It is not intended to replace professional medical evaluation, diagnosis, or treatment. Seek the advice of your physician for questions you may have regarding your health or a medical condition. If you are having a medical emergency, call your physician or 911 immediately.