Table of ContentsView AllTable of ContentsDaily Caffeine AmountsSymptomsMedication InteractionsReducing Caffeine IntakeFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
Daily Caffeine Amounts
Symptoms
Medication Interactions
Reducing Caffeine Intake
Frequently Asked Questions
Caffeine can be part of a healthy diet for most people. However, too much may be dangerous for your health.
Generally speaking, the guidelines for how much caffeine is too much are as follows: Adults shouldn’t have more than 400 milligrams (mg) of caffeine, which is about four to five cups of coffee, per day.Children and teenagers should not have more than 2.5 mg of caffeine per kilograms (kg) of body weight.
According to one study, about 85% of the U.S. population has at least one caffeine-containing beverage per day, with an average of 165 milligrams of caffeine consumed daily.
This article discusses how much caffeine you should have in a day. It also covers the signs and symptoms when you overindulge in caffeine and how to reduce your intake.
Verywell / Theresa Chiechi
How Much Daily Caffeine Is Too Much?
According to the U.S. Food and Drug Administration, adults should not consume more than 400 milligrams (mg) of caffeine a day. This comes out to about four or five cups of coffee.
The FDA doesn’t have official guidelines for caffeine intake in children and adolescents. But the American Academy of Pediatrics recommends adolescents (ages 12 to 18) limit their intake to 100 mg per day and that children under 12 avoid caffeine altogether.
Some people are more sensitive to the effects of caffeine than others. If you experience symptoms of too much caffeine, then you should reduce your intake.
How Much Caffeine Is in This?Food and drinks can vary in the amount of caffeine they have. Here are approximate amounts per item:12 ounces (oz) of caffeinated soft drink:30-40 milligrams (mgs)8 ounces ofgreenor black tea: 30-50 milligrams8 ounces of coffee: 80-100 milligrams8 ounces of decaf coffee: 2-15 milligrams8 ounces of energy drink:40-250 milligrams1 ounces of dark chocolate: 12 milligramsThese are averages. Always read the label to make sure you aren’t consuming more caffeine than intended.
How Much Caffeine Is in This?
Food and drinks can vary in the amount of caffeine they have. Here are approximate amounts per item:12 ounces (oz) of caffeinated soft drink:30-40 milligrams (mgs)8 ounces ofgreenor black tea: 30-50 milligrams8 ounces of coffee: 80-100 milligrams8 ounces of decaf coffee: 2-15 milligrams8 ounces of energy drink:40-250 milligrams1 ounces of dark chocolate: 12 milligramsThese are averages. Always read the label to make sure you aren’t consuming more caffeine than intended.
Food and drinks can vary in the amount of caffeine they have. Here are approximate amounts per item:
These are averages. Always read the label to make sure you aren’t consuming more caffeine than intended.
Switching From Coffee to Caffeine Pills: Is It Worth It?
Symptoms of Too Much Caffeine
When caffeine intake exceeds a healthy amount, it may lead to side effects. Symptoms of too much caffeine include the following:
What Are the Signs of Caffeine Overdose?
Headache
Caffeine is a commonly used psychostimulant, meaning it’s a substance that stimulates thecentral nervous system. This is why many people drink coffee or caffeinated tea as a morning pick-me-up. In some cases, caffeine is used as a form of pain relief, such as in the pain medicine Excedrin, which contains aspirin, paracetamol, and caffeine. However, both consuming too much caffeine andwithdrawal from caffeinecan cause headaches.
Caffeine can trigger what is known as “caffeine rebound.” This means that after you drink a lot of caffeine, you may experience withdrawal symptoms after the initial benefits have worn off. Overall, the National Headache Foundation says that it’s fine to consume caffeine in moderation. However, it’s best to avoid daily use if you are experiencing frequent headaches.
Anxiety
Caffeine may affect your mood. While moderate caffeine intake can contribute to feelings of happiness, having two to six cups of caffeine can bring on anxiety.Anxietyis a feeling of being wound-up, restless, or on edge.
A review of 57 studies measured the effects of anxiety after consuming various amounts of caffeine. Results were mixed when it came to both low and high intakes. Some research showed having up to five cups of coffee had no effect on anxiety. Other studies found feelings of tension after consuming just two or three cups.
Whether you feel anxiety at low or high levels, it could indicate that you are having too much caffeine and may want to scale back.
Trouble Sleeping
When consumed close to bedtime, caffeine may cause mild sleep disturbances at moderate and high doses. Consuming caffeine before bed can reduce the quantity and quality of sleep and make it harder to fall and stay asleep. It is recommended to not have caffeine up to six hours before bed.
However, if you regularly consume caffeine, its effects won’t be as detrimental to your sleep over time. Your body can adjust to the effects of caffeine and build up a tolerance over time.
Irritability
Consuming caffeine can also contribute to feelings of irritability, but this has mostly been observed in people who consume a lot of it. However, if you have an existing psychological or anxiety disorder, you may experience irritability with less caffeine consumption than the average person.
Although more research needs to be done to find exactly how much caffeine leads to irritability, you may want to scale back if you get angry or agitated after consuming caffeine.
Increased Heartbeat
Caffeine has different effects on the heart. Some research found as little as four cups of coffee could cause mild changes in heart rate.Another small study found consuming five cups of coffee did not affect heart rate in people withheart disease.
This may be due to how well the body can break down caffeine. Slow caffeine metabolizers were more at risk for heart issues after just two or three cups of coffee. While those who cleared caffeine from their system quickly had fewer issues when consuming the same amount of caffeine.
A rapid heartbeat can also signify a caffeine allergy,sensitivity, or another health issue.Cutting back or eliminating caffeine is recommended if caffeine affects the heart.
Increased Thirst
Research shows even low intakes of caffeine may increase thirst in some people. Thirst was most notable to casual caffeine consumers even just after one cup of coffee. Those with daily caffeine intake were unable to detect thirst at this level.
There is no evidence of how high caffeine consumption affects thirst. However, it is possible that being thirsty could be due to high levels of caffeine.
Frequent Urination
Caffeine is adiuretic. This is a substance that increases the production of urine and makes you have to pee. Caffeine can increase blood flow to the kidneys and directly affects their ability to reabsorb salt and water as they filter the blood, leading to an increase in urine in the bladder.People with an overactive bladder may be more susceptible to the diuretic effect of caffeine.
Along with the loss of urine also goes important nutrients. One study found that having about four cups of coffee caused reductions in thiamin, B12, calcium, magnesium, sodium, phosphate, chloride, and potassium. This could have a negative effect on bone health.
While it is ultimately unknown how higher intakes of caffeine affect the bladder, the frequent need to pee could indicate too much caffeine or another condition.
Chest Pain
Chest pain occurs when blood flow to the heart is blocked. As caffeine increases, so do the restrictions in blood flow. Therefore, too much caffeine may cause chest pain.However, the caffeine needed to cause chest pain is generally a very high amount, so overall the risk is low if you are only consuming one to three cups a day.
Those with health conditions, who are on medications, and/or are caffeine sensitive may experience decreased blood flow and chest pains with less than two cups of coffee.If you have chest pains after consuming caffeine, it could indicate a serious problem. Be sure to seek medical help right away.
Allergic Response to CaffeineIf consuming caffeine results in problems breathing, you could have a caffeine allergy. If this happens, stop consuming it right away and seek medical help.Call 911 if you are experiencingsymptoms of anaphylaxis, including trouble breathing, hives, low blood pressure, and a pale skin color.
Allergic Response to Caffeine
If consuming caffeine results in problems breathing, you could have a caffeine allergy. If this happens, stop consuming it right away and seek medical help.Call 911 if you are experiencingsymptoms of anaphylaxis, including trouble breathing, hives, low blood pressure, and a pale skin color.
Caffeine and Medications
Ask your doctor how caffeine may interact with your medications so you can avoid absorption problems.
Caffeine Can Affect How Medications WorkCaffeine may increase or decrease how much medication is absorbed. This can alter the effects of the drug. Ask your healthcare provider to learn how caffeine may interfere with your medications.
Caffeine Can Affect How Medications Work
Caffeine may increase or decrease how much medication is absorbed. This can alter the effects of the drug. Ask your healthcare provider to learn how caffeine may interfere with your medications.
Tips to Reduce Caffeine Intake
Reduce caffeine intake with these tips:
How Long Does It Take For Caffeine to Wear Off?According to the FDA, caffeine has a half-life of about four to six hours. This means that up to six hours after you consume caffeine, at least half of the caffeine is still present in your body.
How Long Does It Take For Caffeine to Wear Off?
According to the FDA, caffeine has a half-life of about four to six hours. This means that up to six hours after you consume caffeine, at least half of the caffeine is still present in your body.
Summary
Caffeine is a natural stimulant that alters brain and body function. A majority of the population consumes at least one caffeinated beverage daily, mostly in the form of coffee, tea, and soda.
Moderate caffeine consumption has been associated with improvements in energy, mood, weight, cognition, and physical performance. However, too much caffeine may cause headaches, anxiety, trouble sleeping, irritability, respiratory issues, chest pain, thirst, and frequent urination.
Certain people may be more sensitive to caffeine and may see these effects at even lower doses. Caffeine may cause allergies, and alter the effects of certain medications.
If you find that caffeine leaves you with side effects you may want to limit or avoid caffeine altogether. Increasing your intake of water and nutrient and fiber-rich foods, such as vegetables, nuts, and seeds, may also help to reduce caffeine intake.
Frequently Asked QuestionsCaffeine levels vary depending on the size and type of coffee. An 8 ounce (oz) cup of brewed coffee has about 96 milligrams (mg) of caffeine.An 8 ounce cup of instant coffee has 62 milligrams of caffeine.A one-shot (1 ounce-1.75 ounces) cup of espresso contains between 63-110 milligrams of caffeine.Coffee cups range from 8-31 ounces. Bigger cups will contain more caffeine.An 8-ounce cup of green contains 30-50 milligrams of caffeine.Intakes over 400 milligrams of caffeine a day have been associated withinsomnia, jitters, anxiousness, a fast heartbeat, upset stomach, headache, and a sad mood.It may also increase the risk of male infertility, cancer, heart disease, mood disorders, and weakened bones.The way to eliminate caffeine is to wait it out. It takes about 3 to 6 hours for caffeine to leave the body.The only thing that can improve sleep is letting caffeine leave your system.If you arepregnant, trying to get pregnant, and/or are breastfeeding you should limit your caffeine intake to less than 200 milligrams a day (about one and a half 8-ounce cups).Doses between 1.4 and 2.7 milligrams per pound of bodyweight worked best when taken 60 minutes before exercise.No, there is still caffeine in decaffeinated coffee. An 8-ounce cup of decaf coffee has about 2-15 milligrams caffeine.
Caffeine levels vary depending on the size and type of coffee. An 8 ounce (oz) cup of brewed coffee has about 96 milligrams (mg) of caffeine.An 8 ounce cup of instant coffee has 62 milligrams of caffeine.A one-shot (1 ounce-1.75 ounces) cup of espresso contains between 63-110 milligrams of caffeine.Coffee cups range from 8-31 ounces. Bigger cups will contain more caffeine.
An 8-ounce cup of green contains 30-50 milligrams of caffeine.
Intakes over 400 milligrams of caffeine a day have been associated withinsomnia, jitters, anxiousness, a fast heartbeat, upset stomach, headache, and a sad mood.It may also increase the risk of male infertility, cancer, heart disease, mood disorders, and weakened bones.
The way to eliminate caffeine is to wait it out. It takes about 3 to 6 hours for caffeine to leave the body.
The only thing that can improve sleep is letting caffeine leave your system.
If you arepregnant, trying to get pregnant, and/or are breastfeeding you should limit your caffeine intake to less than 200 milligrams a day (about one and a half 8-ounce cups).
Doses between 1.4 and 2.7 milligrams per pound of bodyweight worked best when taken 60 minutes before exercise.
No, there is still caffeine in decaffeinated coffee. An 8-ounce cup of decaf coffee has about 2-15 milligrams caffeine.
Correction - June 12, 2023: This article was updated to correct guidelines for caffeine intake in children.
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