Caffeine: How Much is Too Much?

What is caffeine?

Caffeine is a naturally occurring substance found in coffee, cacao, and guarana plants that can stimulate your nervous system. Like many people, you might enjoy starting your day with a cup of coffee for a caffeine boost. But, you may be surprised to find that caffeine is found in more than just your daily cup of joe.

Caffeine can also be found in tea, chocolate, and some soda drinks. If you’ve reached for an energy drink or supplement to boost your focus, you may have noticed that these rely on caffeine to do so. Some over-the-counter migraine medications contain caffeine because it helps to narrow blood vessels and reduce inflammation, which can help relieve pain. In skincare products, caffeine is often used to help brighten the skin or reduce the effects of aging.

Caffeine works as a stimulant by increasing activity in your brain and central nervous system. For many people, this can lead to a boost in energy and improved focus. But, for those who are sensitive to caffeine or consume too much, it can contribute to unpleasant feelings of jitteriness and difficulty sleeping. Too much caffeine can also have a detrimental effect on your heart health, irritate your stomach, and trigger or exacerbate symptoms of anxiety or panic.

While consuming a moderate amount of caffeine may have some health benefits, if you’re experiencing side effects from consuming too much caffeine, there are steps you can take to cut back, find healthier ways to boost your energy, and improve your overall well-being.

Recommended daily limits of caffeine

According to the United States Food and Drug Administration (FDA), the recommended daily limit of caffeine for adults is 400mg. This equates to about four to five 6-8-ounce cups of regular brewed coffee.

However, we all metabolize caffeine at a different rate and some people can be more sensitive to the effects of caffeine than others. You may have noticed that when you consume more caffeine than you normally do, you may experience unpleasant side effects such as anxiousness, jitteriness, headache, upset stomach, or difficulty sleeping.

The recommended daily caffeine intake can also vary according to age and other considerations:

Pregnant and breastfeeding women. The American College of Obstetrics and Gynecologists recommends that pregnant women limit their caffeine intake to no more than 200 mg of caffeine per day, which equates to about two 6 oz. cups of regular brewed coffee. This is to lower the risk for miscarriage or preterm birth. For women who are breastfeeding, the recommended limit is 300 mg per day, or about three 6oz. cups of coffee.

Adolescents. Caffeine may impact teens differently because they’re still developing physically and mentally. According to the American Academy of Pediatrics, adolescents over the age of 12 should limit their caffeine intake to 100 mg per day, which equals about one 6 oz. cup of regular brewed coffee or about two 12-ounce cans of soda. Some energy drinks contain two or three times that amount of caffeine in one serving. For more, read Caffeine and Its Effects on Teenagers.

Children under the age of 12. Currently, there are no safe guidelines for caffeine consumption for children under the age of 12. In fact, pediatricians recommend that kids under the age of 12 avoid all caffeine and energy drinks. This is because children are more sensitive to the effects of caffeine and sugar, and more research needs to be done about how caffeine can impact a child’s developing brain and body.

Caffeine limits for existing health conditions

If you have certain health conditions you may also want to limit the amount of caffeine you consume.

Anxiety and panic disorders. Caffeine can raise your heart rate and increase feelings of nervousness, which are similar to the sensations felt during an anxiety or panic attack. As a result, if you have an anxiety or panic disorder you may be more sensitive to the effects of caffeine and want to reduce your caffeine consumption.

Heart conditions. Caffeine can elevate your heart rate and may even cause an irregular heartbeat. If you have a heart condition, consult your doctor about how much caffeine is safe for you to consume.

Bleeding disorders. If you have a clotting disorder, caffeine consumption may decrease clotting and increase your risk of bleeding.

Glaucoma. Caffeine can increase the pressure in the eye for at least 90 minutes after consumption. If you have been diagnosed with glaucoma, ask your optometrist if it is safe for you to consume caffeine.

Gastrointestinal (GI) disorders. People who have GI disorders that can cause diarrhea, including irritable bowel syndrome (IBS), may want to limit caffeine intake during a flare up, as caffeine can worsen symptoms. Caffeine can also be an irritant if you have acid reflux or an ulcer.

Osteoporosis. Since high consumption of caffeine may increase bone loss, people who have osteoporosis or low bone density may want to limit their caffeine intake to no more than 300 mg per day, which is about three 6 oz. cups of regular brewed coffee.

Caffeine content of common products

Product	Caffeine content
8 ounces of brewed coffee	80-135 mg
2 ounces of espresso	100 mg
8-ounce latte	90 mg
8.2-ounce can of Redbull	80 mg
1 migraine relief medicine tablet	65 mg
8 ounces of iced tea	47 mg
8 ounces of brewed black tea	47 mg
1 can of Coca-Cola Classic	34 mg
1 cold relief medicine tablet	20 mg
1 ounce of dark chocolate	20 mg
8 ounces of green tea	15 mg
8 ounces of hot cocoa	14 mg
1 cup of chocolate ice cream	6 mg
1 ounce of milk chocolate	5.7 mg
8 ounces of brewed decaf coffee	2 mg

Benefits of caffeine intake

You might have noticed that caffeine can help you to feel alert and focused, but it can also offer some additional health benefits, when consumed at moderate levels. Some potential benefits of caffeine include:

Improved sports performance. Athletes often use caffeine before a workout, as the stimulant effect of caffeine may sharpen focus and improve endurance, increasing athletic performance. However, it’s not necessary to take too much. The effect is seen in doses of 200 mg, without additional side effects.

Reduced risk of neurological conditions. Some research has shown that consuming coffee regularly throughout your lifetime may contribute to a reduced risk of developing neurological conditions like Alzheimer’s disease or Parkinson’s. However, other studies have shown no such effect, and some that a high caffeine intake may even increase the risk.

Reduced risk of stroke. Studies have found that people who consume one cup of coffee per day may have a reduced risk of stroke. However, if you already have high blood pressure, drinking two cups of coffee per day could double your risk of stroke.

Reduced risk of type 2 diabetes. Although research is still needed to understand the mechanisms why, researchers have found that adults who consume coffee regularly had a reduced risk of developing type 2 diabetes. This may be because caffeine changes the way that your body processes glucose, or it may be due to another compound contained in the coffee plant, other than caffeine.

Improved liver health. Caffeine consumption appears to have a protective effect on the liver as people who consume caffeine regularly were found to have better liver enzyme levels when compared to individuals who don’t consume caffeine.

Lowered risk of gallstones. Some research has found that consuming caffeinated coffee may lower your risk of developing gallstones. Because this same effect was not found in individuals who drank decaffeinated coffee, the protective effect is thought to be due to caffeine.

Risks of caffeine intake

Although caffeine may offer some health benefits, consuming too much can lead to certain side effects—and even exacerbate certain health conditions.

Anxiety and jitteriness

Overconsumption of caffeine can lead to symptoms associated with anxiety, such as jitteriness, nervousness, and restlessness. Caffeine can also cause increased heart rate, which could trigger a panic attack.

Sleep disturbances and insomnia

Because caffeine is a stimulant and works to increase energy levels, it can impact your sleep, especially if consumed too close to bedtime. Caffeine decreases several hormones associated with quality sleep. Sleep experts suggest that you stop consuming caffeine at least six hours before the time you go to bed. Remember that caffeine isn’t just present in coffee, soda, and energy drinks, but also in tea and chocolate (including chocolate desserts).

Increased heart rate and blood pressure

Caffeine’s stimulant effects can cause your heart rate and blood pressure to increase. While many people don’t notice a difference, others can experience heart palpitations after consuming caffeine. If you already have high blood pressure and don’t regularly consume caffeine, caffeine may cause your blood pressure to spike even further.

Digestive issues

Caffeine acts as a diuretic, meaning that it may cause you to need more bathroom trips than usual. If you have a digestive disorder such as IBS, caffeine could make your symptoms worse. Caffeine can also relax the ring of muscle at the top of your stomach while increasing your stomach’s production of acid, which can cause stomach acid to move into the esophagus, resulting in acid reflux.

Thinning bones

Caffeine can interfere with how your body processes calcium, an important building block of bones, causing you to secrete more calcium than you might normally. Over time, this can weaken your bones, putting you at an increased risk of fractures. If you already have osteoporosis or thinning bones, you may need to be mindful of the amount of caffeine you consume.

Caffeine and medications

While caffeine is sometimes added to medications for treating migraines and colds, it can interact with other medications, including:

• Attention-deficit hyperactivity disorder (ADHD) medications. ADHD medications like Adderall and Ritalin are stimulants themselves, just like caffeine. This means that taking them together can result in symptoms such as anxiety, jitteriness, and increased heart rate.
• Birth control pills. Birth control pills, especially those containing estrogen, can impact the way that your body processes caffeine, meaning that you may feel more significant caffeine side effects or experience the effects of caffeine for longer.
• Blood thinners. Caffeine can interact with the way that your body processes blood thinners such as Warfarin. This can put you at an increased risk of bleeding.
• Antidepressants. Caffeine can impact how your body processes some selective serotonin reuptake inhibitors (SSRIs) like Luvox and Lexapro. If you consume large amounts of caffeine with these medications, you may experience symptoms like anxiety and jitteriness.
• Cold or allergy medications. Pseudoephedrine is found in newer cold and allergy medications that contain decongestants, like Sudafed and Dimetapp, and acts as a stimulant. This means that pairing this with caffeine can exacerbate caffeine side effects like shakiness and nervousness.
• Iron supplements. If you have anemia and are taking an iron supplement, it is important to be aware that caffeine can decrease the absorption of this supplement. Taking your iron supplement at a different time of day than when you consume caffeine may be a way to address this problem.

Caffeine and food

It’s generally safe to consume caffeine on an empty stomach. However, if you have a sensitive stomach, you may find that consuming caffeine with a meal can help to prevent GI issues.

It’s also important to be aware that drinking alcohol alongside caffeine (vodka and Red Bull, or rum and cola, for example) may cause you to consume more alcohol than normal, which in turn can have a negative impact on your overall health.

Signs of caffeine overconsumption

If you consume more than 400 mg of caffeine in a day or are someone who has a greater caffeine sensitivity, you may experience some signs of overconsumption. These signs typically begin within a half hour of caffeine consumption and can last up to 12 hours.

Physical signs of caffeine overconsumption include:

• Increased heart rate
• Difficulty sleeping
• Headaches
• Dizziness
• Shakiness and jitteriness
• Muscle tremors
• Dehydration

Psychological signs of caffeine overconsumption include:

• Anxiety and nervousness
• Agitation and restlessness
• Irritability

Caffeine tolerance and toxicity

If you regularly consume large amounts of caffeine, your body can build up a tolerance. This means that over time you may need to consume more and more to experience the same boost in energy or focus. Studies suggest that if you routinely overconsume caffeine, you may develop a dependency.

When consumed rapidly, 1200 mg of caffeine (less than ½ tsp of pure caffeine) can lead to caffeine toxicity. Although rare, caffeine toxicity can result in vomiting, irregular heartbeat, and even seizures.

Tips for reducing your caffeine consumption

Whether you’re looking to reduce your caffeine intake or cut it out of your diet altogether, it’s important to do so safely and avoid any caffeine withdrawal symptoms.

Caffeine withdrawal symptoms can include:

• Headache.
• Fatigue.
• Difficulty concentrating.
• A drop in mood.
• Flu-like symptoms.
• Caffeine cravings.

When withdrawal hits, you may find you need a caffeine “fix” just to help you feel normal again. You can often avoid withdrawal symptoms by cutting back on your caffeine consumption gradually, rather than abruptly stopping or drastically reducing your intake all at once.

Tip 1: Create a log to avoid caffeine withdrawal

Before you start cutting back, it’s important to get a true understanding of just how much caffeine you’re getting on a daily basis. Since caffeine is found in many different products, it can be easy to underestimate.

Consider all sources of caffeine in your diet, including tea, coffee, chocolate, and energy drinks. Ensure that you carefully read all labels, as some products can contain hidden caffeine. Two over-the-counter pain relievers, for example, could contain up to 130 mg of caffeine, more than a double espresso.

It’s also worth noting that some skincare products also contain caffeine. Caffeine can be absorbed through the skin and hair follicles, albeit quite slowly. While this may not have a significant effect on your overall daily caffeine consumption, it is wise to follow the manufacturer’s instructions when using these products.

How to create a log

• In a notepad or on your phone, you can keep track of every cup of coffee or other caffeinated product you consume.
• It’s also worth noting the time of day and how you were feeling before and after you reached for a coffee or an energy drink. The more detailed your notes, the better you’ll understand the effects of caffeine is having on your body and mind.
• There are also nutrition apps you can use that will help track your caffeine intake. Some will even help you estimate how much caffeine is in your homemade cups of coffee or tea.

Tip 2: Cut back on caffeine gradually

Once you have an understanding of how much caffeine you’re consuming daily, you can create a plan for reducing it gradually.

Drink less caffeine over a longer period. If you typically consume four cups of coffee a day, for example, you may want to try reducing it to three cups a day at first. To prevent any caffeine withdrawal symptoms, it may help to drink this reduced amount of coffee over a longer period to ensure you have a more steady intake of caffeine over the day.

Cut back on the caffeine content in your favorite drinks or foods. Another way to gradually reduce your caffeine intake is to reduce the amount of caffeine in what you’re already enjoying. For example, if you love getting a drink from a coffee shop on your way to work, you might start asking for it to be made half-caf.

If you typically drink tea, you can simply shorten the brewing time to reduce the caffeine content. Chocolate lovers might consider switching to chocolate with a lower concentration of cacao, which contains less caffeine.

Choose caffeine-free alternatives. Switching to an alternative free of caffeine can make it easier to consume less caffeine without losing something you enjoy. Coffee and tea drinkers might consider choosing a decaf variety. However, it’s important to note that decaf coffee and tea still often contain a small amount of caffeine.

Most herbal teas, though, are naturally caffeine-free, although check that they don’t contain yerba mate and guayasa, which do contain caffeine. If you enjoy drinking soda, you might consider switching to a caffeine-free alternative like flavored sparkling water instead.

Tip 3: Boost your energy and focus without caffeine

Many of us reach for caffeinated beverages to boost our energy and focus as it starts to flag during the day. However, there are other energy-boosting habits that can help you feel alert and productive without the need for caffeine.

Stay hydrated. Fatigue can be a common symptom of dehydration, so ensuring that you’re drinking enough water during the day can help fend off that mid-afternoon slump. Women need an estimated nine cups of water per day, men about 13 cups. As a bonus, staying hydrated can help to ward off symptoms of caffeine withdrawal, such as headaches.

Get moving. Exercise naturally increases endorphins and the neurotransmitter norepinephrine, which can help you feel more energized and focused. Incorporating movement into your day when you typically feel a slump, such as taking a walk on your lunch break, may help you sustain your energy throughout the day.

Fuel your body. Food is your body’s fuel source, so eating regularly can help maintain your energy levels without relying on caffeine. Opt for meals and snacks that contain a balance of complex carbs, lean protein, and healthy fats. Carbs can give you a quick boost of energy, whereas protein and fats digest more slowly to help you sustain that energy. An apple with peanut butter or whole-grain crackers with cheese are good energy-supporting snack options.

Create healthy sleep habits. Getting good quality sleep at night is important to help you avoid feelings of sluggishness during the day. Incorporating healthy sleep habits, such as avoiding screen time before bed and creating a restful sleeping environment, can help you get the quality sleep you need. You may also consider taking a short nap during the day. However, limit a nap to 20 minutes so you don’t find yourself feeling groggy.

Get outside. Nature can have a stress-relieving effect on your body, which can help you feel more energized. Exposure to sunlight can also boost your mood and help regulate your circadian rhythm, so you feel energized during the day and sleepy at night. If you choose to take a walk outside, you’ll also get the added benefit of mood-boosting endorphins.

Consider supplements. Deficiencies in iron, B vitamins, and vitamin D can contribute to feelings of fatigue. If you’re struggling with your energy levels, you may consider consulting your doctor or dietitian who can determine if you’re deficient in these nutrients and which dietary supplements may be most helpful to you.

Caffeine and wellness

Caffeine can have positive impacts on your health, such as improving your energy levels and focus. However, if you consume too much caffeine—or are more sensitive to its effects—you may experience unpleasant side effects such as headaches, dizziness, jitteriness, and anxiety.

Since caffeine is found in many different products beyond coffee and tea, it can be easy to underestimate the amount you’re consuming each day. If you’re consuming too much caffeine and it’s adversely impacting your physical or mental health, cutting back and adopting healthier habits to boost your energy can help you improve your overall well-being.

Last updated or reviewed on October 15, 2024