Caffeine increases brain activity, focus, and cognition while countering exhaustion. Common signs of a caffeine crash include headaches, tiredness, difficulty concentrating, and irritability. This can be caused by lack of sleep or drinking too much coffee.

Caffeine is the most widely consumed stimulant in the world (1).

It’s found naturally in the leaves, seeds, and fruits of several plants. Common sources include coffee and cocoa beans, kola nuts, and tea leaves.

It’s also produced synthetically and added to sodas, energy drinks, and certain dietary supplements intended to boost weight loss, energy, and focus.

While caffeine is known for its energizing effects, it can also cause a caffeine crash, characterized by increased fatigue and sleepiness.

This article explains what a caffeine crash is and provides 4 ways to avoid its energy-draining effects.

Caffeine stimulates your nervous system by increasing brain activity, thereby enhancing focus and cognition while delaying fatigue (2).

These effects can occur with low to moderate caffeine doses of 20–200 mg. They typically present within 60 minutes after consumption and last for 5 hours on average (1, 3).

After the stimulating effects wear off, it’s common to feel less alert or focused. However, experiencing extreme tiredness, an inability to concentrate, irritability, or a headache may indicate a caffeine crash or dependence (2).

A caffeine crash may result from a lack of sleep, consuming the substance too close to bedtime, or consuming too much. The symptoms range from mild to severe and last anywhere from hours to a week, depending on individual factors (1).

Fortunately, there are ways to prevent — or at least reduce — these productivity-killing effects.

Here are 4 tips to help you avoid a caffeine crash.


A caffeine crash can result due to poor sleep, consuming caffeine close to bedtime, or consuming too much. It’s associated with tiredness, the inability to concentrate, and irritability.

Many people turn to caffeine — whether from coffee, soda, or energy drinks — to increase alertness and promote wakefulness in the morning or throughout the day, especially after a poor night’s sleep.

Although achieving a good night’s rest may not be possible every night, it’s essential for preventing caffeine crashes.

Consuming caffeine when tired or energy-deprived will only temporarily relieve those feelings. Once the effects wear off, you may feel more tired than before.

In response, you may consume more of the substance. This pattern has been called the “coffee cycle,” and over time, it can lead to excessive use of caffeine (4).

The energizing effects of caffeine are stronger when you’re sleep deprived than when you’re well rested. As such, prioritizing sleep may be a way to eliminate or reduce your reliance on caffeine to keep you awake and alert, thus preventing caffeine crashes (5).

Regularly getting adequate sleep is not only effective for preventing caffeine crashes, but it’s also important for good health.

Long-term poor or inadequate sleep is linked with a higher risk of chronic illnesses like type 2 diabetes, heart disease, obesity, and dementia (6, 7).

Experts recommend sleeping 7–9 hours per night (8).


Regularly achieving adequate sleep can help decrease your reliance on caffeine for energy and prevent the crashes that may result from inadequate sleep.

Achieving adequate sleep can be difficult if you consume too much caffeine throughout the day or too close to bedtime.

Caffeine has an average half-life of about 5 hours, ranging from 1.5–10 hours depending on factors like age, overall health, whether you smoke, and genetics (2, 9).

In other words, half of the total amount of caffeine you consume remains in your body after approximately 5 hours. Thus, to avoid the substance affecting sleep, it’s generally recommended you avoid consuming it within 5–6 hours of bedtime (10).

In one study, participants who consumed a pill containing 400 mg of caffeine — equivalent to about four 8-ounce (240-mL) cups of coffee — 6 hours before bed experienced disrupted sleep and difficulty falling asleep resulting in 1 less hour of sleep (10, 11).

This disruption in sleep or difficulty falling asleep can increase sleepiness and fatigue the following day.

In fact, regular caffeine intake is associated with shorter sleep times, reduced sleep quality, and excessive daytime sleepiness (12, 13, 14, 15).

Depending on your tolerance to caffeine and when you usually go to bed, it may be best to only consume it early in the day (16).


Sticking to moderate amounts of caffeine early — rather than late — in the day can help you achieve a good night’s rest and reduce daytime sleepiness, which can otherwise result from consuming caffeine too close to bed.

Owing to caffeine’s long half-life, the more caffeine you consume throughout the day, the longer it will take to leave your body.

Consuming excess caffeine will not only lead to symptoms of a caffeine crash once it wears off, but it can also cause other mild to severe adverse effects.

Adverse effects of consuming too much caffeine include (1):

  • anxiety
  • agitation
  • elevated or irregular heart rate
  • stomach upset
  • restlessness
  • disorientation

While caffeine is commonly believed to cause dehydration, it only has a diuretic — or urine-producing — effect when consumed in excess and by non-habitual consumers (2).

When consumed in appropriate amounts, caffeine is safe for most people.

Studies suggest that healthy adults can safely consume up to 400 mg of caffeine per day, equivalent to about four 8-ounce (240-mL) cups of coffee (2, 17).

Since genetics also influence how fast someone metabolizes caffeine, a lower amount in some may be more appropriate.

It’s recommended that pregnant women consume no more than 300 mg of caffeine per day, with some studies recommending no more than 200 mg per day (2, 18, 19).

People with anxiety or gastroesophageal reflux disease (GERD) may want to limit or avoid caffeine altogether as it can worsen these conditions (20, 21).

Caffeine may also interact with certain prescription and over-the-counter medications. Therefore, it’s good practice to check with your physician or pharmacist to determine whether caffeine is appropriate and safe for you, and if so, in what dose (2, 22).


Consuming too much caffeine can cause agitation, an elevated or irregular heart rate, and stomach upset. Healthy adults shouldn’t exceed 400 mg of caffeine per day and pregnant women should consume no more than 200–300 mg per day.

If you regularly consume caffeine, you may have developed caffeine dependence.

Studies show that caffeine dependence can develop after just 3 days of use and from daily doses as low as 100 mg (23, 24).

Withdrawal symptoms resemble a caffeine crash and include headaches, decreased alertness, mood changes, and fatigue — all reversible by consuming caffeine.

Symptoms typically begin 8–12 hours from when you last consumed caffeine, peak after 1–2 days, and last for up to a week (23).

One of the first studies on caffeine withdrawal from the early 1990s demonstrated that regular caffeine users who abruptly stopped consuming caffeine experienced moderate to severe headaches, mood disturbances, and fatigue (25).

If you regularly consume caffeine and want to decrease or eliminate it from your diet, it’s best to decrease your intake slowly over several days to weeks rather than quitting cold turkey (1).

On the other hand, if you regularly consume caffeine and experience caffeine-crash symptoms from skipping your morning coffee or other caffeine-containing beverage of choice, simply consuming that beverage should improve the symptoms.


You can become dependent on caffeine even if only consuming it over a short period of time and in relatively small doses. You can avoid withdrawal symptoms by sticking with your usual caffeine intake or reducing your intake slowly over time.

A caffeine crash is characterized by symptoms like headaches, excessive tiredness, an inability to concentrate, and irritability.

You can avoid or reduce the severity of these symptoms by getting adequate sleep at night, avoiding caffeine too close to bedtime, and by consuming no more than 400 mg per day if you’re a healthy adult.

If you regularly consume caffeine, you can avoid crashes by sticking with your usual daily intake. Alternatively, if you wish to reduce or eliminate your intake, do so slowly rather than going cold turkey.