Caffeine is a psychoactive stimulant that decreases drowsiness. Withdrawal symptoms happen as the brain adjusts to functioning without caffeine. Luckily, withdrawal doesn’t often last long and symptoms may be relatively mild.

The duration of caffeine withdrawal symptoms vary from person to person, but caffeine withdrawal usually lasts at least 2 to 9 days.

Someone who abruptly stops caffeine intake after regular use will usually feel withdrawal effects between 12 and 24 hours after stopping. The peak of withdrawal effects usually occurs between 24 and 51 hours.

If you regularly consume caffeine, caffeine withdrawal will likely affect you at some point. The more caffeine you drink, generally the worse the withdrawal experience is.

Habitual consumption of even just one small cup of coffee per day can produce withdrawal symptoms.

Caffeine is a psychoactive stimulant that decreases drowsiness by blocking adenosine receptors. Adenosine is a neurotransmitter connected to the body’s sleep-wake processes. By blocking the receptors, caffeine can allow a person to experience a temporary, improved feeling of wakefulness.

Caffeine also boosts other hormones and neurotransmitters like adrenaline and dopamine, and reduces blood flow to the brain.

One 2014 study identified genes that affect a person’s response to caffeine metabolism. Researchers can use these genetic markers to predict the likelihood that someone is a heavy coffee user. This suggests that your coffee cravings may just be genetic!

The more caffeine consumed daily, the more intense withdrawal symptoms tend to be. Symptom duration varies but might end between 2 and 9 days.

Common caffeine withdrawal symptoms include:

  • anxiety
  • cognitive effects
  • fatigue
  • headaches
  • mood changes

Headaches

Headaches are often associated with caffeine withdrawal. Headaches happen because caffeine reduces your brain’s blood vessels. This constriction slows cerebral blood flow. When you cease caffeine consumption, the constricted blood vessels expand.

After you stop using caffeine, blood flow to the brain increases. Headaches are from the brain adjusting to the increase in blood flow. Once the brain has adapted, the withdrawal headaches will stop. Duration and severity of the withdrawal headaches vary.

Tiredness

Fatigue is another symptom of caffeine withdrawal. Caffeine improves energy and reduces drowsiness by blocking adenosine receptors. Adenosine is a neurotransmitter that can cause fatigue in some circumstances. Once caffeine is eliminated, many people feel tired and fatigued.

While fatigue can be frustrating, allowing your brain’s neurotransmitters to stabilize should lead to more sustainable energy in the long run. Caffeine is quickly absorbed into the bloodstream and excreted through urine. Tolerance increases with use. This can lead to frequent use and dependency, and therefore a worsening of withdrawal symptoms.

Mood changes

Negative cognitive and emotional effects can also be a consequence of caffeine withdrawal. Caffeine stimulates the release of hormones adrenaline, cortisol, and epinephrine. Caffeine also increases the levels of neurotransmitters dopamine and norepinephrine.

If you have developed a mental and physiological dependence on caffeine, you might experience feelings of anxiety, difficulty concentrating, and a depressed mood. This should only occur while your body is adjusting to the lack of caffeine.

Here are some tips if you want to decrease or quit caffeine:

  • Taper consumption instead of going cold turkey. If you are used to drinking coffee, try half-decaf half-regular and gradually wean yourself off.
  • Avoid sources of caffeine. Make sure you are not accidentally reintroducing caffeine. Check labels on packaged sodas, tonics, and teas, even packaged food.
  • Hydrate. Dehydration can make withdrawal symptoms worse.
  • Take a pain reliever. Take an over-the-counter pain reliever like ibuprofen, acetaminophen, or aspirin to help with withdrawal headaches.
  • Get plenty of sleep. You will probably feel tired when you stop consuming caffeine, so help combat this by getting at least 7 to 9 hours a night.
  • Boost energy in other ways. Try these tips to boost energy naturally.

The bad

Those who over-consume caffeine at toxic levels can display features of caffeine intoxication (also referred to “caffeinism”).

Symptoms of this form of intoxication can include:

The good

Benefits of caffeine may include:

Much of the data collected on caffeine is observational in nature. There have been few randomized, controlled studies.

In 2018, the U.S. Food and Drug Administration (FDA) acknowledged that for healthy adults, up to 400 mg of caffeine in a day, or up to about four cups of coffee, was not associated with dangerous effects.

Safe upper levels of caffeine use during pregnancy is a bit more complicated.

A 2020 review of studies shows that though some experts suggest that pregnant women can consume up to 300 mg per day, other studies have shown that doses of caffeine as low as 100 to 200 mg per day during pregnancy is associated with an increased risk of complications including miscarriage, fetal growth restriction, and low birth weight.

For this reason, it’s a good idea to limit caffeine intake during pregnancy and speak with your doctor for specific recommendations.

Even one cup of coffee daily can cause withdrawal symptoms. Keep in mind that a cup is 8 ounces, and many mugs and to-go cups hold up to 16 ounces or more.

Caffeine tolerance and the body’s response is slightly different for each person. It’s a good idea to discuss caffeine consumption with your doctor.

Check out our chart about the effects of caffeine to learn more about caffeine and how it affects the body.

Caffeine is thought to be the most frequently used psychoactive substance in the world. Coffee, the primary source of caffeine for adults, is the second most consumed beverage in America after water.

Caffeine functions as a central nervous system stimulant, and even a small amount used daily can cause withdrawal symptoms. These symptoms can result in caffeine dependency.

The severity and duration of caffeine withdrawal symptoms vary from person to person, and your genetic makeup can play a part in how much coffee you consume.