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Does Caffeine Increase Cortisol? (According to Science)

Isaac Robertson
Published by Isaac Robertson
Fact checked by Donald Christman, BHSc FACT CHECKED
Last updated: May 4, 2023
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A morning cup of joe gives many of us that much-needed energy boost to start our day.

Although coffee is touted for its wide range of health benefits, there’s still plenty of controversy surrounding this substance, mainly because of its caffeine content.

To get the real deal on caffeine, we spent hours researching its effects on the body, including its impact on the hormone cortisol.

Here’s what we learned.

Quick Summary

  • Caffeine can increase the cortisol levels in the body, which hinder normal brain function, affect your heart rate, and also cause muscle breakdown.
  • Studies reveal that caffeine can affect your sleep, and alter several hormones.
  • High cortisol levels can also promote weight gain, fatigue, and promote stress.

Does Drinking Coffee Increase Cortisol Levels?

close up image of a woman's hand holding a white coffee mug

Drinking coffee can elevate your body’s level of cortisol only if it contains caffeine.

High cortisol levels can hinder brain function, cause muscle breakdown, and because it affects your heart rate, can lead to high blood pressure.

It’s also known to increase your risk for diabetes and alter the mood. And there are many in the general population who deal with stress!

On the other hand, low cortisol is a problem, too, as it can make you feel tired, anxious, and emotional.

Most people know cortisol as the stress hormone, but it isn’t all bad. It’s the main hormone from the adrenal gland that signals your body to be responsive and awake. It also helps decrease inflammation.

Many factors contribute to elevated levels of cortisol, but taking your caffeine in moderation is one great way to keep them in check so that you can make this work to your advantage.

Related: What Are The Best Supplements to Reduce Cortisol?

Effects Of Caffeine Consumption On The Body

man holding his temples in pain, and a woman wide awake at while laying down in bed

Caffeine stays in your system several hours after ingestion, with its half-life ranging from two hours to 12 hours, depending on individual differences in absorption and metabolism.

According to Steven E. Meredith, a postdoctoral research fellow at The Johns Hopkins University School of Medicine:

“Caffeine metabolism is slower among infants, pregnant women, and individuals with liver disease. In addition, some medications slow caffeine metabolism, which may increase the risk of caffeine intoxication. But the effects of caffeine also vary simply because we’re all different.”

Aside from a possible cortisol surge, here are other ways that this brain-stimulating drink can affect how you function.

Short Sleep

Having coffee can keep you up longer, thereby reducing the amount of sleep you get.

This also means that you spend less time in the restorative stages of sleep, which can impair your alertness even in the morning the following day. It will impact your overall health.

Alters The Effects Of Several Hormones

sad woman hugging her pillow

Besides cortisol, caffeine can alter the effects of several hormones, including the following:


Caffeine increases your dopamine levels and makes you feel good at first.

This substance is a drug because it can stimulate your central nervous system.

However, once that stimulation dies down, it can leave you feeling low—an effect that can create a physical dependence on caffeine.


Caffeine can hinder the absorption of adenosine, a neurotransmitter that tells your body that it’s tired. This stops adenosine from acting on your brain, making you feel alert for a time.


A drink of coffee shoots adrenaline into your system and gives you a temporary boost. However, it can make you feel fatigued, depressed and unable to deal with stress later.

Many people dealing with stress tend to counteract these effects with more caffeine, leaving them agitated throughout the day.

The Side Effects

person with a big fat belly trying to close his jeans

Weight Gain

Many experts believe that raised levels of cortisol can lead to stronger cravings for fat and carbohydrates, which can cause your body to store fat in the abdomen.

Abdominal fat carries far more health risks compared to other types of fat, so this is something you’d want to avoid.

Research also suggests that caffeine may diminish your ability to taste sweet flavors, thereby increasing your cravings for sugary treats [1].

The good news is that caffeine can boost your resting metabolic rate and help you burn about 30% more body fat, as long as you exercise after taking it [2].

Also, caffeine can keep your blood sugar levels raised, which will leave you feeling less hungry.


Caffeine gives cortisol and other hormones a temporary buzz, but it can leave you feeling fatigued once that buzz is gone. This is also when feelings of mild to moderate depression can set in, making physical activity more difficult.

On a positive note, caffeine has supported physical performance and endurance if not overused [3]. Combined with its fat-burning benefit, caffeine can enhance your workout and help you get in better shape if consumed properly.


Ingesting high amounts of coffee every day can lead to raised levels of cortisol, which can have undesirable consequences for your health, including chronic stress, weight gain, moodiness, elevated sugar that can cause health complications, and heart disease [4].

However, small to moderate amounts of this stimulant can improve your mood and provide the boost you need.

The Best Way To Drink Coffee

coffee mugs and coffee beans on a gray background

Caffeine carries potential positive and negative effects, and the only way you can truly enjoy its benefits is by taking it in controlled amounts.

Here are a few ways you can enjoy your coffee while minimizing its side effects.

Drink Coffee Before Exercise

The increased cortisol secretion from consuming caffeine can leave you feeling stressed. But if you reach for a mug of coffee in the morning before exercise, you’re likely to experience its performance-enhancing and fat-burning capabilities.

Related Articles:

Limit Your Caffeine Intake Levels

woman sipping coffee from a red mug

Having a nice, warm cup (or more) of joe surely feels great, but if you’re downing six cups or more daily, you’re setting yourself up for some long-term health complications.

But if you restrict your coffee consumption to four or fewer cups a day (which provides around 400 milligrams of caffeine) or take regular breaks from caffeine, you should be fine.

Mathew Woodburn-Simmonds, founder of Home Coffee Expert, shares that it still depends on the brew methods, coffee used, as well as one’s body composition.

He suggested drinking high-quality decaffeinated versions, especially for those who love coffee.

This way, one can enjoy the great taste of coffee without worrying about high caffeine intake.

If you’re an avid coffee drinker who consumes over six cups a day, removing the habit may bring withdrawal symptoms such as headache, tiredness, cravings, and muscle pain [5].

On another note, you can build tolerance to some of caffeine’s effects, including cortisol release.

If you only take the stimulant occasionally, it causes a significant bump in your cortisol.

But if you get a dose of caffeine daily by taking coffee, black and green teas, soft drinks, or eating dark chocolate, your body weakens its cortisol response [6].

You will still release cortisol, but not enough to wreak havoc on your system. For most people, this slight increase shouldn’t be a problem.

Time Your Coffee Intake

man sitting in a cafe looking at his watch while holding his phone

Since caffeine can stay in your system for eight hours or longer, you should limit your coffee consumption to the first part of the day to ensure you get a good night’s sleep.

After all, the best time to have coffee isn’t right after you wake up because cortisol peaks around waking hours, typically between 8:00 to 9:00 in the morning for most people.

So if you consume coffee within the first hour or two of waking, it becomes redundant because cortisol release is at its peak during this time.

Taking coffee during this time can also disturb your circadian rhythms and have other detrimental effects on your health.

Taking coffee during this time can also disturb your circadian rhythms and have other detrimental effects on your health.

Also, downing a cup of coffee when you don’t need it may diminish the effectiveness of caffeine stimulation. It can cause you to build caffeine tolerance faster, which means that the buzz you get from it will decrease.

Your cortisol will peak again between 12:00 p.m. to 1 p.m. and 5:30 p.m. to 6:30 p.m., but it isn’t recommended to take coffee after 2 in the afternoon for the reason stated above.

That said, it’s wise to have your first cup of coffee in the late morning when cortisol begins to decline, which happens around 9:30 to 11:00 in the morning.

But again, if you really can’t help it, you can take a cup of decaf in the afternoon.

Rob O. of coffee site Above Average Coffee, shares that at the end of the day, it is also important to notice and consider your personal response to caffeine intake so you can adjust your caffeine habits.


How Can I Reduce My Cortisol Levels Quickly?

You can reduce your cortisol levels quickly by eating healthy food - a balanced diet that includes bananas, pears, probiotics, green tea, and drinking plenty of water.

Sleeping well, practicing relaxation techniques, exploring a new hobby, listening to calming music, taking fish oil and ashwagandha supplements, and exercising have also been shown to help reduce measured cortisol levels.

What Foods Increase Cortisol Levels?

Foods that increase cortisol levels include coffee, trans fats, saturated fat from animals, refined sugar, alcohol, refined grains, and foods low in fiber.

Is Caffeine Bad for Your Adrenal Glands?

Caffeine is bad for your adrenal glands only if you consume too much.

High levels of caffeine in your system leads to poorly functioning adrenal glands that can damage the immune, neurological, cardiovascular, and endocrine systems.

The Bottom Line On Caffeine and Cortisol

Aside from helping you stay awake and alert, coffee has fat-burning and performance-enhancing capabilities that can benefit your overall health.

However, you must remember that it’s a drug; therefore, it should be treated as such.

That means taking it within the recommended dose will prevent over-stimulation, increased cortisol levels, physical dependence, and tolerance to its positive effects.

Enjoy your cup of java using the nifty guide above, and feel free to share your experiences by leaving a comment below.


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