Why Does Caffeine Make Me Tired?

Roasted coffee beans

We love coffee. In fact, in case you hadn’t guessed, we’re actually quite passionate about it. But sometimes you have to recognize that even good things have weird side effects. There's one side effect of coffee that we get asked about relatively often. So, today, we're going to tackle it head one and answer the question "Why does coffee make me tired?"

Reason 1. Caffeine affects your stress hormones.

Coffee has a lot of caffeine, obviously. But did you know caffeine actually increases the stress hormone, cortisol, in our bodies? That extra bump in cortisol puts your body in fight-or-flight, heightening your feelings and awareness. Once your body metabolizes the caffeine, you'll go back to normal levels of cortisol and feel that caffeine crash.

Reason 2. Caffeine blocks the effects of Adenosine (aka what makes you feel sleepy).

If you've never heard of Adenosine before, no worries. Basically, Adenosine acts as a neurotransmitter in your body, telling the brain when to feel tired. Every morning, your Adenosine levels are at their lowest. As the day goes on, they steadily increase, until you go to bed. 

When you drink your morning cup of coffee, your body absorbs the caffeine, sending some to the brain. In the brain, the caffeine attaches to the Adenosine, blocking the receptors. But that doesn’t stop your body from producing Adenosine. Instead, it stops your body from feeling the effects of it.

So, when your body has fully metabolized your coffee, you're left feeling the effects of the Adenosine you had in your body earlier plus how much has been produced since then. In other words, you're really tired.

But it doesn't stop there. Adenosine actually binds to another receptor in the brain called A2A. The A2A receptor monitors levels of dopamine, serotonin, and adrenaline – aka the happy hormones. When Adenosine is blocked, it can’t bind to A2A, meaning the A2A can’t monitor your feel good hormones, letting them run rampant throughout the body. When the

Adenosine can bind to the A2A receptor again, the A2A controls all the hormones, and you'll feel a caffeine crash.

Reason 3. You may have a caffeine tolerance.

If you’re a coffee fanatic, you’ve probably had someone tell you something similar before. While this has some factual basis to it, there are conflicting studies out there.

One study followed eleven participants who went through two testing periods. The first was with a caffeine pill and the second with a placebo pill. After administering the pills, the researchers studied the participants' peak aerobic power. While, originally, the participants had increased peak performance, the effects of the caffeine lessened after some time and so did their performance.

Another study admitted that caffeine metabolism is affected by numerous different lifestyles. But it found that your caffeine metabolism doesn't change over time.

Either way, you know your body best, and you know how caffeine affects you. If you're feeling extra sleepy after your daily cup of coffee, you could be developing a caffeine tolerance.

Reason 4. Your coffee has too much sugar.

Have you ever considered how much sugar you put into your coffee? Sometimes, the sugar is the culprit, not the coffee. Luckily, this one has a pretty easy fix. If you think you're experiencing a sugar crash, try switching out your sugar for something else and see how you feel after that. You may be surprised by the results!

Reason 5. Coffee is a natural diuretic.

Fun fact: Caffeine is a natural diuretic. In other words, it helps move water out of your body. Now, research isn’t entirely conclusive on the extent to which coffee causes potential dehydration. But if you're not balancing your coffee intake with water, you could easily become dehydrated. And dehydration leads to fatigue. So don't forget to drink water throughout the day, too!

Reason 6. Your coffee may have mold.

Definitely not something you want to hear, I know. But some coffee beans contain what are called mycotoxins, a type of mold. Mycotoxins are linked to chronic fatigue, so it’s important to make sure you’re investing in high quality coffee beans that you can guarantee are mold-free and good for you. One way to do this is by roasting your own coffee beans and storing them properly afterwards.

Reason 7. You're going through withdrawal.

We’ve all heard of this before. The dreaded withdrawal. Withdrawal can occur for a couple reasons, but the main one is linked to your stress hormones. Your body gets used to a certain level of stress hormones every day. Without your daily cup of coffee, your stress hormones will be lower, and you'll feel more tired. You may think there's no way withdrawal would happen to you. You don't drink enough coffee for that! One research study had participants consume an average of 300 milligrams of coffee a day. Then, they cut back to 200 milligrams and 100 milligrams. Most of the participants experienced withdrawal just by decreasing their caffeine intake by that much. Now, 100 milligrams of caffeine may seem like a lot, but it's actually only one 8oz. cup of coffee. So maybe this is worth considering next time you feel sleepy after your cup of coffee.

Reason 8. You’re sleep deprived… And caffeine isn’t helping

Have you ever heard of sleep debt? Science has proven that we need a specific amount of sleep each night to function properly throughout the day. This time, obviously, ranges from person to person, but the average is around 8 hours. If you’re getting less than this amount, you accumulate sleep debt and progressively feel more tired. At this point, no amount of caffeine can truly cover for you.

But you can also cause sleep debt with too much caffeine. It takes most people 3-7 hours for their bodies to metabolize caffeine. For some, it can even take up to 12 hours. Either way, the caffeine from coffee can affect you for awhile after you drink it. If you find that you're super sensitive to the caffeine in coffee, try not to drink it in the afternoon or switch to decaf.

There's many more high quality, flavorful decaf options out there these days, so you can still enjoy your coffee and your sleep.

So, How Can You Minimize the Side Effects of Coffee?

We've already listed a couple of options, but there's many different ways you can handle this.

First, invest in quality coffee beans from a place you trust. If you’re not sure where to start, check out our green coffee beans and control the roasting, grinding, and brewing process yourself.

Second, control your caffeine intake. The FDA recommends a limit of 400 milligrams per day, which comes out to about two 16oz. cups of coffee.

Third, try to avoid super sugary drinks, or at least limit them to special occasions.

Fourth, remember to drink water with your coffee to stay as hydrated as possible.

And finally, switch to decaf in the afternoon so you don’t affect your sleep cycle.

Coffee may make you feel tired, but there are still ways to enjoy your morning cup of coffee and not succumb to that mid-afternoon slump.