The caffeine in coffee is supposed to leave you feeling refreshed, invigorated, and ready to face the day. It also provides a quick boost to your energy levels. But sometimes you experience a crash instead of a caffeine rush.
If coffee is making you feel sleepy, it might be due to stress, a high tolerance to caffeine, dehydration, or added sugars. To prevent this unwanted sleepiness, make sure you get enough sleep at night, drink plenty of water, and try natural sweeteners and plant-based milks with your cup of joe.
It can be quite frustrating when you’re looking for a pick-me-up but you find yourself yawning instead. Let’s look at some reasons why your coffee is making you sleepy and how you can prevent that side effect.
Why Does Coffee Make Me Tired?

Coffee is typically considered a wake-up drink. But sometimes, instead of providing you with that energy jolt, it can make you feel sleepy. Here are some reasons why coffee might be making you feel sleepy:
Stress
Stress can be quite disruptive to the human body. It can keep you awake at night and make you feel tired and fatigued during the day. When you’re stressed, your body produces the stress hormone cortisol, which sends signals to your mind to stay alert.
Another element of your body’s response to stress is the epinephrine commonly known as adrenaline. When epinephrine rushes throughout your body, your heart speeds up, and you breathe faster.
According to research, drinking coffee can double the level of cortisol and epinephrine in your body, even if you’re a regular coffee drinker. Your body will feel stressed even if you drink the same amount of coffee every day. This state of high alert can make you feel tired and sleepy.
Added Sweeteners
Drinking coffee with added sweeteners, such as sugar, honey, or syrup, could be the reason why you feel tired. You might be experiencing a sugar crash — not a caffeine crash. The increased sugar in your body produces additional insulin, which decreases your blood sugar levels, resulting in a sugar crash.
If you’re finding it difficult to stay awake after drinking coffee, try to drink your morning cup of joe without any added sweetener. This will help you determine if your usual sweeteners are the reason behind your sleepiness.
Caffeine Tolerance
Regular coffee drinkers build caffeine tolerance over time. Since caffeine blocks the effects of adenosine, the body reacts by starting to produce additional adenosine receptors. These additional receptors mean that you might not feel rejuvenated after your usual cups of coffee.
Contaminants
It’s quite common for mold to grow on coffee beans. Mold produces mycotoxins, which can cause chronic fatigue. The reason why you’re feeling tired after drinking coffee could be mold contamination. Other symptoms include difficulty concentrating or thinking and dizziness.
Although it’s not possible to get your coffee lab-tested before drinking it, the best thing that you can do is make sure that it’s fresh. You might be blaming your fatigue on the caffeine, but the real culprit could be microfungi.
Dehydration
It’s a well-known fact that coffee produces diuretic effects. In layman’s terms, this means that drinking coffee will make you use the bathroom more. You’ll be taking in fewer fluids and losing more, which can make you feel dehydrated, resulting in dry mouth, dizziness, and fatigue.
If you feel sleepy after consuming coffee, try drinking more water. Make sure you eat lots of foods that contain water, like fruits and vegetables, to keep your body properly hydrated. Cutting down on your daily caffeine intake is also a viable option.
How Caffeine Affects Your Stress Levels
When you’re anxious or stressed, your body goes into defense mode and releases the stress hormone that we mentioned above, cortisol. This is the reason why you experience an increase in blood pressure and heart rate during stress. But once your stress is relieved, you feel more tired than usual.
The same happens when you drink any caffeinated brew, whether regular coffee or espresso. It causes the body to produce more adrenaline and cortisol. According to research, caffeine intake can increase your body’s natural level of hormones to almost double.
So your next cup of coffee can actually make you feel stressed, and it’s natural to feel tired once the effects of caffeine wear off. People who suffer from anxiety issues and pre-existing stress are likely to be affected more by caffeine.
How Dairy and Sugar Affects the Body
Sometimes the reason why you feel tired is not the coffee, but the sugar in it. Drinking too much sugar in your coffee or consuming sugar-loaded coffee drinks induces the body to produce higher amounts of insulin. As a result, your blood sugar levels drop, making you feel anxious, irritable, and tired.
This means that you’re feeling sleepy, not because of the caffeine in your caffeinated drink, but because your body is starting to crash after an initial sugar rush. Having a sweet treat with your coffee, like a donut or a scone, can further aggravate the problem.
The best way to deal with this issue is to switch to natural, non-nutritive sweeteners such as monk fruit extract (on Amazon).
Similarly, dairy contains an amino acid called tryptophan, which helps promote sleep. It’s helpful to have dairy at night, but having it in your morning cup of coffee can be counterproductive. Although tryptophan can cause drowsiness, it’s vital to note that milk contains only a small amount of it.
You can try substituting the dairy in your coffee with a plant-based alternative like oat milk (on Amazon). If you feel more alert, then it’s a sign that you need to cut down on your dairy consumption.
Understanding Your Caffeine Tolerance
The human body is quite resilient. It can develop tolerance to any drug, including coffee. The more coffee you drink, the less it will affect your blood pressure, heart rate, and energy levels. As a result, you won’t feel the same energy as you did before you became a habitual coffee drinker.
Interestingly, when you drink large amounts of caffeine daily and the adenosine receptors are blocked regularly, the brain counters it by creating additional adenosine receptors. This means after some time, it’ll become difficult to experience the same effect from coffee, carbonated drinks, tea, or energy drinks.
The best way to combat coffee tolerance is by completely removing it from your daily routine for a few days. You can reduce your caffeine consumption by replacing black coffee with decaf. You will feel a noticeable difference in your caffeine tolerance when you switch back to black coffee.
There’s only one problem with this. If you’re a coffee lover and stop drinking coffee abruptly, you’re sure to experience caffeine withdrawal symptoms, including headaches, irritability, and fatigue. The best approach is to cut back gradually and not go cold turkey.
What Is Adenosine, and How Does Coffee Affect It?
The human body produces adenosine molecules during the day that work like neurotransmitters, carrying signals throughout the brain. Adenosine also controls our sleep-wake cycle and helps promote muscle relaxation and sleepiness.
When you drink coffee, the caffeine in it is redistributed through your bloodstream to various parts of your body, including the brain. When the caffeine reaches your brain, it attaches itself to your adenosine receptors and blocks them.
Although your brain stops processing this chemical, it doesn’t stop producing it. Once the effect of caffeine wears off, the build-up of adenosine in your brain makes you feel groggy and tired.
How to Prevent Coffee From Making You Feel Sluggish

If your coffee is making you feel sleepy, there’re a few things that you can do to rectify the situation:
Get a Good Night’s Sleep
The first thing that you should do is practice some habits that are good for your overall health. Make sure that you get at least 7-8 hours of sleep every night. This helps to reduce stress and think clearly, making it easier to focus.
Drink Plenty of Water
It’s essential to keep your body properly hydrated. The recommended amount of fluid per day for men is 13 cups, while for women it’s 9 cups per day.
Limit Your Caffeine Intake
Moderation is the key. Even if you need a caffeine boost or simply want to enjoy a cup of coffee during the day, be sure not to overdo it. It’s best to limit your coffee consumption to 4 eight-ounce cups per day.