Why Does Coffee Make Me Sleepy? – Knowing the Facts

More than often, right after I enjoy a cup of coffee, I feel drowsy and I end up wondering why does coffee make me sleepy? If this happens with you too, nothing to worry about – there are reasons behind that.

Along with all the positive impacts, the element of tiredness or sleepiness is usually associated with coffee. Is it just the caffeine or are there other things that play their part? – Let’s find out.

The Caffeine Effect

A regular cup of coffee will have significant amount of caffeine in it, unless you’re having a decaffeinated coffee (with traces of caffeine). Caffeine affects various parts of your body including your brain, heart, nerves and muscles.

Release of Dopamine

According to a study, daily caffeine consumption releases dopamine in the brain that leads to a faster heartbeat. It increases metabolism and eventually your body will be producing energy at a faster rate.

Due to this, your body tends to get tired and you feel drowsy or sleepy right after you have a cup of coffee.

Adenosine and Other Chemicals

Caffeine also reacts with other chemicals such as phosphodiesterase (PDE), cyclic adenosine monophosphate (cAMP), norepinephrine and epinephrine. Adenosine is a neurotransmitter that is responsible for causing fatigue.

Even though caffeine in coffee blocks your brain from receiving adenosine, your body is still producing it. So when the effect of caffeine starts to wear off, the adenosine in your body will make you sleepy.

How Long Does It Take for Caffeine to Kick In

Caffeine usually takes around 45 minutes to start kicking in, but this might vary from one individual to another. The effects of caffeine can last for up to 4 hours, depending on your body’s tolerance.

However, if you are a regular coffee person, you might not feel the same effects of caffeine as compared to someone who occasionally consumes a cup of Joe.

Sugar Crash After a Sweet Coffee Cup

Flavored coffee beverages are usually high on sugar. If you are having too much sweet in your cup of Joe, you might get a sugar crash shortly after.

This is because sugar is processed faster than coffee itself, and once your body uses up the energy, you might feel tired or sleepy.

Low Quality Coffee

If you do not want to feel sleepy right after you have coffee, try not to have the cheap stuff available in the market these days. Cheap coffee, particularly from places like Brazil and Vietnam, might make you feel drowsy.

The way this sort of coffee is produced is quite opposite to the natural process. Cherries are let to grow mold that leads to high mycotoxin levels in your cup of Joe. This eventually makes your brain to feel sleepy.

Coffee Makes You Dehydrated

Coffee is a diuretic, which means it will make you pee more than usual. Excessive loss of water from your body can lead to dehydration – with an increased heart rate and low blood pressure.

However, there are studies that oppose this concept and argue that caffeine doesn’t necessarily affect urination as compared to other drinks or beverages. Every body reacts differently to caffeine.

Moreover, caffeine in coffee is also known to cause vasoconstriction – a medical terminology in which blood vessels are narrowed that could adversely affect the blood flow in the body.

Coffee Makes You Feel Hungry

If you are wondering how can coffee make you tired or sleepy, it could be due to the increased rate of metabolism in your body that initially makes you feel hungry and then makes you feel drowsy.

Since your heart and brain, or even other parts of your body, work at a faster rate after caffeine consumption, the glucose and energy levels in your body tend to get used up rather quickly. This might lead to a sudden feel of hunger, followed by tiredness or sleepiness.

Is Coffee the Sole Culprit?

Yes, coffee does have caffeine and caffeine might make you feel sleepy at times, however, going with the assumption that coffee is the only reason behind your sleepiness might be wrong.

There could be a number of other factors that might be the reason of you feeling tired or sleepy, and not just the coffee itself. For example, if you didn’t sleep well then there are high chances that you will be yawning even after you have your favorite espresso or latte in the morning.

Or, if you have had a long day at work and you are already mentally or physically tired, you might drink a cup of coffee with the hope that it will give you the boost that you might need to keep you awake for a while. And it might work, but not for long.

Eventually, your already tired body will give up and you will tend to feel sleepy even after having a strong cup of coffee.

How To Minimize These Effects

Here are some of the ways through which you can cut down on the sleep or fatigue-related effects of coffee:

Keep a Check on Your Daily Consumption

The best way is to consume your coffee beverage in moderation. Recommended daily caffeine consumption is up to 400 mg, which means around two to four 8 oz. coffee cups per day.

Switching to decaffeinated coffee will be a better decision.

Avoid High Sugar

Another way to get rid of the drowsiness is to avoid coffee beverages with too much sugar. All those sugar-based coffee syrups and added sweeteners that you see in the cafes or restaurants, it is better to avoid those.

Time of the Day

Kicking off your day with a few cups is all good, or may be one during the afternoon when you are almost done with half of your day’s activities and tasks.

However, drinking coffee during the evening or anytime after that might react in a different way. This is because your body has already been through the ‘demanding’ part of the day and you probably need rest.

Drink Lots of Water

If you are a regular coffee drinker, make sure that you are consuming sufficient amount of water to keep you well hydrated at all times. According to the Health and Medicine Division of National Academies, the daily water consumption for adults should cross:

  • 15 cups (3.7 liters) for males
  • 11 cups (2.7 liters) for females


Can Caffeine Make You Sleepy?

Caffeine increases alertness by interfering with certain chemical processes in the brain that regulate the sleep-wake cycle. However, once the body completely metabolizes caffeine, it can make you feel sleepy.

Why does Caffeine Cause Fatigue?

Once the caffeine wears off, there’s a build-up of adenosine that will bind to your brain’s receptors, making you feel tired or fatigued.

Can coffee make you gain weight?

Coffee alone does not cause weight gain and may, promote weight loss by boosting metabolism and aiding appetite control. However, it can negatively affect sleep, which may promote weight gain.

Our Final Word on Coffee and Its Sleep-related Impacts

So the next time you find yourself wondering why does coffee make me sleepy? – you would know the various elements that are associated with coffee consumption.

You do not necessarily have to quit drinking coffee if you are getting way too sleepy or tired after drinking your favorite cup of Joe. Just some slight amendments to your drinking habits, or other factors that we have discussed above, should work.

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