Athletic young man opening can of energy drink

Imagine this scenario: after working hard preparing documents all morning, you start to feel sleepy as the afternoon drags on. It’s time for a snack break to refuel energy, but what should you eat? You’re working against an end of day deadline for your assignment, so you have to fuel up quickly. This is why you opt for the easier option, an energy drink.

Unfortunately, this scenario is all too common. While energy drink consumption can boost your energy in the short term, it can also make you feel even more tired afterwards.

If you’re one of many people who feel sleepy rather than spry after having energy drinks, read on to discover the reasons. That way, you’ll know what to consume—and what to avoid—to feel energetic wherever the day takes you.

Reason #1: The Ingredients

The potential mind-boosting, body-moving powers of an energy beverage largely stem from its ingredients. While these drinks may vary based on taste, size, and calories, many contain similar ingredients. These ingredients include:1

  • Caffeine
  • Sugar
  • Taurine
  • Guarana

Although studies suggest that these ingredients can increase alertness and energy, they cause our bodies to crash even harder.1

Let’s explore each ingredient in-depth, specifically focusing on how they can pick you up before you suffer a caffeine crash.


People worldwide have long praised caffeine consumption—and for good reason. In addition to helping you stay awake and alert, caffeine may help prevent certain diseases.2 However, caffeine can also cause a crash after the initial energy boost wears off.

If you’re asking yourself, “why does caffeine make me sleepy,” you may find the answer in caffeine's pharmacological properties. The chemical promotes sleep in the following ways:1

  • By backing up adenosine receptors – Blocking the brain’s adenosine receptors is one way caffeine makes you feel energetic. These receptors help enable sleep by catching sleep-promoting neurotransmitters. However, even though your adenosine receptors are temporarily blocked, your neurotransmitters keep firing. This results in a buildup of neurotransmitters that hits your adenosine receptors once the caffeine wears off.
  • By functioning as a diuretic – As a diuretic, caffeine causes the body to expel more water than normal.3 This can lead to dehydration. When you’re dehydrated, your blood tends to thicken, preventing the easy movement of vital nutrients and minerals. Without these nutrients and minerals, you may feel sluggish—especially as the day wears on.

  • In general, the more caffeine an energy drink contains, the steeper the dropoff in energy levels following the caffeine crash. Most energy drinks contain caffeine ranging from 70 to 200 milligrams per 16-ounce serving.1

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    From candy bars to sports beverages, dried fruits to energy drinks, sugar is found in many foods and drinks. In fact, sugar is so prominent in our diets that dieticians recommend people limit their sugar intake to no more than 150 calories a day.4

    Because of this, it is important that you consider what food gives you energy while making sure it is still healthy for you. Sugar can be both beneficial and detrimental for your body. While sugar can boost energy levels, too much of it can also lead to a host of health consequences, including:5

    • Obesity
    • Diabetes
    • Metabolic syndrome
    • Some cancers
    • Cardiovascular disease

    Sugar can also cause you to feel like you’ve just run a marathon after the initial burst of energy wears off. Here’s how sugar can make you feel tired:6

  • Increased insulin production – When you eat a meal loaded with sugar, you get more than a burst of sweetness on your taste buds. You also get increased insulin production. In short, insulin is a hormone produced by the pancreas that absorbs the body’s excess sugars. This increase in insulin can make you feel tired.

  • Nutrient composition – As a simple carbohydrate, sugar provides the short-term energy benefits of carbohydrates. However, consuming excessive carbohydrates—especially simple carbohydrates—can lead to fatigue. That’s because the body easily metabolizes carbohydrates, leading to an energy deficiency after all the carbs have been processed.

  • Like caffeine, sugar is a prominent ingredient in many energy drinks. Most energy drinks contain between 50 and 62 grams of sugar per 16-ounce serving.1


    Taurine is a vital amino acid that supports brain and heart functions. Taurine can help the body function in the following ways:1

    • May improve retinal function
    • Can improve bile acid conjugation
    • May lessen exercise-induced DNA damage

    When paired with caffeine, taurine has been shown to help improve mental acuity.7 However, other studies show that taurine can increase lethargy.8 That’s because taurine can interact with the sleep-promoting GABA receptor.8

    What’s surprising is that energy drinks include taurine, despite it negatively interacting with caffeine, and ultimately slowing us down. Most energy drinks contain 2,000 milligrams of taurine per 16-ounce serving.1


    A plant native to Amazonian rainforests, guarana contains high levels of caffeine. In fact, with caffeine levels ranging from two percent to eight percent, guarana contains the most caffeine of any plant. This makes guarana a popular additive in any energy beverage.9

    However, while guarana can boost energy levels in the short term, its high caffeine content can lead to tiredness. This is primarily due to adenosine receptor backup.9

    Furthermore, guarana can cause tiredness in the following ways:9

  • The plant can inhibit hunger – Given guarana’s high caffeine content, the plant has been shown to inhibit feelings of hunger. As a result, people are less likely to eat while consuming drinks containing guarana. This can lead to nutrient deficiency, low blood sugar, and increased fatigue.

  • The plant contains theobromine and theophylline – Like caffeine, the stimulants theobromine and theophylline can increase energy. However, by causing a neurotransmitter buildup, they can also promote sleepiness.

  • The amount of guarana in most energy drinks is unknown. That’s because many energy drinks do not list the exact amount of guarana in each drink. When they do, guarana extract levels tend to hover around 50 milligrams per 16-ounce serving.1

    Reason #2: Caffeine Tolerance and Withdrawal

    As one of the most consumed drugs worldwide,10 caffeine can make users euphoric, energetic, and alert.10 However, like many drugs, increased caffeine use can lead to tolerance and dependency. When this happens, withdrawal symptoms may occur if the body isn’t getting enough caffeine.

    In short, caffeine withdrawal involves several overlapping physical, emotional, and neurological symptoms. The most common symptoms include:10

    • Anxiety
    • Depression
    • Lack of sleep
    • Drowsiness
    • Fatigue
    • Headache

    In other words, if you have a caffeine dependency, you may feel groggy as soon as the caffeine in your body wears off.10

    Reason #3: A Lack of Sleep

    Energy drinks’ stimulating properties can partially answer the question, “why do energy drinks make me tired?”

    When we consume caffeine and other stimulating ingredients, our bodies may become energetic and alert. However, with this increased energy comes potential sleeplessness. Energy drinks’ ability to disrupt sleep can be especially significant if we consume high amounts of stimulants later in the day.

    According to one study, adolescents reported increased difficulty sleeping and increased tiredness in the morning the more caffeine they consumed.11

    In other words, if you consume energy drinks, you may have trouble sleeping at night. As a result, you may feel tired the next day.

    Natural Ways to Get Energy

    As we’ve seen, energy drinks can help boost energy levels. They can also lead to sleepiness. As a result, switching to natural energy boosters may help you achieve your energy goals without succumbing to the energy crash.

    Here are several ways to boost your energy levels naturally:

  • Consume drinks lower in caffeine – If drinks high in caffeine can lead to increased lethargy, drinks lower in caffeine may help you stave off fatigue. You might also consider switching to beverages chock full of antioxidants and natural sources of caffeine. These drinks include coffee and tea.12

  • Exercise – Several studies show a relationship between moderate daily exercise and increased energy levels.13 The good news is that you don’t have to engage in strenuous exercise to feel its energy-increasing benefits.

  • Take natural supplements – Many studies suggest that vitamins and minerals such as vitamin C, iron, and magnesium can decrease feelings of fatigue.14 Consequently, taking supplements containing these nutrients may increase natural energy. What’s more, some studies suggest that certain functional mushrooms like lion’s mane may help fight fatigue. Taking natural mushroom supplements is a great way to improve energy levels without putting unnecessary additives into your body.

  • Properly rehydrate – As stated above, caffeine’s diuretic properties can contribute to dehydration. This can, in turn, lead to tiredness. Proper rehydration is thus one way to naturally boost energy levels. While you could drink water to rehydrate, you could also take hydrating supplements to replenish vitamins, nutrients, and electrolytes.

  • Eat more nutrient-rich foods – Consuming excess sugar and other simple carbohydrates can sometimes make you reach for your pillow. Instead, reach for high energy levels by eating foods loaded with complex carbohydrates and proteins. So does protein give you energy? Protein has several health benefits and boosting energy happens to be one of them.

  • Boost Energy Naturally with Cymbiotika

    Energy drinks can help you get through the day because of their caffeine content. That said, they may also cause you to feel tired after the effects wear off. The last thing you want is to see your productivity decline with each sip of an energy drink.

    Fortunately, Cymbiotika can help boost your energy levels the natural way. Our Golden Mind may be especially effective. Packed with plant-based, natural ingredients, Golden Mind may help boost cognitive function and increase focus.

    You might also try our nutrient-rich Plant Protein. Aside from potentially increasing energy, our Plant Protein may also support gut health and enhance athletic recovery.

    Whichever Cymbiotika supplement you try, rest easy knowing that you’re getting the best in natural energy.


    1. Mayo Clinic Proceedings. Energy Beverages: Content and Safety.
    2. Critical Reviews in Food Science and Nutrition. Dietary sources, health benefits, and risks of caffeine.
    3. Frontiers in Nutrition. Coffee with High but Not Low Caffeine Content Augments Fluid and Electrolyte Excretion at Rest.
    4. Circulation. Dietary sugars intake and cardiovascular health: a scientific statement from the American Heart Association.
    5. Clinical Diabetes. Sugar.
    6. StatPearls. Physiology, Carbohydrates.
    7. Mayo Clinic. Taurine is an ingredient in many energy drinks. Is taurine safe?
    8. Nature and Science of Sleep. Effect of taurine and caffeine on sleep–wake activity in Drosophila melanogaster.
    9. Evidence-based Complementary and Alternative Medicine. Guaraná's Journey from Regional Tonic to Aphrodisiac and Global Energy Drink.
    10. StatPearls. Caffeine Withdrawal.
    11. ScienceDirect. High caffeine intake in adolescents: associations with difficulty sleeping and feeling tired in the morning.
    12. American Society for Clinical Nutrition. Acute effects of tea consumption on attention and mood.
    13. Sports Medicine. Physical activity and feelings of energy and fatigue: epidemiological evidence.
    14. Nutrients. Vitamins and Minerals for Energy, Fatigue and Cognition: A Narrative Review of the Biochemical and Clinical Evidence.

    by / Jul 28, 2022