Sebastian Freidank - 12. February 23

Caffeine Effects, Overdose, Withdrawal, Pregnancy & More


Caffeine is one of the most well-known components of plants and beverages. Most people are also familiar with the effects of caffeine, but what exactly triggers these effects and how they affect our body, general health and pregnancy are very few. In this article we will therefore give you a detailed overview of the alkaloid and highlight the side effects of caffeine, possible withdrawal symptoms and what can happen in the event of an overdose.


  1. What is caffeine?
  2. Discovery and Occurrence
  3. caffeine effect
    1. Caffeine per day - daily dose
    2. Half-life, duration of action, duration of action
    3. blood pressure
    4. Headache
    5. ADHD
    6. Health
    7. Exercise – caffeine before exercise
    8. Work
  4. caffeine pregnancy
  5. Caffeine and breastfeeding?
  6. caffeine side effects
    1. caffeine overdose
      1. Symptoms of too much caffeine
      2. Too much caffeine what to do?
  7. caffeine addiction
  8. caffeine withdrawal
    1. withdrawal symptoms
  9. Which tea has how much caffeine?
  10. Conclusion

1. What is caffeine?

Caffeine is an alkaloid found in over 60 different plants. It primarily stimulates the cardiovascular system and the central nervous system. The effect is noticeable through increased cognitive abilities, attention and focus.

Pure caffeine powder is white in color and crystalline in shape. It tastes extremely bitter and is therefore only used as an additive in industry. You find it e.g. B. in most energy drinks. You can even find it in organic energy drinks , so always check the ingredients list when looking for extracted caffeine e.g. B. want to do without because of the effect.

2. Discovery and Occurrence

Caffeine was discovered in 1820. Of course, the effect was already known through coffee and tea, but scientists, Friedlieb Ferdinand Runge to be precise, only managed to isolate the active ingredient responsible for the awakening effect almost 150 years after coffee was first imported to Germany.

Incidentally, the “theine” in tea (green tea (Matcha), black tea, white tea, etc.) is also caffeine. However, it was discovered 7 years later and named after the tea after the tea.

3. Caffeine Effect

The "wake-up effect" that caffeine triggers is actually a "don't get tired" effect. It has a similar structure to the neurotransmitter adenosine, which makes us tired and is responsible for the production of the sleep hormone melatonin.

Due to this structural similarity, the caffeine molecule can dock to the receptors that would actually be claimed by adenosine, and thus prevent the onset of tiredness.

We go into more detail in our articles on benefits and side effects .

3.1. Caffeine per day - daily dose

Strictly speaking, caffeine is a neurotoxin, which sounds very dangerous at first, but in the end it is not. See the side effects section for more information.

In order to feel the optimal effect of , it is advisable to experiment a bit yourself, because every person reacts a little differently and accordingly the best amount per day varies from person to person.

In general, you can remember the following rule of thumb from the Federal Office for Risk Assessment for a daily dose of caffeine as a good starting point:

  • A daily dose of 400 mg is classified as absolutely harmless. This corresponds to about 7 cups of Guayusa tea.
  • When ingesting a large dose of caffeine within a short period of time, the BfR sees 200 mg as the limit value in order not to suddenly strain the body with a kind of overdose. This equates to 3 to 4 large cups of Guayusa tea.
  • There are slightly different guidelines for caffeine consumption during pregnancy. More on this below or in detail here .

3.2. Half-life, duration of action, duration of action

The half-life of caffeine and its effects is an often hotly debated topic among many people. The decisive factor here is clearly the distinction between the half-life seen chemically and the time or duration of action that we actually feel.

According to the EFSA , the half-life of caffeine in the body, i.e. the time until the amount in the body has halved through degradation, is between 2 and 8 hours. Still other sources assume 1.5 hours to 9 hours.

That doesn't mean that you'll actually feel the effects of caffeine after an hour, two, or three. You can already feel tired even though you still have 90% of the active ingredient in your body, but you can also feel completely energized even though 90% has already been broken down.

The time and duration of effect of caffeine depends heavily on your personal tolerance. Correspondingly long or short it takes until it loses its effect.

The caffeine effect curve is therefore as follows with a four-hour half-life. We go into this in great detail in our comparison of artificial and natural caffeine .

Caffeine effect curve 4 hour half-life

3.3. blood pressure

How does caffeine consumption affect blood pressure? The answer to that is not that easy to give, because it depends on the form in which you take it.

Natural caffeine from plants works differently than artificial or extracted. Even the consumption of different plants has different effects, since many other active ingredients can play a role here. You can find a detailed description of these differences in our article on the effects of caffeine in guayusa .

You can find more information about the individual active ingredients that are often found in caffeinated plants in our overview " These ingredients give you unlimited energy ".

In this article we will therefore remain a little more general:

  • In its natural form by drinking coffee, guayusa, tea, mate or guarana, the alkaloid has no negative effects on people with high blood pressure. Blood pressure only spikes, and only for a short time, when caffeine has not been consumed for a long time.
  • Artificial or extracted caffeine, on the other hand, can have a negative effect on blood pressure. It can raise blood pressure and cause problems.
  • Guayusa has a blood pressure regulating effect because it also contains the active ingredient L-theanine.

3.4. Headache

Another positive effect of caffeine is the reduction of pain, especially headaches! The effect can again be traced back to a blocking function, this time of enzymes! As a result of this blocking, the hormone prostaglandin is produced to a lesser extent and can fulfill its task of communicating pain in the brain to a lesser extent.

According to a study by the University of Freiburg, home remedies such as coffee or guayusa with lemon should also help against headaches.

3.5. ADHD

Caffeine can quickly lead to hyperactivity in people with ADHD . Paradoxical phenomena, such as becoming sleepy, are also possible. However, there is no uniform scientific statement on this.

However, we keep getting feedback from our customers that guayusa, unlike coffee, helps them with their ADHD symptoms, even though guayusa is the most caffeinated drink in the world.

3.6. Health

Caffeine has some health benefits. We will not go into all of them in the smallest detail, but will name the most important ones. We'll go into more specifics in a separate section on health benefits .

  1. Reducing the risk of type 2 diabetes
  2. Up to 25% lower risk of stroke
  3. Up to 49% lower risk of cancer
  4. Lower risk of getting kidney stones
  5. Up to 20% lower risk of skin cancer
  6. Protection against cataracts
  7. Improving long-term memory
  8. Reduced risk of Alzheimer's
  9. Reduced risk of Parkinson's
  10. Increased brain function
  11. Increased performance in sports
  12. Greater alertness
  13. Improved/increased metabolism

Then we will go into more detail about the increase in performance in sports and work.

caffeine effect

3.7. Exercise – caffeine before exercise

The caffeine effects have been proven to be absolute performance enhancers. According to a study, the best level of performance should be at a dose of 3 to 6 mg per kg of body weight.

This includes all kinds of effects, such as muscle power, endurance, bounce, sprints and movements.

The caffeine dose should be taken about 60 minutes before training. However, it also depends heavily on the type of active substance consumed. Extracted, pure caffeine powder works faster than coffee, which in turn works faster than guayusa .

3.8. Work

For work, and here we are assuming mental, i.e. head work, the active ingredient offers a number of positive properties .

  1. alertness
  2. concentration
  3. Mood
  4. Limits depression
  5. motivation

4. Caffeine Pregnancy

Germans fear caffeine during and after pregnancy is widespread. The study situation is not clear, so some studies come to the conclusion that consumption of up to 200 mg per day does not pose any problems, while others assume reduced growth of the baby during pregnancy.

The BfR assumes that consumption of 200 mg spread over the day has no negative effects. The WHO sees 300 mg as a guideline.

So if you want to be on the safe side, reduce your consumption of caffeine drinks during pregnancy. As always, the dose makes the poison. A cup of coffee, tea, or guayusa never hurt anyone. We have examined the topic in detail in another article .

5. Caffeine and breastfeeding?

Drinking a few cups of guayusa, tea or coffee while breastfeeding is also not a problem. However, energy drinks should be avoided.

It is also important to know that breast milk has the highest caffeine content about 1 hour to 2 hours after consumption. So plan ahead as best you can and drink a cup of your favorite pick-me-up either immediately after breastfeeding or before breastfeeding to keep breast milk free as possible.

In order to keep breast milk completely free of caffeine while breastfeeding, you have no choice but to do without it entirely.

caffeine pregnancy and breastfeeding

6. Caffeine side effects

After all the benefits, let's look at the side effects of caffeine.

6.1 Caffeine overdose

The dose makes the poison! It is considered absolutely harmless to take a daily dose of approx. 400 mg.

However, consuming more than that 400 mg over a long period of time can result in some unpleasant side effects.

A life-threatening dose is only to be expected from 1,000 mg of caffeine. In most cases, however, extremely unpleasant side effects are more likely than a truly fatal overdose.

Symptoms of too much caffeine

Side effects or uncomfortable symptoms of a caffeine overdose may include the following.

  1. depression
  2. anxiety
  3. sleep disturbance
  4. Cardiovascular problems
  5. Enhancement of existing gout
  6. Headache
  7. tremors

In our article on side effects of caffeine, we go into more detail about the individual symptoms of an overdose.

caffeine side effects

Too much caffeine what to do?

First of all, even a caffeine overdose is unlikely to be life-threatening! As with two or three too many alcoholic drinks, the caffeine hangover simply has to be cured. The best way to do this is to:

  1. don't drink more caffeine ;)
  2. take a walk in the fresh air
  3. breathe evenly and deeply
  4. drink a lot of water
  5. possibly drinking water with extra electrolytes.

The side effects of a small caffeine overdose should wear off within 4 to 6 hours. If you have actually consumed 1,000 mg or more, consult a doctor who can give you additional liquid via an IV drip. As already written, you can find even more information in our article on caffeine side effects .

Too much caffeine what to do? caffeine overdose

6.2. caffeine addiction

Strictly speaking, caffeine is not an addictive substance in the sense of being addictive! By definition , an addictive drug must stimulate the brain's reward sector to such an extent that the reward circuitry is flooded with dopamine in extreme ways.

sugar e.g. B. causes exactly that! Caffeine, on the other hand, also stimulates the dopamine secretion, but not nearly enough. It is therefore attributed to the addictive substances in the sense of dependency. "Dependance" in English!

The big difference is that an addictive drug hardly allows the user to break free from it. A dependency drug makes it difficult for the consumer with minor withdrawal symptoms, but in the end this does not have a major impact on physical and psychological well-being.

You can find out more about this topic and why guayusa works differently despite an extremely high caffeine content in our in-depth article comparing natural caffeine and pure caffeine powder .

7. Caffeine withdrawal

For the reasons mentioned, a caffeine withdrawal is not rocket science, but of course it is not easy to do either. The body has become accustomed to it, which is why skipping your morning coffee can lead to withdrawal symptoms. Again, the note that this is much milder with Guayusa, almost not noticeable at all. Guayusa also has other health benefits .

7.1. withdrawal symptoms

Here are some symptoms you might experience from withdrawal if you've been consuming a higher dose on a daily basis. You can also find some of them under the side effects.

  1. irritability
  2. Headache
  3. slackness
  4. fears
  5. decreased concentration
  6. Little energy in general

withdrawal symptoms

9. Which tea has how much caffeine?

You can find more information in our even more comprehensive e-book on the subject of caffeinated plants and their effects . You can download it for free or add it to every order for free. Nevertheless, we would like to give you an overview of the most well-known teas.

9.1. Guayusa tea

Guayusa is nothing new for our customers, but maybe you've never heard of this plant? You can find a comprehensive article about Guayusa here and we have also linked separate articles on the effect and preparation .

Guayusa is the most caffeinated leaf in the world. With up to 7.6% and all sorts of other active ingredients such as antioxidants , guayusa is even healthier than green tea.

9.2. mate tea

One of the best-known stimulant drinks, but probably more through cold drinks than through the actual tea.

Yerba mate tea is broadly related to guayusa, but doesn't have as much caffeine as many people think. You can find an article on the content here and we have also linked an article on the effect compared to other plants.

9.3. Green Tea, Matcha, Black Tea

By definition, “tea” is just the infusion of the tea plant. Whether green, black, white or matcha tea powder, all varieties come from the same plant and are refined through different processing methods.

Each variety has a different caffeine content, so the range can go from 0.1% for really bad tea bags to 3.9% and for a few varieties even over 5%.

You can find out how to prepare green tea correctly and what the optimal brewing time is in our article on green tea brewing time .

10. Conclusion

According to drugwise, caffeine is the world's most popular drug. In our opinion, the wide distribution and use is due to the positive effect from which we humans benefit both in terms of physical fitness and mental performance.

Nevertheless, the possible disadvantages should not be left out and, of course, as with any other drug, they should always be named and taken into account. Because caffeine carries the risk of an overdose, although this is extremely unlikely.

The many advantages of the active ingredient, provided it is consumed in its natural form, overshadow the disadvantages, which usually only occur under certain conditions.

In our other articles you can read more about the health benefits and drawbacks and dive deep into the differences between artificial and pure caffeine powder . We have also written a more extensive article for all pregnant women and breastfeeding mothers .

Guayusa tea

Organic Guayusa from GUYA is original Guayusa from Ecuador. You can order our Guayusa directly from our shop and have it delivered to your home.

GUYA is Europe's first and largest Guayusa brand that offers you a large selection of Guayusa products. Our versatile Guayusa blends bring variety to your everyday life, keep you awake, focused and relaxed at the same time.

Since 2016 we have been working directly with farmers from Ecuador without intermediaries and have learned a lot about the processing of guayusa.

We look forward to your Guayusa order. 

Powder Guayusa

Buy pure guayusa tea powder. Our Guayusa powder offers you a variety of preparations without losing the organic quality.

Our PURE Guayusa Powder is original Guayusa, but particularly finely sieved to extract the powder particles . You can use the Guayusa powder in preparation of  a latte, cappuccino, espresso or for smoothies and pastries.

With the use of our Dripper , Guayusa powder can easily be used to prepare tea. The dripper's has a double-walled sieve that prevents the powder particles from getting into your tea. This way you can enjoy a delicious Guayusa tea without tea leaves in the water.


The Guayusa sets contain all our Guayusa tea flavours  as well as our tea accessories.Purchasing Guayusa in Sets is a best way to save money because  the Guayusa is in cheaper price in Sets than when sold as an individual product.

Our Guayusa comes from Ecuador and is organically grown there and traded fairly by us.

Each Guayusa set is put together differently and offers you a cheap alternative to expensive individual orders. Choose from sets with a teapot, tea glass, thermos flask, tea strainer and our 7 Guayusa varieties.


Our high-quality tea accessories made from stainless steel and special borosilicate glass have a long service life and can withstand all temperatures unconditionally! Find the right tea accessory for you in our online shop!

The glass products, as well as our stainless steel tea strainers, are suitable for any loose tea. All products can easily be cleaned in the dishwasher or under running water.

You can buy our products individually or in a combined package at a lower price.

Our tea accessories online shop also offers you a large selection of Guayusa tea which all together, as a set, make   an excellent gift.

Weitere Blogartikel

Guayusa Koffeingehalt - Mate Tee Koffeingehalt  - Großer Vergleich

Guayusa Caffeine Content - Mate Tea Caffeine Content - Big Comparison

26. March 20

Does mate tea have caffeine, how does the content compare to guayusa caffeine content & coffee? Which tea has the most caffeine? Comparison!

Natürliches Koffein VS. Reines Koffein Pulver

Natural Caffeine VS. Pure caffeine powder

13. February 23

Natural Caffeine VS. pure caffeine powder. Caffeine intolerance, duration of action and curve of action in comparison.

Koffein in der Schwangerschaft & beim Stillen – was beachten?

Caffeine during pregnancy & breastfeeding - what to consider?

13. February 23

Caffeine in pregnancy, breastfeeding and breast milk? What are the facts and what should you urgently pay attention to?

Koffein Vorteile – Positive Wirkung von Koffein auf unsere Gesundheit

Caffeine Benefits – Positive effects of caffeine on our health

13. February 23

In this article you will find out all the benefits of caffeine and how you can use these positive properties for your health and performance.

Koffein Nebenwirkung – Alle Koffein Nebenwirkungen auf die Gesundheit

Caffeine side effect – All caffeine side effects on health

12. February 23

What Are the Caffeine Health Side Effects & How Can You Avoid Them? We will give you a detailed list & description.

Der Koffeingehalt von Mate Tee - Koffein in Yerba Mate Tee

The caffeine content of yerba mate tea - caffeine in yerba mate tea

05. January 23

We compare the caffeine content of yerba mate with other caffeinated drinks and describe the different effects.

Enthält Schwarzer Tee Koffein?

Does black tea contain caffeine? - Advantages and disadvantages of black tea

14. December 22

Does black tea have more or less caffeine than other drinks? What are the advantages and disadvantages of black tea.

Das koffeinreichste Getränk der Welt – Fakten-Vergleich!

The most caffeinated drink in the world - fact comparison!

22. February 23

What is the most caffeinated drink in the world? We compare! The result surprises many because it is not guarana or coffee!

Mate Tee Wirkung - Blutdruck, Haut, Abnehmen Wirkung von Mate Tee

Mate tea effect - blood pressure, skin, slimming effect of mate

25. January 23

How does mate tea work? Everything about the effects of mate tea on the body, skin, blood pressure, weight loss and more! And Comparison Mate Tea VS Matcha Tea.

Bio Energy Drinks TOP 5 - Vergleich Bio Energy Drink 2023

Organic Energy Drinks TOP 5 - Comparison Organic Energy Drink 2023

12. January 23

The TOP 5 organic energy drinks 2023 in comparison! Find the best and healthiest organic energy drink for your lifestyle!

L-Theanin Wirkung – Konzentration, Schlaf, Depression & Koffein

L-Theanine Effects - Concentration, Sleep, Depression & Caffeine

18. February 23

Everything about the L-Theanine effect & dosage - Better sleep, less stress/depression & more memory in combination with caffeine!