Caffeine: how does it act on the body? Check out the benefits and care

Contrary to what many people think, caffeine is not a compound found exclusively in coffee (or energy drinks). In general, the consumption of these drinks is motivated by their effects that aim to provide greater energy to the body, so that the substance is a great ally in the daily lives of thousands of people.

With that in mind, we have separated more information about ideal consumption, possible risks of ingesting it, benefits and other curiosities. Check out:


What is caffeine?

Caffeine is a chemical compound in the family of alkaloids – a class of basic substances, derived mainly from plants – being present in about 60 types (as in the coffee bean).

In addition, it can also be found in industrialized products , such as some soft drinks, and is even present in the composition of some medications (such as painkillers).

It is a psychoactive substance, that is, it acts directly on the central nervous system (CNS) and has the potential to alter brain functions and provide changes in perception, mood and even behavioral.

In the case of caffeine, it is famous for its stimulating action, constantly used to increase physical potency and increase mental activity. Therefore, it is a great ally for when we need to remain more active (as) and leave aside feelings such as physical tiredness or drowsiness. Its peak of action occurs, on average, after 20 minutes of ingestion.

With regard to consumption levels, the World Health Organization (WHO) and the National Health Surveillance Agency (ANVISA) indicate the daily limit as being 400mg of caffeine for the general population.

However, when analyzing the label of some supplements, you can find higher levels (reaching 420mg of caffeine). This is because, in these cases, products intended for use by athletes are treated.

What types of caffeine: where to find?

Caffeine is available in different types, it can be in the form of supplements (capsule and powder), in some medications and even naturally present in food. Check out:

Powdered Caffeine (Anhydrous)

In general, caffeine powder (or anhydrous ) is used by practitioners of sports / physical exercises, as a means of supplementation in order to increase energy levels and provide greater physical endurance.

One of the reasons for the preference for powder consumption is because, in this way, the body generally has a faster absorption. But it is worth mentioning that the actions it performs in the organism are the same regardless of the type.

In addition, the dosage must also follow safe consumption rates (400mg). Not dispensing the follow-up with doctors (nutritionists) or nutritionists.

Caffeine in capsules

Caffeine in capsules (hard or gelatinous) is the most common form of supplementation with this substance. In general, the difference between the two forms is that gelatinous capsules are absorbed more quickly compared to hard ones.

It can be purchased at pharmacies, food supply stores or health food stores. Its consumption is often preferable due to its practicality compared to the powdered supplement.

Another advantage is that, unlike the powder version, the capsules have no taste and are more affordable – in addition to being found more easily.


As we know, caffeine can also be absorbed through foods and drinks that are part of our daily lives – such as black and mate tea , guarana, coffee, chocolate, cola drinks, energy drinks, among others.

In this case, because you are not ingesting the pure substance, the absorption time varies depending on what you eat or drink. Since the higher the caffeine content, the faster the absorption will be – that is, coffee has faster effects than chocolate, for example.


Caffeine is also present in the formulation of some medications – especially analgesics, which have the function of relieving pain.

In these circumstances, it acts as an adjunct . That is, it provides an aid to the drug (active principle) that makes up the medication. Its action is important because it blocks adenosine receptors – which are responsible for transmitting the painful signal.

In addition, some studies also show that caffeine improves the absorption of the drug by the body and can increase the analgesic effect of the drugs indicated for the control of acute and chronic pain.

What is the difference between caffeine and anhydrous caffeine?

Anhydrous caffeine is the powdered version of the substance. In general, the difference between it and caffeine is in the amount of water associated with the molecule. This is because the anhydrous type does not have a considerable amount of water in its composition (only 0.5%). Thus, the term “caffeine” can refer to any version.

In contrast, the term “anhydrous” is always associated with the powder version. It is obtained from the extraction of grains or seedlings, which are subjected to boiling at high temperatures. With this, the water is completely removed, which produces a white, crystalline powder – characterizing the anhydrous form.

Still, it is worth noting that due to its low water content, studies and chemical analyzes understand that it can be more potent and guarantee faster absorption.

What is caffeine for?

The consumption of caffeine is part of the routine of many people, motivated mainly by its energetic action . This action can be seen in different aspects:

Give more energy and avoid sleep

We know that the vast majority of people see caffeine as a source of energy and fight sleep or fatigue .

In practice, this substance really serves these purposes. This is because, when in contact with our organism, it acts on the central nervous system (CNS) as a potent stimulant .

Thus, the person starts to feel more willing and active, considering that caffeine neutralizes the feelings of physical and mental tiredness. Thus, one does not have the real perceptions of sleep, giving way to the energy provided by the substance.

Improves concentration

Due to its stimulating action, caffeine starts to inhibit the action of adenosine (a substance that acts as a type of “brain tranquilizer”).

With this, our brain starts to be constantly on alert, which generates the effects desired by many people: more attention and concentration.

Therefore, the recommendation is that it should not be ingested during the night, considering that it can cause interference in sleep.

Improves physical performance

Another recurrent use of caffeine is related to the practice of physical activities. This can also be quite effective considering the ergogenic effect of the substance.

That is, caffeine maximizes the physical performance of our body – an advantage for exercise, especially in conjunction with the other effects of the substance.

Benefits: when is caffeine good?

Considering that caffeine is a substance with stimulating actions (which can also be classified as a benefit), to enjoy all the good actions of the substance, it is very important to consume moderately .

In addition to its main functions, check out other benefits that it can provide:

  • It can contribute to a good memory;
  • It has thermogenic action – which contributes to a good functioning of the metabolism;
  • Helps to combat fluid retention – considering that it has a diuretic action;
  • It contributes to the release of neurotransmitters (such as serotonin and norepinephrine) – which can improve mood and psychomotor performance;
  • It has antioxidant action – combating cell aging.

It is also worth noting the fact that studies have shown that caffeine can be beneficial in the treatment of some neurodegenerative diseases (such as Parkinson’s and Alzheimer’s).

Harm: does excess caffeine hurt?

-Yeah . Just like anything, excess caffeine can also be harmful. Even in the most severe cases, this abusive consumption can even cause an overdose, and it is common for the person to present symptoms such as:

  • Acceleration of heart rate;
  • Delusions and / or hallucinations;
  • Vertigo (dizziness);
  • Headaches;
  • Convulsions;
  • Fever;
  • Shortness of breath or difficulty in breathing;
  • Chest pains;
  • Involuntary spasms.

In this case, it is necessary to seek medical help immediately – when, often, the person needs to perform gastric lavage or ingestion of activated charcoal. It may also be necessary to hospitalize and use medication to control symptoms.

In addition, in milder cases, it is possible to notice some side effects of excess caffeine such as stomach pain, insomnia and restlessness / anxiety .

Therefore, the ideal is to ingest this substance within the ideal daily dose – maximum of 400mg per day (approximately 3 cups of coffee, for example) for adults.

It is important to keep in mind that frequent consumption can generate tolerance. With this, the organism adapts to the substance and its actions, so that larger doses are increasingly needed to achieve the desired effect.

How to take caffeine supplement? How much to consume per day?

Before taking any type of supplementation, it is essential to seek medical specialists in the field of nutrology or a nutritionist. Thus, from exams, it will be possible to understand which is ideal for you and the best dose.

In general, caffeine supplements vary in powder or capsule versions – these being the most common. They provide the body, from a single dose or two, with the maximum daily amount of the substance (400mg).

That is, when administering this type of supplement, you cannot ingest the substance in other ways (such as drinking coffee, for example), since it would result in an overdose.

Some options for caffeine supplements are:

  • Catarinense Caffeine – two capsules daily, totaling 420mg;
  • Anhydrous Caffeine Health Labs – two capsules daily, totaling 420mg;
  • Caffeine Supplement Ripped DNA Supplements – two capsules daily, totaling 400mg;
  • Caffeine Droga Raia – two capsules daily, totaling 420mg.

It is worth noting that the differences in dose of supplements vary according to their indications and registration. Considering that WHO and ANVISA indicate the maximum daily consumption of 400mg for the general population.

When products are found with higher indexes than these, they are supplements recommended only for athletes – so some reach 420mg daily.

In addition, some supplements are not entirely pure, taking other substances together (such as guarana or citrus). Then, the need for guidance from an expert is reinforced to choose the best option for you.

Where to find caffeine: food and drinks

As mentioned in a previous topic, caffeine can be found in many foods and beverages. Thinking about it, check out some options and the amount of the substance per serving:

Food / DrinkThe amountCaffeine content
Milk chocolate40g10mg
Matte tea200mL20mg – 30mg
Glue coolants350mL35mg
Chocolate250mL4mg – 8mg
Iced tea (industrialized)350mL30mg – 60mg
Traditional coffee200mL70mg — 140mg
Energetic250mL60mg — 80mg

In addition to these, it is possible to find a considerable caffeine content in some other plants or fruits – such as guarana, for example.

It is also worth noting that, in the table, there are only a few examples, it is important to keep in mind that caffeine is also present in other types of teas, chocolates, etc.

What is the effect of caffeine on the body?

From the moment it comes into contact with the bloodstream, caffeine acts in several areas of our body. In general, its stimulating effect acts on our central nervous system and also increases the heart rate.

But it is not limited to that, check out how this substance acts in a specific way in some parts of our organism:


Caffeine acts directly on the brain (in the central nervous system – CNS) and promotes the blocking or release of neurotransmitters. In this sense, its main action is to inhibit adenosine (responsible for the sensation of sleep).

This allows brain stimulants to continue to act actively. In this way, one has the feeling of being more awake, changing the body’s capacities regarding the perception of tiredness, increasing focus and even being able to improve mood.

In addition, its vasoconstrictor properties increase blood flow in the brain, which can have an analgesic effect (which can help against problems such as headaches).

Adrenal gland

The actions of the brain directly affect the functioning of other areas of the body, including the adrenal gland – responsible for producing hormones that, among other functions, act in the body’s response to situations of stress .

Thus, due to the attention state of the brain, this gland understands that the body is on alert. This stimulates the production of adrenaline.

This hormone, in addition to providing more energy to the body, also dilates the airways, which can be beneficial for people who have respiratory diseases, such as asthma . In addition, it increases the blood flow of the muscles, which favors greater resistance in the practice of physical activities.


Caffeine is absorbed quickly by the body. After entering the body, it takes about a few minutes to be carried to the liver – it is there that it will be absorbed and metabolized, being distributed to the body and reaching the brain via the bloodstream.

In other words, it is the liver that makes it possible, among other actions, for caffeine to generate its desired effects for many people: promoting alertness (more concentration) and inhibiting the feeling of tiredness.

It is worth mentioning that, especially in the kidneys, it also contributes to a diuretic action – favoring the elimination of toxins and avoiding fluid retention.

How long does the effect of caffeine last on the body?

The peak performance of caffeine in the body lasts about 30 to 120 minutes. But, after that time, the substance remains active in the body – the total effect can last, on average, from 3 to 7 hours. Since the variation of time occurs according to the type of caffeine ingested.

As we saw in a previous topic, the caffeine content also varies according to the way we choose to ingest (supplements, food, etc.). Which is a determining factor in terms of the time and intensity of the substance’s effects – the higher its content, the more potentiated the action will be.

What to do to pass the effect of caffeine?

If you have taken more caffeine than you should, or are feeling unwell, with symptoms such as weakness or dizziness, take practical steps. The ideal is to carry out a brief ” detoxification ” process: drink plenty of water to eliminate the substance from the body and eat something – this will help to neutralize the effects.

However, it is worth noting that sugar is not a good ally at this time, as it also alters the body’s perceptions. Therefore, give preference to salty and natural foods.

Also, if you are feeling anxious or agitated, try these procedures and stay for a few minutes in a quiet place. Take a deep breath and do your best to return to your normal state.

As we have seen, in some cases, excess caffeine can have serious consequences. Therefore, if these steps are resolved, seek medical assistance immediately.

More than that, always pay attention to make a safe consumption and within the limits recommended as safe.

Caffeine lose weight? Is it thermogenic?

Among the benefits of caffeine, is yes thermogenic action. This means that foods / beverages that contain this substance can slightly increase metabolism – which is responsible for transforming calories from body fat into energy, as well as those we absorb from food.

This action can cause the body to spend a little more calories. Therefore, ingesting substances with this property can help with weight loss, especially when consumption is combined with healthy eating and physical activity.

But caffeine alone does not lose weight. Its action on the body can boost the metabolism and also prevent fluid retention, due to its diuretic action, helping to combat the feeling of body swelling.

However, for a healthy and effective weight loss, the ideal is to seek out a nutritionist in order to receive guidance consistent with your circumstances.

Does coffee have too much caffeine?

-Yeah . Coffee is the drink with the highest caffeine content per serving, but this can vary depending on the type of coffee you are using. Considering that there are different types, from decaffeinated (contains up to 4mg per serving) to the strongest (up to 140mg per serving).

In addition, when coffee beans are freshly ground to prepare coffee, caffeine levels tend to be higher than that of instant coffee. It is also worth noting that instant coffees (machine-made or not) have lower doses of the substance.

In general, a cup of coffee (200mL) contains from 70mg to 140mg – which represents a high amount, considering that daily consumption should not exceed 400mg.

How much caffeine is in the energy drink?

The amount of caffeine in the energy drink may vary depending on the brand and the different types, considering that today there are options ranging from traditional to flavored – besides that it is possible to find both in drink and in capsules.

But in general, regular energy drinks contain about 80mg of caffeine per serving (250mL). It is important to consider that this amount is within the daily limits, however, in all cases the value is added to the other daily intakes of the substance.

In practical terms, this means that everything you consume with caffeine throughout the day, is counting towards 400mg daily (maximum dose). Therefore, pay attention to your consumption so as not to exceed the ideal limit.

Caffeine is consumed daily by people around the world – mainly through coffee. Therefore, knowing more about this compound is very important, since it makes it possible to consume safely and learn more about how it works in our body.

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