Caffeine – Benefits, Dosage, Sources, and More

Caffeine and Caffeine Pills


Caffeine is a drug that makes your brain and nervous system work more quickly. To put it the other way, it is a strong stimulant.

Numerous beverages, including coffee, tea, soft drinks, and energy drinks, contain caffeine, additionally chocolate also contain this stimulant in small amounts. Compared to soft drinks, energy drinks typically contain more sugar and caffeine.

Benefits of Caffeine

It has many effects on your body’s metabolism. It:

  • Stimulates your central nervous system, which can make you feel more awake and give you a boost of energy
  • Is a diuretic, meaning that it helps your body get rid of extra salt and water by urinating more
  • Increases the release of acid in your stomach, sometimes leading to an upset stomach or heartburn
  • May interfere with the absorption of calcium in the body
  • Increases your blood pressure

It has also proven to be useful for other health conditions like;

  • Liver disease
  • Gallstones
  • Neurological disease
  • Asthma
  • Diabetes


Source of Caffeine

Caffeine is a bitter substance that occurs naturally in more than 60 plants including:

  • Coffee beans
  • Kola nuts, which are used to flavor soft drink colas
  • Cacao pods, which are used to make chocolate products
  • Tea leaves
  • Energy drinks
  • Supplements (Caffeine Pills)


How convenient are Caffeine Pills?

Caffeine pills provide a concentrated and convenient source of energy, offering its precise dosage for a quick boost. However, it is important to use them responsibly and be aware of potential side effects and interactions with medications.

Absorption and Metabolism of Caffeine

After consumption, it is absorbed within approximately 45 minutes and peaks in the blood within 15 minutes to 2 hours. Coffee, tea, and soda contain caffeine, which is quickly absorbed in the intestine and dissolves in the body’s water and fat molecules. It has the ability to enter the brain. In the gut, food or food components like fibers can slow down the rate at which its blood level peaks. Consequently, drinking your morning espresso while starving could give you a speedier jolt of energy than if you drank it while having breakfast.

The liver is where caffeine is mostly broken down. Depending on a number of factors, it can remain in the blood for anywhere from 1.5 to 9.5 hours. Its breakdown is accelerated by smoking, whereas it can be slowed by pregnancy and oral contraceptives. Also, it can remain in the body for up to 15 hours during the third trimester.



Coffee, tea, chocolate, numerous sports and energy drinks, and many other foods and beverages contain caffeine. Its levels range from 95 to 200 milligrams per cup. A cup of black tea has 25-110 mg of caffeine. Per cup, green tea has 30-50 mg of caffeine. Products containing caffeine that are sold in very concentrated or pure forms pose a health risk. It is easy for people to take much too much medication by accident. Avoid using these items.


Adults can take 180-400 mg of caffeine per day. Consult a medical professional to determine the best product and dosage for a given condition.

For children, the dose varies with age.

4 to 6 years old: 45 mg

7 to 9 years old: 62 mg

10 to 12 years old: 85 mg

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Caffeine as a Pre-Workout

The International Society of Sports Nutrition (ISSN) has concluded that caffeine is an effective ergogenic aid when consumed in doses of 0.9–2.7 mg per pound (2–6 mg per kg) of body weight.

Drinking coffee around 45–60 minutes before a workout allows this stimulant to reach its peak effectiveness in the blood. Most studies indicate that caffeine is highly effective for workouts when consumed in doses of 0.9–2.7 mg per pound (2–6 mg per kg) of body weight.


Caffeine and Adenosine Receptors

To a nerve cell, caffeine looks like adenosine. It binds to the adenosine receptor. However, it doesn’t slow down the cell’s activity like adenosine would. As a result, the cell can no longer identify adenosine because caffeine is taking up all the receptors that adenosine would normally bind to. Instead of slowing down because of the adenosine effect, the nerve cells speed up. It also causes the brain’s blood vessels to constrict, because it blocks adenosine’s ability to open them up. This effect is why some headache medicines like Anacin contain caffeine constricting blood vessels in the brain can help stop a vascular headache.

Neuron firing is accelerated as a result of caffeine’s effects on the brain. When the pituitary gland detects this activity, it sends signals to the adrenal glands to produce adrenaline (epinephrine), believing an emergency is imminent. Adrenaline is the “fight or flight” hormone, and it affects your body in a number of ways:

  • Your pupils dilate.
  • The airway opens up (this is why people suffering from severe asthma attacks are sometimes injected with epinephrine).
  • Your heart beats faster.
  • Blood flow to the stomach slows.
  • The liver releases sugar into the bloodstream for extra energy.
  • Muscles tighten up, ready for action.
  • Blood vessels on the surface constrict to slow blood flow from cuts and increase blood flow to muscles.
  • Blood pressure rises.

This explains why, after drinking a large cup of coffee, your hands become cold, your muscles become tense, you feel excited, and your heart beats more quickly.

Overdose of Caffeine

When used for an extended period or consumed in high quantities greater than 400 mg -10 grams per day (up to 80 cups in a short period of time), caffeine may pose a risk.

  • Insomnia,
  • Nervousness,
  • Restlessness,
  • Nausea,
  • Increase in heart rate
  • Headaches,
  • Anxiety,
  • Chest pain may occur at higher doses

When taken in large quantities, it probably poses a risk. It may even result in death due to irregular heartbeat.


Caffeine and muscle recovery

The American Physiological Society says that carbs and post-workout caffeine can help muscles recover. This is due to the fact that it helps transport glucose from the blood into the muscles, replenishing your stores in as little as four hours.


Caffeine and muscle fatigue

In terms of peripheral fatigue, it is well established that supraphysiological caffeine concentrations can reduce fatigue in isolated skeletal muscles. More recent in vitro studies also suggest that physiological caffeine concentrations that can be obtained through oral intake may also directly stimulate skeletal muscle and reduce fatigue.


Can caffeine cause dizziness?

Its overdose can cause nausea, diarrhea, light-headedness, and urinary frequency. Experiencing its withdrawal even after moderate chronic intake may be associated with headache, nausea, nervousness, reduced alertness, and depressed mood.

Thus, caffeine will make you dizzy somehow in both cases of withdrawal and overdose.


Will caffeine help a headache?

An increase in blood flow around the brain occurs when blood vessels swell, tighten, or undergo other changes during a headache. This increased blood stream pressure encompassing nerves, which send torment messages to the mind, bringing a headache.

Because caffeine has vasoconstrictive effects, blood vessels narrow to restrict blood flow, effectively reducing the pain. Additionally, when its is taken in mixed with prescribed medication, for example, anti-inflammatory medicine, ibuprofen, or acetaminophen, it builds the retention and strength of the drug to give quicker alleviation.



It is possible to develop a tolerance to caffeine, like many other drugs. Because of this, you will become accustomed to its effects on your body and will need to take more to get the same results. You might become physically and mentally dependent on it over time to function properly.

You can easily break this addiction by gradually decreasing your intake. Your nervous system will have time to adjust to life without the drug as a result of this.


About the Author

Saleh Siddiqui

Doctor of Pharmacy (Pharm. D) and Content Author at KeepUpFitness.

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