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Nearly everyone has heard of caffeine: a chemical compound that is known to help keep you awake. With it varying in everyday drinks like coffee from your local cafe to a traditional cup of green tea brewed at home, caffeine is something that has been normalised throughout the entire world.


 You can even see this happening with yourself as well. Perhaps, it’s the most prominent during your exam season, studying at 2 am with a cup of coffee that is always there to accompany you to aid your studies Observe the people around you; without a doubt, at least one person as consumed caffeine today already. Making caffeine a staple in many individuals’ lives.


 With caffeine being a drug that 90% of adults worldwide consume, it is one of the most addictive and common drugs around the globe. When a significant percentage of our population consumes this drug without even batting an eyelash at it, caffeine is clearly, without a doubt, something that had become a necessity for the majority.

But do you know exactly how this drug works?


First of all, what is caffeine? Caffeine (C8H10N4O2) is a stimulant, meaning it increases activity in your brain and nervous system. It works by increasing the circulation of chemicals like adrenaline and cortisol, it results in the consumer feeling refreshed and awake after intake. 


How does it work? 

When consumed, caffeine is absorbed into the bloodstream through your digestive system, it then travels to your liver and is broken down into compounds and chemicals that affect various organs in your body. 


One of these compounds function by blocking the effects of adenosine - a neurotransmitter, calms down the brain causing you to feel tired or sleepy - caffeine does so by connecting the adenosine receptors in the brain without activating them, blocking the effects on the nervous system. This subsequently stimulates the brain and encourages a higher level of alertness and focus. 


Effects of caffeine

Studies show that caffeine has been an aid in improving mood and brain function. Since the compound blocks the brain signalling molecule adenosine, this causes an increase in other signalling molecules including dopamine and norepinephrine. In addition, caffeine has been shown to enhance your metabolism rate, because of how caffeine stimulates the central nervous system, the drug has been shown to increase metabolism rate by up to 11%. Other than that, caffeine has many other positive effects such as liver protection, decreased cancer risk and skin protection. Making it adequate to consume in small dosages. 

With the positives comes the negative side effects. On the other hand, if consumed irresponsibly caffeine may promote negative side effects such as headaches, migraines, trouble sleeping and high blood pressure in some individuals. Caffeine can also increase your heart rate, hence if consumed too much can change the speed and regularity of your heart. This is known as tachycardia or cardiac arrhythmia which can cause heart failure.

Overall caffeine if consumed in appropriate dosages, is considered healthy and can promote good health with the beneficial side effects. Consumed heavily however, can cause long term and short-term effects and health problems which can be serious to the human body if not treated.

Works cited: 

Alcohol and Drug Foundation. “ADF - Drug Facts - Caffeine.” ADF - Alcohol & Drug Foundation, 16 Dec. 2020,


Deneen, Niles. “Coffee Statistics 2018 U.S. | How Many People Drink...” Deneen Pottery, Deneen Pottery, 18 Feb. 2019,


Dunwiddie, Thomas V., and Susan A. Masino. “The Role and Regulation of Adenosine in the Central Nervous System.” Annual Review of Neuroscience, vol. 24, no. 1, Mar. 2001, pp. 31–55, 10.1146/annurev.neuro.24.1.31.


National Coffee Association. “NCA Releases 2020 National Coffee Data Trends, the “Atlas of American Coffee.””, 26 Mar. 2020,


Petre, Alina. “What Is Caffeine, and Is It Good or Bad for Health?” Healthline, 3 June 2020,


US), Medicine. “Pharmacology of Caffeine.”, National Academies Press (US), 2014,


Hartney, Elizabeth. “The Effects of Caffeine on the Brain.” Verywell Mind, Verywellmind, 22 May 2012,

Written by Najai (Waan-Yen) Wongpaibool 

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