How Does Caffeine Work?

Updated on June 27, 2018
K S Lane profile image

K S Lane is a student of pharmacology and has a deep and passionate interest in all kinds of ailments and medications.

Caffeine is the most widely consumed drug in the world. From coffee to tea, we all love to get our daily hit of the stuff on sleepy mornings. But what is caffeine, exactly? Where does it come from, how does it work, and are there side effects from drinking too much of it?

While everyone is happy to drink it, not everyone wonders how caffeine actually works.
While everyone is happy to drink it, not everyone wonders how caffeine actually works. | Source

What is Caffeine?

Caffeine is a nitrogenous molecule with a chemical formula of C8H10N4O2. In its pure form, it’s a white powder that looks a little like cocaine. Like cocaine, it’s classed as a stimulant drug because of the 'kick' it gives the body. Unlike cocaine, it’s perfectly legal and is drunk by the gallon by sleep-deprived students and workers across the globe. Caffeine’s chemical name is 1,3,7-trimethylxanthine, which is pretty cool but also pretty impossible to pronounce correctly.

Where Does Caffeine Come From?

Caffeine comes from a variety of natural sources, including tea leaves, kola nuts, cacao beans, guarana and, of course, coffee beans. It’s used in a wide range of commonly consumed drinks, including coffee, hot chocolate, tea, coca-cola, energy drinks and even in some types of chewing gum.

Product
Caffeine content (mg/100ml)
Coffee: Cappuccino
101.9
Coffee: Flat White
86.9
Dark Chocolate
59.0
Red Bull
32.0
Black Tea
22.5
Green Tea
12.1
Coca Cola
9.7
(Source: https://adf.org.au/drug-facts/caffeine/)

How Does Caffeine Work?

To understand how caffeine really works a little background knowledge is needed. The human body has several mechanisms that regulate how tired you feel. One of these mechanisms works through the secretion and detection of adenosine, a neurochemical that is released as a kind of by-product of your neurons firing. As the day wears on and your neurons fire as you think, walk, run, sit, and eat adenosine levels in the body start to increase. This increase is detected by adenosine receptors, which send signals to the brain telling you that it’s time for a nap.

Caffeine has a similar molecular structure to adenosine and can fit into adenosine receptors and block them.
Caffeine has a similar molecular structure to adenosine and can fit into adenosine receptors and block them. | Source

As shown in the picture above, adenosine and caffeine have a vaguely similar molecular structure. This similarity is critical in what makes caffeine work. Because of it, caffeine is able to bind to adenosine receptors and block them. This prevents the receptors from being able to monitor adenosine levels and relay the information to the brain. Essentially, caffeine stops adenosine receptors from telling the brain that you’re tired.

But caffeine doesn’t just stop you from feeling sleepy; it gives you that pleasant buzz as well. How does this factor into the caffeine molecule’s effect? Basically, the blockage of adenosine receptors in the brain allows the dopamine centre of the brain to run rampant and start pumping out the feel-good chemical like crazy. To add to the buzz, high adenosine levels in the blood trigger the release of adrenaline, which is why some people swear by caffeine when it comes to productivity.

One person's interpretation of the wonderful high and brutal crash delivered by caffeine
One person's interpretation of the wonderful high and brutal crash delivered by caffeine | Source

Does Caffeine Have Side Effects?

In the short term, consuming too much caffeine at a time blocks up too many of the brain’s adenosine receptors. Adenosine levels in the body get higher and higher and the chemical has nowhere to go. Eventually, once the caffeine wears off and the poor receptors are able to function normally again they’re hit with a huge rush of adenosine and start sending frantic demands to the brain for sleep. This is what causes the 'crash' that many people experience after drinking too much caffeine. This fatigue is generally accompanied by other symptoms, such as dizziness, a dry mouth, tremors, blurred vision and irritability.

Long-term reliance on large amounts of caffeine can have some pretty scary side effects. These include osteoporosis, high blood pressure, heart disease, heartburn, ulcers, infertility, and mental health issues like anxiety and depression. While it seems harmless when friends and coworkers rave about how they can’t function without coffee, caffeine dependency is serious stuff and shouldn’t be taken lightly. If you’re about to have your fourth cup of coffee of the day, maybe consider putting it down and drinking some water instead.

Some side effects of caffeine usage include dizziness, anxiety and tremors.
Some side effects of caffeine usage include dizziness, anxiety and tremors. | Source

In Summation:

Caffeine, or 1,3,7-trimethylxanthine, is a nitrogenous molecule that comes from a variety of natural sources like tea leaves, coffee beans and cacao. Because of its similarity to the neurochemical adenosine caffeine is able to block adenosine receptors, which surpasses the "time to sleep" messages that the receptors send to the brain. This causes the consumer to feel more alert. The other effects of caffeine come from the increased dopamine and adrenaline secretion caused as a side effect of the blockage of adenosine receptors. While caffeine isn’t particularly dangerous as far as drugs can go, consuming too much of it can cause a caffeine 'crash,' and in the long term can lead to more serious side effects like heart disease, infertility and addiction.

Test your caffeine knowledge here!

view quiz statistics

Questions & Answers

    © 2018 K S Lane

    Comments

      0 of 8192 characters used
      Post Comment

      • Black Butterfly2 profile image

        Black Butterfly2 

        4 months ago

        Very well written and informative article! Thank you!

      • K S Lane profile imageAUTHOR

        K S Lane 

        4 months ago from Melbourne, Australia

        Pamela- thanks for your kind comment. Two cups of coffee probably isn't going to do you any great harm, but you're definitely right that some of the caffeinated drinks out there are very unhealthy.

      • Pamela99 profile image

        Pamela Oglesby 

        4 months ago from Sunny Florida

        This is a great article for those of us that drink caffine regularly. I drink 2 cups first thing in the morning. I don't think the caffeine filled drinks that are not available are good for you at all. I appreciate the factual information you wrote about in your article.

      working

      This website uses cookies

      As a user in the EEA, your approval is needed on a few things. To provide a better website experience, owlcation.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

      For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://owlcation.com/privacy-policy#gdpr

      Show Details
      Necessary
      HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
      LoginThis is necessary to sign in to the HubPages Service.
      Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
      AkismetThis is used to detect comment spam. (Privacy Policy)
      HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
      HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
      Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
      CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
      Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
      Features
      Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
      Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
      Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
      Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
      Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
      VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
      PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
      Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
      MavenThis supports the Maven widget and search functionality. (Privacy Policy)
      Marketing
      Google AdSenseThis is an ad network. (Privacy Policy)
      Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
      Index ExchangeThis is an ad network. (Privacy Policy)
      SovrnThis is an ad network. (Privacy Policy)
      Facebook AdsThis is an ad network. (Privacy Policy)
      Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
      AppNexusThis is an ad network. (Privacy Policy)
      OpenxThis is an ad network. (Privacy Policy)
      Rubicon ProjectThis is an ad network. (Privacy Policy)
      TripleLiftThis is an ad network. (Privacy Policy)
      Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
      Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
      Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
      Statistics
      Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
      ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
      Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)