The structure of caffeine

The structural formula of caffeine


OK so its time to start molecule of the week, and to kick us off I thought it would be great to introduce you to this fantastic molecule that keeps us going! 

Pure Caffeine, or 1,3,7-trimethylxanthine, is in fact a white crystalline substance which is responsible for some of the bitter taste of coffee. It acts as a psychoactive stimulant and is really a drug. This molecule is found in some plant leaves which the plant uses as a natural pesticide. Caffeine paralyses and even kills some bugs which saves the plant. 

Pure Caffeine Powder

Pure crystalline Caffeine


Caffeine is the worlds most widely consumed psychoactive drug, however, unlike most other psychoactive drugs it is legal and unregulated in most countries. The American version of the UK’s Food Standards Agency, The U.S. Food and Drug Administration or FDA lists caffeine as a “multiple purpose Generally recognized as safe food substance.” It is commonly found in various drinks such as Tea, Coffee and energy drinks. Some people also take caffeine tablets or pills to increase their work output or heighten their ability to concentrate. It is important to point out that whilst it is sold in almost every country in the world without the need for a prescription there is some evidence to show that it’s use or misuse can have long terms side effects and so medical advice should be sought before taking caffeine supplements. 

Pro Plus

Pro Plus Caffeine tablets


Caffeine has several well documented effects on the body, indeed a regular experiment for school children is to investigate the effect on heart rate of a coke drink, cup of coffee or similar caffeine related item. And indeed caffeine has been shown to raise the heart rate. Caffeine works as a central nervous system and metabolic stimulant. This means it is often used to reduce physical fatigue and restore mental alertness when unusual weakness or drowsiness occurs. Caffeine related products are sometimes used to correct an irregular heart beat in a newborn baby. However as with almost all drugs there are some side effects. Withdrawal symptoms include headaches, irritability, an inability to concentrate, drowsiness, insomnia and pain in the stomach, upper body, and joints and this list is not exhaustive! These withdrawal symptoms can appear from 12 to 24 hours after the last caffeine drink and can peak after roughly 48 hours. In large amounts, and especially over extended periods of time, caffeine can lead to a condition known as caffeinism. Caffeinism usually combines caffeine dependency with a wide range of unpleasant physical and mental conditions including nervousness, irritability, anxiety, muscle twitching, insomnia, headaches, and heart palpitations. Furthermore, because caffeine increases the production of stomach acid, high usage over time can lead to peptic ulcers, and gastroesophageal reflux disease. Caffeine has diuretic properties when administered in sufficient doses to subjects who have not built up a tolerance for it. Regular users, however, can develop a strong tolerance to this effect. 

Caffeine is very closely related to theobromine which is the active ingredient in chocolate 

For more information on caffeine see: 



National Geographic