September 29, 2023 2 min read

How Caffeine Works on the Body

How Caffeine Works on the Body

Caffeine is a stimulant that is found in coffee, tea, energy drinks, and other beverages. It is the world's most popular drug, and millions of people use it every day to stay awake and alert.

When caffeine enters the body, it is broken down into three different molecules: theobromine, paraxanthine, and theophylline. Each of these molecules has its own unique effect on the body.

Theobromine increases oxygen and nutrient flow to the brain. Paraxanthine enhances athletic performance by increasing the rate of fat breakdown. Theophylline increases heart rate and concentration.

Caffeine also blocks the effects of adenosine, a neurotransmitter that makes us feel tired. This is why caffeine can give us a boost of energy.

However, too much caffeine can have negative side effects, such as jitteriness, anxiety, and insomnia. The recommended safe daily intake of caffeine for adults is 400 milligrams. This is equivalent to about three cups of coffee or eight cups of black tea.

Caffeine has a half-life of six hours, which means that half of the caffeine in your body is eliminated after six hours. So, if you drink a cup of coffee at 8am, half of the caffeine will be out of your system by 2pm.

How Much Caffeine is in Different Types of Coffee Drinks



47-64 MG per 1 oz


50 MG per 2 oz


100 MG per 8 oz


107.5 MG per 8 oz


95-165 MG per 8 oz


3-16 MG per 1 oz


6 MG per 8 oz 

If you are concerned about your caffeine intake, it is best to talk to your doctor. They can help you determine how much caffeine is safe for you to consume.

Tips for enjoying caffeine safely:

  • Limit your caffeine intake to 400 milligrams per day.
  • Avoid caffeine late in the day, as it can interfere with sleep.
  • Drink plenty of water to stay hydrated.
  • Be aware of the caffeine content of different foods and beverages.
  • If you experience any negative side effects from caffeine, such as jitteriness or anxiety, reduce your intake.

How Much Caffeine is in Coffee?

Decaf Coffee Caffeine & Recipes

Caffeine can be a safe and enjoyable way to stay awake and alert, but it is important to consume it in moderation.