How Coffee Works as a Stimulant, Explained in 1 Minute by a Pharm Graduate

1. The active ingredient of coffee is caffeine.

Caffeine is a central nervous system stimulant. It's typically used to reduce fatigue and drowsiness, although there are other medical uses.

2. The effects of drinking coffee usually start after 15 minutes.

It peaks around 1 hour after. Most people will experience a caffeine half-life (the time it takes for your body to rid of half the caffeine) of 5 hours. There are numerous factors that can affect caffeine metabolism, including smoking (reduces half-life), pregnancy (increases half-life), and liver disease.

3. Caffeine stimulates your brain.

It primarily acts by antagonising (blocks the action of) adenosine receptors. The blocking of a particular type of adenosine receptors in your brain is responsible for stimulating wakefulness. Together, they also result in the improvement of cognitive function, learning, motivation, and motor response.

4. Caffeine also acts on your body.

Your body also has adenosine receptors. Blocking them results in release of stimulatory neurotransmitters such as norepinephrine (noradrenaline) & dopamine. This increases heart rate & breathing rate. Caffeine also promotes kidney filtration (resulting in more urine) & digestion.

5. Caffeine may have wider health benefits aside from wakefulness.

Studies have linked coffee/caffeine consumption (after adjusting for confounding variables) with a lower risk of death. It may also have uses in slowing neurocognitive decline and treating certain cognitive conditions, although this is still under study.