Caffeine

A natural central nervous system stimulant widely consumed in coffee, tea, and energy drinks.

What is Caffeine?

Caffeine is a naturally occurring stimulant belonging to the methylxanthine class of compounds. It is most commonly found in coffee beans, tea leaves, cocoa beans, and kola nuts.

It is the most widely used psychoactive substance in the world.

History & Background

Caffeine has been consumed for thousands of years through beverages like coffee and tea. Its stimulating effects made it popular across cultures for improving alertness and reducing fatigue.

Chemical Structure & Properties

• IUPAC name: 1,3,7-trimethylxanthine
• Molecular formula: C₈H₁₀N₄O₂
• Molar mass: 194.19 g/mol
• Class: Methylxanthine alkaloid

Mechanism of Action

Caffeine works by:

• Blocking adenosine receptors in the brain
• Reducing feelings of drowsiness
• Increasing alertness and concentration

It also increases dopamine and adrenaline release.

Effects on the Body

• Increased alertness and focus
• Reduced perception of fatigue
• Increased heart rate
• Mild diuretic effect

Common Uses

• Improving mental alertness
• Enhancing physical performance
• Relief of headache (with analgesics)
• Reducing sleepiness

Safe Dosage

Adults: Up to 400 mg/day (generally safe)

One cup of coffee: ~80–100 mg

⚠️ Excess intake may cause jitteriness and insomnia.

Side Effects

• Anxiety
• Insomnia
• Palpitations
• Gastric irritation

Dependence & Withdrawal

• Headache
• Fatigue
• Irritability

Frequently Asked Questions

Is caffeine addictive? – Mild dependence possible.

Is it safe daily? – Yes, in moderation.

Does it improve focus? – Yes.

Is caffeine a drug? – Yes, a psychoactive stimulant.

⚠️ Educational content only. Not a substitute for professional medical advice.