What are the short-term and long-term effects of caffeine?
Caffeine takes about an hour to affect you (less on an empty stomach), and usually lasts 4-6 hours. Because caffeine is a stimulant, most people experience increased alertness, blood pressure, and breathing rate. These effects are mostly due to caffeine increasing your metabolic rate (though it has not been linked to weight loss). The drug is a diuretic, causing increased urination which can lead to dehydration. Caffeine makes many people feel jittery, “on edge,” and unable to sleep. Long-term use can lead to nervousness, insomnia, dehydration, stomach irritation, and fatigue.
