It is widely applied as a stimulant in beverages (coffee tea energy drinks) pharmaceuticals (headache remedies alertness aids) and as a flavoring agent in foods and cosmetics.

Its primary purpose is antagonizing adenosine receptors to promote alertness reduce fatigue enhance physical performance and provide mild analgesic and diuretic effects.

Caffeine (CHNO CAS 58-08-2) is a naturally occurring xanthine alkaloid appearing as white silky crystals or powder with a sublimation point of 178C melting at 234-236.5C density of 1.23 gcm and solubility of 20 gL in water at 20C.