According to Snopes, combining paracetamol — a fever reducer and pain reliever found in aspirin — and Coca-Cola makes for an effective hangover cure. Individually, the paracetamol acts to ease the headache while the Coca-Cola rehydrates the body. When combined, the caffeine found in Coca-Cola boosts the effects of paracetamol.
Urban legends caution that taking paracetamol with Coca-Cola works as a homemade aphrodisiac or drug. Snopes traces the origins of this myth back to the 1930s, when a cautionary article appeared in the Journal of the American Medical Association warning that teenagers were dissolving pills in their sodas to create an intoxicating and addictive drink explicitly compared to narcotics. This claim had little scientific research or merit, but the idea took hold and resurfaces periodically, usually in high schools. The urban legend even had a brief cameo in the 1978 movie "Grease," when mention is made of its supposedly aphrodisiac qualities. Snopes dismisses any anecdotal evidence of this as an example of the startling power of psychosomatic behavior. The power of this adolescent mythology stems from its associations with inebriation and sexual activity. Coupled with the belief that two household items can be combined to form a transgressive and subversive substance, the myth of Coca-Cola and paracetamol continues to persist even after being thoroughly debunked.