The composition of snake oil medicines varies markedly among products.
Stanley's snake oil – produced by Clark Stanley, the "Rattlesnake King" – was tested by the United States government in 1917. It was found to contain
mineral oil
1% fatty oil (presumed to be beef fat)
red pepper
turpentine
camphor
This is similar in composition to modern-day capsaicin-based liniments or chest rubs. None of the oil content was found to have been extracted from actual snakes.
The government sued the manufacturer for misbranding and misrepresenting its product, winning the judgment of $20 against Clark Stanley. Soon after the decision, "snake oil" became synonymous with false cures and "snake-oil salesmen" became a tag for charlatans.
