The chance discovery of a cow horn container in a rock shelter in South Africa’s Eastern Cape Province has provided scholars with the recipe for a pharmaceutical compound formulated around 500 years ago. The cow horn, which has been radiocarbon dated to between 1461 and 1630, was found covered with a leather lid and wrapped in leaves and grass. A team led by University of Johannesburg archaeologist Justin Bradfield analyzed residues from the container. They concluded that the residues contained high concentrations of the chemical compounds mono-methyl inositol and lupeol, both of which are used to control blood sugar and cholesterol levels, lower fevers and soothe inflammation, and treat infection. The team determined that three local plants could have been the source of the chemicals. Bradfield says the container is the earliest evidence from southern Africa of people combining two or more plants for the purposes of medicinal treatment. “We know that for tens of thousands of years people have understood the medicinal and toxicological properties of plants,” he says. “But until now we haven’t had tangible evidence that they were combining extracts from several plants to create a medicinal recipe.”