Analysis of Inca mummies identifies the drugs used in their most important sacrificial ritual

Analysis of Inca mummies identifies the drugs used in their most important sacrificial ritual Swati Mestri Scientific Editor Robert Egan Senior Editor Archaeologists have performed toxicological analysis on the mummified remains of people sacrificed at mountain shrines across the Inca Empire, revealing the psychoactive substances they consumed before their deaths. One of the most sacred rituals in the Inca Empire was the capacocha, during which children and young women were sacrificed as an act of veneration for important deities, becoming intermediaries between living people and the divine. As part of these rituals, the individuals were often given psychoactive substances, possibly as a perceived means to enhance their prophetic abilities. While the use of psychoactive plants by the Incas is recorded in historical accounts, relatively little is known about the substances consumed during the capacocha. "Earlier analyses either produced negative results or focused primarily on coca leaves," explains the study's lead author, Dr. Dagmara Socha of the University of Warsaw. The preserved bodies of the sacrificed people provide a unique opportunity to investigate this, as chemicals become embedded in the keratin structures of the hair and nails, making them identifiable by toxicological analysis. Tracing substances in eight mummies "Our aim was to identify a broader range of psychoactive substances administered to the children and to determine whether patterns in their use could provide new insights into how capacocha ceremonies were conducted at different locations," says Socha. "Recent advances in toxicology now allow for the identification of low concentrations of such substances." The research team performed toxicological analysis on hair and nail samples from eight mummies from several mountains in Peru and Argentina, representing a wide range of sacrificial practices across the Inca Empire. Their results are published in the journal Antiquity. In all the mummies, they identified cocaine, confirming that the individuals all chewed coca leaves. Coca leaves played an important role in religious beliefs as offerings to the gods, but also could have been a means to help reduce altitude sickness and fatigue during the children's long, arduous journeys up the mountains. In four mummies, they also found evidence of alcohol consumption, possibly from the corn beer chicha, which is known from historical records to have been given to the children to dull their senses and calm them during the final stage of the ritual. Harmine points to local ritual differences "One of the most intriguing findings concerns the famous Lady of Ampato, also known as Juanita, in whom we detected traces of harmine," Socha adds. "Harmine is an alkaloid associated with Banisteriopsis species, one of the principal plants traditionally used in the ayahuasca beverage. It may indicate that a harmine-containing beverage had a specific role in ceremonies connected with this particular sacred mountain." These findings indicate that there were distinct differences between the substances given to each sacrificed individual, suggesting significant variation in how the capacocha was performed across the empire. Ritual practices appear to have been adapted to local religious traditions and to the deities or sacred places involved. "Five hundred years after these children were sacrificed during one of the most important Inca rituals, new technologies are allowing us to uncover details of their lives and Inca religious practices," Socha concludes. "What we are seeing is that the capacocha was not a single standardized ritual, but rather the Incas appear to have adapted it to different cults and local religious traditions." Publication details Dagmara Socha et al., Toxicological studies on the Inca frozen mummies from volcanoes in Peru and Argentina. Antiquity (2026). DOI: 10.15184/aqy.2026.10439 Journal information: Antiquity Provided by University of Cambridge