Siberian burial site yields oldest evidence of psychoactive cannabis use

A 2,800-year-old Scythian burial mound in Siberia's Uyuk Valley has produced the earliest direct evidence of cannabis consumed for its mind-altering effects. Researchers found over 1,400 cannabis seeds and detected THC in human hair from the tomb, predating previous evidence by centuries.

A Siberian burial mound from the ancient Scythian culture dating to 2,800 years ago has yielded the oldest-known evidence for the use of cannabis for its mind-altering effects. Scientists found its seeds among the grave goods and human hair bearing chemical signatures of THC inside the tomb. The study, led by archaeologist Gino Caspari of the University of Bern and the Max Planck Institute of Geoanthropology, was published in the journal Science.

The evidence was unearthed in a monumental burial structure around 460 feet (140 metres) in diameter, located in the Uyuk Valley of Russia's remote Republic of Tyva. The tomb in southern Siberia was the last resting place of high-ranking members of Scythian society, known for their horseback warfare, gold craftsmanship, and nomadic lifestyle across the Eurasian steppe.

Researchers recovered more than 1,400 cannabis seeds associated with burials inside the tomb and used scientific dating to trace their age to the early 8th century BC. Chemical analysis of braids of hair from several bodies in the central burial chamber identified signatures consistent with THC, the psychoactive compound in cannabis, and traces of cannabinol.

“The human body does build cannabis-related molecules like THC and CBD into the hair. That's how drug tests work,” Caspari said. “We cannot really say how they consumed it based on the hair alone, but considering later evidence in the region it seems likely that it was inhaled.” The discovery predates the oldest previous evidence for mind-altering cannabis use, such as implements for burning it from the Middle East and the Pamir Mountains in Central Asia.

The seeds were in a good state of preservation, and researchers have begun sequencing them. “That's even rarer than having plant remains themselves, and it is currently the oldest cannabis DNA known,” Caspari said. “I think over the coming years we will be able to add details and partially rewrite the domestication history of this important crop.”

The burial mound was constructed using larch tree logs and clay, encased in thousands of tons of stones. On the mound’s surface, the Scythians apparently performed animal sacrifices of dozens of horses and probably also of people, considering scattered human bones found among the remains. Caspari noted that the Scythians came into contact with ancient Greece, and the 5th century BC historian Herodotus described similar rituals. “After finding the remains in southern Siberia, we know that at least some of his descriptions about the steppe peoples had some truth,” Caspari said.