Hundreds of wild cannabis seeds and strands of preserved human hair from a royal burial mound in southern Siberia point to people using the plant for its mind-altering effects about 2,800 years ago. If the interpretation holds, it would push back the earliest confirmed psychoactive use of cannabis by roughly 300 years.

The findings, published Nov. 5 in the journal Science, come from the Tunnug 1 mound in the Uyuk Valley of the Russian republic of Tuva. Researchers recovered more than 1,000 whole cannabis seeds and about 500 partial seeds from inside the burial structures, and carbon dating placed them between 800 and 760 B.C., according to Live Science.

The key claim rests on the hair — and so does the controversy. Analysis of several samples showed signals matching THC and cannabinol, two compounds tied to cannabis's psychoactive effects. An independent forensic toxicologist has questioned whether that evidence proves consumption, and that debate is central to how the find should be read.

Seeds, Hair and a "Spectral Cavalcade"

Tunnug 1 is one of the earliest monumental tombs associated with the Scythians, horse-riding nomads of the Eurasian steppe. The mound measures roughly 140 meters (about 460 feet) across, ScienceAlert reported, and conceals wooden burial chambers built from larch logs and sealed under thousands of tons of stone.

At its center, archaeologists found four wooden structures holding six elite individuals in log coffins. Horse skeletons were arranged on top, part of a Scythian funeral display researchers call a "spectral cavalcade." Scattered human bones on the mound's surface suggest people may also have been sacrificed.

Lead author Gino Caspari, an archaeologist at the Max Planck Institute of Geoanthropology and the University of Bern, said the combination of evidence is what sets the site apart. "It's extremely rare that we have both preserved plant parts and human soft tissue with the active compounds in it in the same context," he told the Associated Press.

He said the seeds were deliberate grave goods: "they are not there by accident." The research team wrote that the plant may have been used to calm people during sacrificial rites, but Caspari has acknowledged that interpretation is speculative and rests on the burial context rather than direct evidence.

A Wild Steppe Plant With Many Uses

The seeds belong to Cannabis ruderalis, a wild, small-seeded form of the plant that still grows naturally across temperate Central Asia. That suggests the people at Tunnug may have gathered it locally rather than trading for cultivated varieties from warmer regions.

Cannabis likely originated in Asia, where it was grown for rope, textiles and, beginning about 6,000 years ago, as an oilseed crop. Because of those many uses, seeds alone cannot show that anyone got high — a gap that makes the hair evidence so important. The hair is what the team says links the plant to consumption.

The new date compares with earlier evidence from a cemetery in western China dated to about 500 B.C., where residues showed cannabis had been burned. Archaeologists have also found cannabis seeds in tombs across Central Asia's highlands, the AP noted, though seeds by themselves cannot reveal how the plant was used. The Greek historian Herodotus also described Scythians inhaling fumes from burning hemp seeds around 440 B.C., an account scholars have long treated cautiously without physical evidence.

A Toxicologist Calls the Hair Evidence "Scientifically Weak"

Not every expert is convinced. Volker Auwaerter, head of forensic toxicology at the University Medical Center in Freiburg, Germany, who was not involved in the study, told the AP that the hair analysis "is scientifically weak." He argued that "the hair data carry the abstract's main claims," yet do not separate consumption from external exposure.

In other words, hair buried for nearly 3,000 years beside piles of cannabis could have absorbed traces of the plant without anyone ingesting it. Auwaerter said a lab test involving forensic toxicology expertise would have been advisable and easy to arrange.

Elisa Guerra Doce of Spain's University of Valladolid, who studies consciousness-altering substances in European prehistory and was also not involved, reached the opposite view. She credited the authors with showing "cannabis was not merely deposited as a funerary offering but was actually consumed by individuals associated with the burial rite."

The study is peer-reviewed and published in a leading journal. Still, it rests on a single site and a handful of individuals, it cannot establish how much cannabis anyone used or whether it was smoked or eaten, and its strongest claim depends on a method an outside specialist disputes. The safest reading is that the tomb offers the earliest direct evidence suggesting psychoactive use, not settled proof.

Ancient DNA Could Trace How Cannabis Spread

The team is now sequencing DNA from the ancient seeds. "We have already begun sequencing some of the plant samples," Caspari said, with the goal of learning whether the Tunnug plants were wild or cultivated and how cannabis moved across Eurasia.

That genetic work could clarify a broader question for botanists: when wild cannabis populations on the steppe began to be managed by people, and how human selection shaped a plant that is now grown worldwide. The answer could also help explain why this species, unlike many crops, still thrives in the wild across its native range.

The dig, which began in 2017, involved researchers from Germany, Russia, Sweden and Switzerland working for months in remote steppe conditions. Future findings will likely appear as further peer-reviewed papers, and independent toxicology testing of the hair would be the most direct way to resolve the debate the study has opened.

What Readers Want to Know

What did researchers find in the Siberian tomb? More than 1,000 whole cannabis seeds and about 500 partial seeds dated to 800 to 760 B.C., plus preserved human hair that showed signals matching THC and cannabinol.

Where is the site? The Tunnug 1 royal burial mound is in the Uyuk Valley of Tuva in southern Siberia, Russia, and is linked to early Scythian culture.

Does this prove ancient people got high? Not conclusively. The authors say the hair shows consumption, but forensic toxicologist Volker Auwaerter says the data cannot rule out contamination from cannabis buried alongside the bodies.

How much earlier is this than previous evidence? About 300 years earlier than psychoactive cannabis evidence from a western Chinese cemetery dated to roughly 500 B.C.

What kind of cannabis was it? Cannabis ruderalis, a wild form that still grows naturally across temperate Central Asia.

What comes next? The team is sequencing ancient seed DNA to learn whether the plants were wild or cultivated and how cannabis spread across Eurasia.