Hair from a 2,800-year-old Siberian tomb points to the oldest known cannabis high

Braided human hair from a princely tomb in southern Siberia carries chemical traces of cannabis, and the same grave held close to a thousand cannabis seeds laid down with the dead. Together, the hair and the seeds are the oldest directly dated evidence that people used the plant to get intoxicated, some twenty-eight centuries ago, according to an international team led by archaeologist Gino Caspari of the University of Bern.

That pushes the record back by roughly three hundred years, past a famous cemetery in the Pamir mountains of western China. It also turns an old Greek travel story about the Scythians, the horse-riding nomads of the Eurasian steppe, into something that can be tested in a laboratory. Not everyone is convinced the test was good enough: a forensic toxicologist who was not involved in the study calls the central hair evidence weak.

The tomb is Tunnug 1, a monumental burial mound in the Uyuk Valley of the Republic of Tyva, also spelled Tuva, a Russian region on the northern border of Mongolia. It belonged to high-ranking members of early Scythian society, and it is one of the oldest monumental tombs known from that culture. At its centre, archaeologists found four wooden structures holding log coffins. Horse skeletons had been arranged on top of them, and scattered human bones suggest that people were sacrificed along with the animals.

“The seeds show that cannabis played an important role in the rituals surrounding the burial,” Caspari said in the university’s statement. The hair is what turns that ritual into a claim about drug use. “It’s only so often as an archaeologist that you do get to drug test a person that’s been dead for almost 3,000 years,” he told the Associated Press.

How they found a drug in hair this old

Seeds alone prove very little. Cannabis has been grown for fibre, rope and seed oil for thousands of years, so a pile of seeds in a grave could mean food, an offering or a crop with no psychoactive role at all. The team needed evidence from inside a body.

The plant remains came first. Excavators picked out 243 whole seeds by hand and recovered another 722 complete seeds and 516 fragments by flotation, a technique in which soil samples are soaked in water so that light organic material floats free. Almost all the plant material from the tomb turned out to be cannabis, with only a few seeds from other wild species. Six seeds, including two from the log coffin of the individual catalogued as skeleton 139 and two from that of skeleton 135, were radiocarbon dated. The results place them in the early eighth century BC, matching the period when the tomb was built.

The hair came from the central burial chamber. The team analysed several samples with high-resolution mass spectrometry, which sorts molecules by mass with enough precision to pick out specific compounds at trace levels. Several samples gave clear signals consistent with cannabinol, or CBN, a compound that forms when THC, the main intoxicating ingredient of cannabis, breaks down by oxidation. Weaker signals matched the mass of THC itself.

“The molecular traces in the hair and the cannabis seeds come from the same grave and suggest that cannabis was used for its intoxicating properties,” Caspari said. The authors go further on the ritual context. The tradition of human sacrifice, they write, “would have potentially made the plant a useful agent to calm individuals who were to be included in the rituals.” That is an interpretation, not a measurement, and the paper offers it as a possibility.

Herodotus, braziers and a three-century jump

The Greek historian Herodotus described the Scythians in the fifth century BC. In his account, they crawled into felt tents, threw hemp seeds onto red-hot stones and howled with delight at the vapour. For a long time that passage was the main evidence for Scythian cannabis use, and historians treated it with caution because Herodotus also reported plenty of hearsay.

Archaeology later backed him up. In the Pazyryk burial mounds of the Altai mountains, several centuries younger than Tunnug 1, Soviet excavators found bronze cauldrons filled with stones and hemp seeds next to tent frames, a kit that matches the description almost exactly. At the Jirzankal cemetery in the Pamirs, chemists detected cannabinoid residues in wooden braziers dated to around 500 BC. Later sites in Central Asia also show residues in vessels and on heated stones, which points clearly to inhalation.

Tunnug 1 is older than all of them, and it adds something those sites lack: traces in the human body rather than on equipment. “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,” Caspari told the AP. The plant itself is far older as a crop. The study notes that cannabis was grown as an oilseed crop in East Asia about six thousand years ago, so the question has never been when people met the plant. What scientists cannot pin down is when they discovered what it does to the mind.

What the hair evidence does not settle

The weakest link is also the most important one. Volker Auwärter, head of forensic toxicology at the University Medical Center Freiburg in Germany, who was not involved in the research, told the AP that the hair analysis “is scientifically weak” and that there is not enough evidence to show cannabis was consumed. “For a central part of the study, the article falls far short of what would have been possible,” he wrote, adding that the hair data carry the abstract’s main claims.

His main objection is contamination. Hair buried for millennia in a grave full of cannabis could pick up cannabinoids from its surroundings, from smoke in the air or from plant material decaying next to it. In modern drug testing, laboratories separate use from exposure by looking for THC-COOH, a compound the body produces only after THC has been absorbed. CBN and THC can reach hair from outside, so their presence alone does not prove that anyone ingested the drug. Auwärter said a test involving forensic toxicology expertise would have been advisable and easy to arrange.

The authors acknowledge other limits themselves. The hair results cannot say how much cannabis was consumed, and they cannot tell inhalation from eating or drinking. The seeds probably came from wild plants, so there is no way to know how potent they were or whether anyone selected them for higher THC. The abstract suggests that some wild populations in Eurasia may have been naturally stronger, which remains a hypothesis. And the sacrifice interpretation rests on context, not on any test of the sacrificed people.

There is also the question of whose hair it was. Sampling came from the central chamber, which held the most important burials, so the results speak to elite funerary practice, not to everyday life on the steppe.

Common questions about ancient cannabis use

How long have humans used cannabis as a drug?

The oldest directly dated evidence now comes from Tunnug 1 in southern Siberia, about 2,800 years ago, if its hair analysis holds up. Before this study, the earliest firm chemical evidence was from braziers at the Jirzankal cemetery in western China, about 2,500 years old. People grew cannabis for seeds and fibre thousands of years earlier.

Who were the Scythians?

The Scythians were mounted nomads who spread across the Eurasian steppe from southern Siberia to what is now Ukraine during the first millennium BC. They are known for elaborate burial mounds, horse sacrifices and gold work in the so-called animal style. Greek writers, Herodotus above all, described their customs, including inhaling hemp smoke.

Can hair really show drug use after thousands of years?

Hair can preserve chemical compounds for a very long time when burial conditions are right, and hair from Andean mummies has been tested for coca, for example. The difficulty is proving that a compound entered the body rather than settling on the hair from outside. That is why critics of the Tunnug 1 study want markers that only form inside the body.

What is cannabinol (CBN)?

Cannabinol is a compound that forms when THC, the main psychoactive ingredient in cannabis, oxidises and breaks down over time. Because THC itself degrades, CBN is often what remains in old samples, which makes it a useful marker in archaeology and in aged cannabis products.

What comes next at Tunnug 1

The team is already working on the plant DNA. “We have already begun sequencing some of the plant samples,” Caspari said. “DNA preservation is excellent in this case. This will help us learn more about the history of the domestication and spread of this crop soon.” Genetic data could show whether the Tunnug seeds came from wild stands or from cultivated plants, and how they relate to East Asian lineages.

Excavations at Tunnug 1 began in 2017, with team members from Germany, Russia, Sweden and Switzerland. An earlier publication from the site reported 18 horses arranged on the mound; several dozen more horse sacrifices have been uncovered since. The study was published in Science on 5 November 2026.

Reference: Caspari et al., “Direct evidence for psychoactive cannabis use 2800 years ago,” Science, 2026. DOI: 10.1126/science.aeg3800

Tags: archaeology, cannabis, Scythians, Siberia, THC, Tunnug 1