The earliest chemical evidence of cannabis smoking: 2,500-year-old funeral rites in the Pamir Mountains

The Jirzankal Cemetery

The cemetery sits in Tashkurgan Tajik Autonomous County, Xinjiang, in the far west of modern China — a place that 2,500 years ago was a crossroads of civilizations. The Pamir Mountains sit along what would become the Silk Road, connecting Central Asian, East Asian, and Western Asian cultures.

The Chemistry

The Herodotus Connection

The discovery at Jirzankal resonated with one of the most famous passages in ancient literature. Writing around 440 BCE — roughly contemporaneous with the Jirzankal burials — the Greek historian Herodotus described the funeral customs of the Scythians, a nomadic people of Central Asia:

“The Scythians take the seed of this hemp and, creeping under the felt coverings, throw it upon the red-hot stones; immediately it smokes, and gives out such a vapour as no Grecian steam-bath can exceed; the Scythians, transported by the vapour, shout aloud.”

Archaeological excavations of Scythian-associated sites in the Altai Mountains of southern Russia (the Pazyryk culture) had already found cannabis seeds in burial contexts. But Ren's team provided the first direct chemical evidence confirming the practice in a contemporaneous Central Asian population along the Silk Road corridor.

Wild Cannabis vs. Cultivated Cannabis

One of the most important implications of the study is what it reveals about early cannabis cultivation.

Wild Cannabis sativa is primarily a fiber and seed plant. Its THC content is typically very low — well below the threshold for noticeable psychoactive effects. For the Jirzankal braziers to contain high-THC residues, one of two things had to happen: either these people were actively cultivating cannabis and selecting for potency, or they were identifying and harvesting wild populations that naturally produced higher THC.

Two Discoveries, One Story

Ren's Jirzankal finding pairs with a slightly older discovery: Ethan Russo's analysis of a 2,700-year-old cannabis cache from the Yanghai Tombs in Xinjiang, China, found approximately 789 grams of dried cannabis in a shaman's grave. Together, these discoveries paint a picture of a Central Asian corridor — from the Turpan Depression to the Pamir Plateau — where cannabis was cultivated, traded, and used ritually for millennia before the common era.

The broader implication is that cannabis is not a modern drug. It is one of humanity's oldest psychoactive companions — woven into funeral rites, shamanic practices, and trade networks since before recorded history. Every debate about cannabis policy is, in a sense, the latest chapter in a story that began at least 2,500 years ago on a frozen mountaintop along the Silk Road.

Frequently Asked Questions

Is this the oldest cannabis ever found?

No — Russo's 2008 analysis of cannabis from the Yanghai Tombs dates to approximately 700 BCE, roughly 200 years older. But the Yanghai cannabis was a dried cache (stored plant material), while the Jirzankal evidence is residue from cannabis that was actually burned. Ren's finding is the oldest evidence of cannabis smoking specifically — the deliberate combustion of cannabis to inhale its psychoactive smoke.

How do we know they were getting high and not just burning hemp?

The chemical analysis is the key. Wild hemp has very low THC content — typically below 1%. The residues from the Jirzankal braziers showed cannabinoid profiles consistent with high-THC cannabis, particularly elevated CBN (the compound THC degrades into over centuries). If they were burning ordinary hemp fiber, the cannabinoid signature would be different.

Why was cannabis used in funeral ceremonies?

The study doesn't definitively answer this, but the ritual context — braziers placed alongside the dead in grave chambers — suggests the cannabis smoke served a spiritual or ceremonial function. Herodotus described Scythian cannabis rituals as communal experiences of altered consciousness. The Jirzankal evidence aligns with cross-cultural patterns of using psychoactive substances to mark death, facilitate communication with the deceased, or ease grief.

Does altitude really make cannabis more potent?

Yes. Cannabis plants under greater UV stress (found at higher altitudes) tend to produce more cannabinoids, likely as a biochemical defense mechanism. The Jirzankal Cemetery sits above 3,000 meters. Whether the elevated THC in the brazier residues reflects altitude effects, deliberate cultivation, or both remains debated, but the altitude-potency connection is well-documented in modern cannabis botany.