The cannabis plant is far older than people: its ancestors split from hops about 28 million years ago, most likely on the northeastern Tibetan Plateau. People started growing it much later, about 12,000 years ago in East Asia, and the oldest chemical proof of anyone getting high from it is roughly 2,500 to 2,800 years old.
So the answer depends on what you mean by “old.” The species is ancient, farming it is a Stone Age story, and smoking it for its effects is, as far as the evidence shows, an Iron Age habit. This page covers the plant’s own age. For the human story, from Neolithic China to the United Nations, see our history of marijuana.
How Old Is Cannabis? The Timeline at a Glance
| When | What happened | Evidence |
|---|---|---|
| ~28 million years ago | Cannabis and hops (Humulus) split from a common ancestor | Fossil pollen and divergence estimates (McPartland et al., 2019) |
| ~6 million years ago | Cannabis reaches Russia and Europe | Fossil pollen (McPartland et al., 2019) |
| ~1.2 million years ago | Cannabis reaches eastern China | Fossil pollen (McPartland et al., 2019) |
| ~12,000 years ago | People in East Asia domesticate cannabis | Genomes of 110 plants (Ren et al., 2021) |
| ~4,000 years ago | Fiber hemp and drug-type plants start to diverge | Same genomic study |
| 8th century BCE | Burned cannabis residue on a shrine altar at Tel Arad, Judah | Residue analysis (Arie et al., 2020) |
| ~2,700 years ago | A large cannabis cache buried in a Yanghai tomb near Turpan, China | Chemical and genetic tests (Russo et al., 2008) |
| ~500 BCE | Cannabis burned in braziers at Jirzankal Cemetery, Pamir Mountains | Chemical residue (Ren et al., 2019) |
Where and When Did the Cannabis Plant Evolve?
Cannabis belongs to the Cannabaceae family, and its closest living relative is hops, the genus Humulus that flavors beer. The two lineages split about 28 million years ago.
Pinning down where that happened is hard because cannabis leaves almost no fossils. Pollen survives better, but cannabis pollen looks nearly identical to hop pollen. In a 2019 study in Vegetation History and Archaeobotany, John McPartland of the University of Vermont, William Hegman and Tengwen Long reviewed 155 fossil pollen studies from across Asia. They sorted the grains by the plants found alongside them: pollen next to woodland species was counted as hops, and pollen next to steppe plants such as Artemisia (sagebrush) was counted as cannabis, because cannabis prefers open, dry steppe.
Their answer: the “centre of origin” was the northeastern Tibetan Plateau, “in the general vicinity of Qinghai Lake,” a lake about 3,200 meters (roughly 10,500 feet) above sea level. From there, they concluded, cannabis spread west to Russia and Europe by about 6 million years ago and east to eastern China by about 1.2 million years ago.
Treat that as the best current hypothesis, not a closed case. The authors themselves note that cannabis taxonomy and its origin remain debated, and the method depends on inferring which grains are cannabis from their neighbors.
When Did People Start Growing Cannabis?
For millions of years cannabis was a wild steppe plant. Farming began only about 12,000 years ago. A 2021 study in Science Advances sequenced 110 cannabis genomes from around the world and traced every modern hemp and marijuana variety to a single domestication in East Asia in early Neolithic times (Ren et al., 2021). For most of the next 8,000 years, people grew it as an all-purpose crop for fiber, seed and oil.
Around 4,000 years ago, according to the same study, breeding began to pull the plant in two directions: tall, fibrous hemp on one side and resin-rich drug types on the other. That split is the reason hemp and marijuana are the same species but very different plants. Our guide to the many uses of hemp covers the fiber side.
How Old Is the Oldest Evidence of Getting High?
Drug use leaves fewer traces than rope or seeds, so the dates here are much younger:
- Tel Arad, Judah, 8th century BCE. Researchers found burned cannabis residue on one of two altars at a shrine in the Kingdom of Judah (Arie et al., 2020).
- Yanghai Tombs, near Turpan, China, about 2,700 years ago. A grave held a large stash of cannabis. Chemical and genetic tests showed it came from plants with psychoactive potential, and the authors described it as the oldest documentation of cannabis as a pharmacologically active agent (Russo et al., 2008, Journal of Experimental Botany).
- Jirzankal Cemetery, Pamir Mountains, about 500 BCE. Wooden braziers from funerals held residue of cannabis with high levels of psychoactive compounds, the clearest early proof that people burned it for its effects (Ren et al., 2019).
Earlier use is likely but unproven. Claims that people “smoked weed 10,000 years ago” mix up the age of hemp farming with the age of getting high.
How Long Does a Single Cannabis Plant Live?
Not long. Cannabis is an annual: each plant sprouts, grows, flowers, sets seed and dies within one growing season, and the switch to flowering is triggered mainly by longer nights. Growers harvest before the plant finishes setting seed. The cannabis plant life cycle guide walks through each stage. So while the species is about 28 million years old, each individual plant lives only a single season.
Why the Plant’s Age Matters Today
The long history explains a lot about the cannabis on dispensary shelves. Millions of years on cold, dry steppe shaped a hardy, fast-cycling annual. Thousands of years of farming split it into hemp and marijuana. Only in the last century did breeders push THC to modern levels, and the U.S. went from a colonial hemp crop to federal prohibition in between, a story told in our history of marijuana in the U.S..
How Old Is Cannabis? FAQ
How old are marijuana plants in history?
The cannabis lineage is about 28 million years old, dating to its split from hops. People domesticated it about 12,000 years ago, and the oldest chemical evidence of using it to get high is about 2,500 to 2,800 years old.
Where did the cannabis plant first grow?
Most likely on the northeastern Tibetan Plateau near Qinghai Lake, according to a 2019 review of 155 fossil pollen studies. It is a well-supported hypothesis rather than a settled fact.
Is cannabis older than humans?
Yes, by tens of millions of years. Cannabis split from hops about 28 million years ago, long before the first humans.
When did humans start smoking weed?
The oldest firm evidence is burned cannabis residue at Tel Arad in the 8th century BCE and at Jirzankal Cemetery in western China around 500 BCE. Earlier use is possible, but no proof has been found.
Are hemp and marijuana the same plant?
Yes. Both are Cannabis sativa. Genomic research shows fiber and drug types began to diverge about 4,000 years ago through human breeding.
How long does a cannabis plant live?
One season. Cannabis is an annual that grows, flowers, sets seed and dies within a single growing season.
For adults 21+ in legal states. General information, not legal or medical advice.
