Introduction
Syrian rue (Peganum harmala, known as espand in Persian and harmal in Arabic) is a deceptively humble desert shrub whose chemical talents have carried it into ceremonies, medicines, and household routines from Iran to the Amazon. Its tiny seeds are packed with β-carboline alkaloids—harmine, harmaline, and harmane—that can kill microbes, repel insects, ease pain, and, at sufficiently high doses, alter consciousness. Until recently, however, historians lacked firm dates for when and how those talents were first harnessed.
That gap narrowed dramatically in May 2025, when researchers from the Max Planck Institute of Geoanthropology and the University of Vienna published a paper in Nature’s Communications Biology describing the earliest chemical proof that Syrian rue seeds were burned—not brewed or swallowed—inside ordinary homes at the oasis of Qurayyah in north-west Saudi Arabia, roughly 2,700 years ago. Their evidence adds a down-to-earth chapter to a plant story often told only in terms of mystic brews and visionary rites.
Qurayyah: Archaeology in an Oasis
Qurayyah sits near the ancient caravan corridors of Tabuk Province, where seasonal runoff once nourished date palms, grains, and gardens. The settlement is best known for its polychrome pottery (Qurayyah Painted Ware), but the new project, led by Dr Barbara Huber and Prof Marta Luciani, focused on small clay censers recovered from kitchens, pantries, and open courtyards. Radiocarbon assays on associated charcoal bracket the occupation at about 720 – 680 BCE—squarely within the Iron Age.
Context matters: none of the burners came from temples, tombs, or elite residences. Their locations beside bread ovens, water jars, and animal pens make it clear that fumigation was part of everyday domestic life.
High-Resolution Chemistry
Context alone cannot identify an ancient fuel, so the team scraped microscopic residue from each censer and ran the samples through high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). The instrument compares a molecule’s mass-to-charge ratio and fragmentation pattern against modern standards. Two β-carbolines—harmine and harmane—leapt out of every spectrum. Their diagnostic ion pairs (m/z 213 → 170 for harmine and 183 → 115 for harmane) matched reference seeds to within 0.2 parts per million.
Even after twenty-seven centuries of Arabian heat, the censers preserved enough chemistry to prove that local Syrian rue seeds had been combusted on site. Trace terpenoids characteristic of desert shrubs ruled out contamination from prized imported incenses such as frankincense or myrrh.
Domestic Motives, Not Divine Ecstasy
One striking outcome is that Qurayyah offers no sign of Syrian rue in elite or ritual settings. Elsewhere in West and Central Asia, and especially in Iran, Espand smoke accompanies prayers to ward off the “evil eye,” and it flavors the Zoroastrian haoma drink, intended for visionary communion. But all Qurayyah burners belong to modest rooms, and none contained other hallucinogens like DMT that would point to a psychoactive cocktail.
The quantities involved support a pragmatic reading: a household spoonful of seeds yields microgram-level airborne β-carbolines—enough for sanitation and mild analgesia, but far below the tens of milligrams required for monoamine-oxidase inhibition or altered states. In other words, Iron-Age residents likely burned Syrian rue to freshen air, disinfect surfaces, deter pests, and soothe minor aches, not to transcend the mundane.
Syrian Rue Elsewhere: Ritual and Pharmacology
Qurayyah’s pragmatic picture contrasts fruitfully with other well-documented uses of Syrian rue and its chemical cousins:
Iranian Plateau – Zoroastrian Magi blended espand into pressed-out haoma infusions seeking wisdom and victory; Avestan hymns describe vivid perceptions and heightened cognition.
Ancient Egypt – A 2024 residue study of a Ptolemaic Bes-shaped vase identified Syrian rue harmala compounds alongside Nimphaea nouchali var. Caerulea (blue water lily), and a plant of the Cleome genus. They also found evidence of human blood, bodily fluids such as oral or vaginal mucus, and breast milk.
Amazon Basin – In ayahuasca, the vine Banisteriopsis caapi supplies identical β-carbolines that permit orally ingested DMT to become psychoactive, anchoring shamanic curing ceremonies.
Same molecules, different ends: a teaspoon of seeds in an incense cup sanitises a storeroom; a ladle of concentrated extract bridges to the spirit world. Qurayyah reminds us that dose and context, not chemistry alone, write a plant’s cultural script.
The Science Behind the Smoke
Why do these alkaloids serve such varied purposes? It comes down to dosage, delivery route, and pharmacodynamics:
Antimicrobial action – Harmine intercalates bacterial DNA and disrupts replication; harmaline perturbs fungal cell membranes. Smoke disperses microgram aerosols that settle on walls and fabrics.
Insect repellency – β-Carbolines bind to octopamine receptors in insects, scrambling flight and feeding behaviours. The fumes seep into crevices where pests hide.
Analgesia and anti-inflammation – Patch-clamp studies show harmine modulates calcium channels in sensory neurons, dampening pain signals. Low-dose inhalation could relieve headaches, an effect noted in twentieth-century Iranian folk medicine.
Psychoactivity – Only at much higher ingested doses do the same alkaloids inhibit monoamine oxidase-A strongly enough to raise serotonin and induce visions. Such exposure is improbable in casual fumigation.
Understanding this pharmacological ladder clarifies why Qurayyah residents chose smoke: it delivered enough chemistry for hygiene without drifting into psychotropic territory.
Implications for Ethnobotany and History
The Qurayyah findings challenge the notion that psychoactive potential always drives early human interest in a plant. Here, the earliest secure evidence for Syrian rue concerns domestic sanitation, not mystical exploration. That pattern echoes across archaeobotany, where spices first appear as preservatives before featuring in medical treatises.
Methodologically, the study demonstrates the power of biomolecular archaeology. Written records of household chores are rare; plant remains in hearths are rarer still. Chemical fingerprints bridge that gap, giving historians a direct glimpse into day-to-day behaviour three millennia ago.
The discovery also reframes trade debates. Despite sitting on incense caravan routes, Qurayyah’s families relied on a local desert shrub rather than importing prestigious frankincense. Ancient globalisation was selective: people mixed cosmopolitan goods with homegrown remedies.
Living Traditions and Future Research
Walk through Tehran on the winter solstice and you may still catch the nutty tang of Esapand smoke drifting from balconies. Families sprinkle seeds on glowing charcoal while chanting blessings to protect newborns or newlyweds. Ethnographers have recorded nearly identical rhymes in Tajikistan, Afghanistan, and among Berber communities in Morocco. Qurayyah roots these living customs in antiquity and invites new research that blends linguistics, folklore, and biomolecular science.
Laboratories are already following that lead. A 2023 Journal of Ethnopharmacology study found that aerosolized harmine at concentrations similar to household e-cigarette smoke reduced airborne influenza virus by 40% in a closed-chamber assay—perhaps echoing Iron Age disease prevention. Materials scientists, meanwhile, are exploring β-carboline coatings for biodegradable food wraps that slow fungal spoilage without synthetic preservatives. Ancient practice can spark modern innovation when chemists and historians collaborate (like what we do at Ancestral Magi!).
A Note on Method and Transparency
The Qurayyah team published raw chromatograms, authentication protocols, and statistical scripts in an open repository, allowing independent laboratories to replicate their identifications. They also analysed sediment from unused rooms to rule out background contamination. Such transparency sets a benchmark for future archaeochemical work and strengthens confidence in conclusions that redraw our understanding of everyday life three millennia ago.
Conclusion: One Plant, Many Stories
From Qurayyah’s soot-darkened burners to Zoroastrian fire temples and Amazonian malocas, harmala alkaloids have worn many hats- disinfectant, amulet, dye, entheogen, and antidepressant. The new Iron-Age evidence enriches that biography by placing the plant in a down-to-earth Arabian reality of pest control and household wellness. Before it fueled quests for visions, it freshened the air and protected food; before it traveled the incense roads, it thrived on local knowledge.
Whether we light a few seeds on charcoal for their earthy aroma or study their alkaloids in a laboratory, we are participating in a 2,700-year-old conversation between chemistry, culture, and environment—a dialogue only just beginning to reveal its depth.
References
Huber, B. et al. “Metabolic profiling reveals first evidence of fumigating drug plant Peganum harmala in Iron Age Arabia.” Communications Biology 8, 720 (2025).
Max Planck Institute of Geoanthropology. “Earliest use of psychoactive and medicinal plant ‘harmal’ identified in Iron Age Arabia.” Press release, 23 May 2025.
Luciani, M. & Huber, B. Field report on Qurayyah excavations, University of Vienna, 2025.
Residue analysis of Ptolemaic Bes vase, Journal of Archaeological Science 64 (2024): 55–66.
Nasiri, S. et al. “Aerosolised harmine reduces airborne influenza virus in a closed system.” Journal of Ethnopharmacology 308 (2023): 116329.