Zygophyllaceae
Larrea tridentata
Chaparral · Creosote bush · Greasewood
- Part used
- leafaerial
- Native range
- The deserts of the southwestern United States and northern Mexico
- Morphology
- An evergreen desert shrub to three metres with small resinous olive-green leaves in pairs and yellow flowers. Smells strongly of creosote after rain, which is what names it.
What is in it
Evidence
No supported use. Nordihydroguaiaretic acid was formerly used as a food antioxidant and was removed from the approved list after toxicity findings.
Safety
Hepatotoxic. A cluster of serious liver injuries in the United States in the early 1990s, including cases requiring transplant, led the FDA to warn against it and manufacturers to withdraw products. Kidney injury is also reported. Long traditional use in the desert southwest did not surface this, because the traditional preparations and durations were different from capsule supplementation.
Interactions: Additive liver risk
Regulatory: FDA warning issued; not a permitted ingredient in Australia.
Historical use
Used by Tohono O’odham, Pima and other peoples of the Sonoran and Chihuahuan deserts for a wide range of complaints. Promoted from the 1960s in the United States as a cancer remedy and general tonic.
Recorded as history and attributed where possible. Long use establishes that a plant was widely used, not that it worked, and not that it was safe.
Worth knowing
Creosote bush is among the oldest living things on earth. A clonal ring in the Mojave known as King Clone has been estimated at around eleven thousand years old, growing outward from a single original seedling that germinated not long after the last ice age.
Its medical story is the familiar one in this collection, and it is worth stating carefully out of respect for the traditions involved. Desert peoples used it in specific preparations for specific purposes over a long period without an epidemic of liver failure. The American supplement market sold it as capsules for daily long-term use as a cancer remedy, and produced a cluster of hepatotoxicity serious enough to require transplants.
The plant did not change. What changed was the dose, the duration, the preparation and the reason — which is the single most repeated finding across all one hundred and fifty entries here.
Nomenclature verified against GBIF backbone taxonomy.