Ericaceae
Arctostaphylos uva-ursi
Bearberry · Uva-ursi · Kinnikinnick
- Part used
- leaf
- Native range
- Circumboreal — northern North America, northern Europe and Asia
- Morphology
- A low mat-forming evergreen shrub with small leathery spoon-shaped leaves, pink urn flowers and red berries. Both the Latin and the Greek-derived names mean bear-grape.
What is in it
Evidence
Arbutin is hydrolysed to hydroquinone, which has genuine antibacterial activity in urine. Trials are few and small; the EMA permits it as a traditional-use registration for uncomplicated urinary complaints with a strict duration limit.
Safety
Hydroquinone is the concern. Prolonged use risks liver toxicity and, at high exposure, retinal changes. Regulators limit use to short courses — the EMA specifies no more than a week at a time and not more than a few times a year. Very high tannin content causes gastrointestinal irritation. Contraindicated in pregnancy and in children.
Interactions: Reduces absorption of drugs taken concurrently through tannin content
Regulatory: EMA traditional-use registration with a duration limit. Permitted in Australia as a listed ingredient.
How the traditions classify it
Three systems, rating the same plant. Where they disagree, none of them is correcting the others — they are separate frameworks that arrived at their categories independently.
Historical use
Used across the northern hemisphere by many peoples — the Algonquian name kinnikinnick refers to smoking mixtures containing it, and its urinary use appears independently in European and North American traditions.
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
Bearberry is one of the few herbs where regulators have set an explicit duration limit rather than a dose limit, and the reason is worth understanding.
Arbutin is inert until the body hydrolyses it to hydroquinone. Hydroquinone is antibacterial in urine, which is why the plant works at all, and it is also a compound with genuine toxicity on repeated exposure — it is restricted in skin-lightening cosmetics for the same reason.
So the European guidance is not "take this much" but "for no more than about a week, and not more than a few times a year". That shape of restriction — safe briefly, unsafe cumulatively — is one this collection keeps encountering, and it is the shape that traditional practice is least equipped to detect.
Nomenclature verified against GBIF backbone taxonomy.