Osha Root
A Rocky Mountain root used in Native American and herbalist traditions for coughs and sore throats. The published science is entirely preclinical — no human trial of osha exists for any condition.
Evidence last reviewed: August 2026
What the science says
- No human studies at all Limited evidence
PubMed indexes no clinical trial of osha for respiratory infection or any other indication. The published pharmacology is limited to animal work, such as a study reporting antinociceptive activity of root preparations and isolated phthalides in mice.
- Cell-culture activity only Limited evidence
Root extract has been shown to affect human promyelocytic leukemia cells in vitro. This is a cell-culture observation with no bearing on colds, cough or immune function in people.
Dosage & safety
Studied doseNo studied dose exists. Product labels typically suggest 500 mg of dried root, or 20–40 drops of tincture, up to three times daily.
SafetyOsha belongs to the carrot family, which contains lethally toxic look-alikes such as poison hemlock — wild-harvested material is a genuine risk and only reputable commercial sources should be used. Avoid in pregnancy (traditionally regarded as a uterine stimulant) and while breastfeeding. Wild populations are heavily over-harvested and cannot be cultivated easily.
Scientific references
Where to buy
Referral link — this site may earn a commission on purchases.
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