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Limited evidenceImmunity

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.

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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.

How to take it

TimingTiming does not matter.
With food?Either way.
Worth knowingNever wild-harvest it: osha grows alongside poison hemlock and water hemlock, and the roots are hard to tell apart.

Frequently asked questions

Does osha root work for colds and sore throats?

There is no evidence that osha root helps colds or sore throats; its grade is limited. No human trial of osha exists for any condition, and the published research is limited to animal and cell-culture work.

Is osha root safe?

Osha root has no human safety data, and wild-harvested material is a real risk because osha grows alongside lethally toxic poison hemlock and water hemlock, whose roots look similar. Use only reputable commercial sources, and avoid osha in pregnancy and while breastfeeding.

How much osha root should I take?

No studied dose of osha root exists. Product labels typically suggest 500 mg of dried root, or 20–40 drops of tincture, up to three times daily.

Scientific references

Related in Immunity

Herbal medicines: what the evidence says (335)