Osha comes from the root of *Ligusticum porteri*, a plant used in some Native American and other traditional herbal practices. Modern human studies are missing, so claims about health benefits lack reliable backing.
People take osha as a tea, tincture, or capsule, often for respiratory complaints. These traditional uses lack clinical proof and do not represent confirmed effects. Early lab work has catalogued compounds in osha, but that work does not establish safety or usefulness in people.
Safety flags stand out. Furanocoumarins and alkaloids in the plant can harm the liver. Osha also raises sun sensitivity and may interfere with blood thinners. Avoid it during pregnancy and breastfeeding.