- Chumash Indians and other California Indians have used yerba santa (Eriodictyon californicum) and other related species (Eriodictyon crassifolium, Eriodictyon trichocalyx) for many centuries in the treatment of pulmonary (lung) conditions, saliva production, and to stop bleeding of minor cuts and scrapes.
- In the United States and Britain, Eriodictyon californicum was formally used for conditions including influenza, bacterial pneumonia, asthma, bronchitis, and tuberculosis starting in the late 1800s until the 1960s (when drug regulations became more stringent around proof of efficacy). Subsequently, the extracts remained GRAS ("generally regarded as safe") as a flavor for foods, beers, and pharmaceuticals (such as to hide the bitterness of quinine). Eriodictyon plant extracts have also been used in cosmetics.
- Eriodictyon species contain flavones with free radical scavenging (antioxidant) properties, and have therefore been proposed as being beneficial for a number of health conditions. However, there is little scientific study of yerba santa in humans, and effectiveness has not been demonstrated for any specific condition.