Sassafras is safer without safrole


Sassafras was once one of the largest exports from the U.S. to Europe. Native Americans used the inner root bark of the tree, indigenous to the eastern part of the country, to calm upset stomachs and clear up infections, and some 19th century physicians prescribed it to reduce fevers. The fragrant root bark was also a popular ingredient in soaps, perfumes, foods and drinks -- particularly root beer. In 1960, the FDA banned the food use of safrole -- the main component in sassafras root bark -- when the volatile compound was found to cause cancer in animals.


Uses: Sassafras teas and supplements are used as athletic performance enhancers and detoxifying agents. Oil of sassafras is sometimes applied topically to treat lice.

Dose: Sassafras is most commonly found in herbal and “detox” teas; it’s also sold as a liquid extract, with recommended doses ranging from 3 to 6 milliliters per day. Look for products that are safrole-free.


Precautions: Because of the risk of safrole ingestion, many experts caution against using sassafras supplements internally. Even safrole-free products can quicken heart rate, increase blood pressure and induce fatigue, among other symptoms. Pets and small children are particularly susceptible to the herb’s negative side effects.

Research: In the 1950s and ‘60s, researchers showed that high doses of safrole caused liver damage and liver and lung cancer in mice and rats that were fed the compound for long periods of time. Nursing mice developed tumors when their mothers were given safrole. Because human studies are lacking, researchers don’t know what dose might cause cancer in adults or children. (Safrole occurs naturally in many spices, like nutmeg, but in amounts tiny enough to be considered harmless.) Although lab experiments show that safrole has antifungal and antibacterial properties, no clinical research has provided evidence for its -- or sassafras’ -- supposed health benefits.

Dietary supplement makers are not required by the U.S. government to demonstrate that their products are safe or effective. Ask your healthcare provider for advice on selecting a brand.

-- Elena Conis