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Sassafras: Benefits, Dangers and Side Effects

Known by some as America’s only native spice, sassafras is an ancient plant with a long history of traditional use. Yet sassafras has also been condemned as a potential toxin. So which is correct? In this article, we’re going to take a deep dive into the controversy and explore the potential benefits, dangers, and side effects of sassafras.

A Brief History of Sassafras

The genus Sassafras includes four species of deciduous tree, one of which is now extinct. Native to both North America and Asia, the most well-known member of the laurel family (Lauraceae) is Sassafras albidum, which is found in eastern North America.

If you spend any time in the forests of the southern and eastern United States, chances are you’ve seen this distinctive tree. Unlike most deciduous trees, whose leaves all tend to look alike, the sassafras tree sports three distinct leaf shapes—trilobed, mitten-shaped, and oval—on the same tree.

Sassafras has been an integral part of Native American life for centuries. It was traditionally used to treat wounds and fevers, start fires, flavor food, and cure meat. The Creole dish gumbo is also said to have originated with the Choctaw practice of using filé powder—a spice made from the ground leaves of the sassafras tree—in cooking.

Sassafras was so widely used that in the 1600s, after the arrival of Europeans, it became America's largest export after tobacco.

The Sassafras Controversy

Sassafras has been used to make both tea and candy, but it’s probably best known for its use as a flavoring agent in root beer.

While sassafras-infused root beer was widely available beginning in the 19th century, it was banned in the 1960s, when large doses of safrole—the active component of sassafras oil, which is also found in lesser amounts in nutmeg, cinnamon, and black pepper—were found in rodent studies to cause liver damage and cancer. Moreover, safrole is the chemical precursor to MDMA, or ecstasy.

But root beer wasn’t the only sassafras product that found itself on the wrong side of the U.S. Food and Drug Administration (FDA). The interstate shipment of root bark for the making of sassafras tea was also banned in 1977. 

However, the outright ban on sassafras was lifted after the Dietary Supplement Health and Education Act was passed in 1994, and now both sassafras essential oil and root bark can be purchased legally—though you still won’t find sassafras in commercially available root beer unless it’s had its safrole removed.

Potential Health Benefits of Sassafras

With hundreds, if not thousands, of years of traditional use, many health practitioners continue to fight against the stigma that’s been attached to sassafras since it was first banned. 

And, in their defense, it’s important to note that safrole is found in just the bark and oil, and the studies used to justify the initial ban involved giving massive amounts of safrole to rats. By contrast, the only report of adverse effects in humans involves a man who experienced excessive sweating after drinking too much sassafras tea. For an even more interesting and entertaining take on the potentially bad science used to justify the ban on sassafras, check out this article from Nature’s Poisons.

Another factor some health practitioners point to in their defense of sassafras is the fact that researchers are continuing to look into the possible medicinal uses of sassafras. 

So, with that in mind, let’s now take a look at some of the potential health benefits of sassafras.

Sassafras Warnings and Potential Side EffectsCancer

In contrast to the rodent studies of the 1960s, which found a link between safrole and cancer, multiple recent studies have found that safrole may actually be effective against a variety of cancers.

For example, in a study published in the journal Experimental Lung Research, researchers discovered that safrole oxide may have the ability to kill lung cancer cells.

In another study published in the Journal of Dental Research, safrole was shown to reduce the viability of oral cancer cells and induce cell death.

Likewise, a study published in the International Journal of Clinical and Experimental Pathology found that safrole displays potent activity against liver cancer cells and can suppress both growth and proliferation.

And in a study in the journal Molecules, researchers found that catechols synthesized from safrole exhibited toxicity toward two breast cancer cell lines (MCF-7 and MDA-MB-231) but did not harm healthy skin cells.

In another study published in the Journal of Receptors and Signal Transduction, researchers found that safrole decreased the viability of prostate cancer cells.

Finally, a study in the journal Pharmacological Research found that safrole has the ability to cause osteosarcoma cell death.


A rodent study published in the journal Drug Research found that rats who received 100 and 200 milligrams per kilogram of safrole—an amount that far exceeds the toxicity level set by earlier studies—experienced significant improvement in symptoms of diabetes.


In a study published in the journal Natural Product Communications, researchers found that sassafras bark extract exhibits “excellent” activity against the parasites that cause leishmaniasis—a tropical disease spread by sandflies.


Sassafras contains several compounds that act as antioxidants—compounds known to fight free radicals and oxidative damage as well as chronic inflammation, which is associated with a higher risk of chronic disease, including heart disease, diabetes, cancer, and Alzheimer’s disease.

A study in the journal Natural Product Research found that sassafras contains a number of phytochemicals that display moderate activity against inducible nitric oxide synthase (iNOS)—an enzyme required for the formation of free radicals.

Alzheimer’s Disease

In a study published in the journal Natural Product Research, researchers discovered several polyphenols in sassafras that act as natural acetylcholinesterase inhibitors—a finding that may have significance for the treatment of conditions such as Alzheimer’s disease, schizophrenia, and glaucoma. 

Acetylcholinesterase inhibitors inhibit the breakdown of the neurotransmitter acetylcholine, which plays a role in muscle contractions, hormone excretion, wakefulness, attentiveness, short-term memory, learning, anger, aggression, sexuality, and thirst.

Sassafras Warnings and Potential Side Effects

As mentioned, there continues to be a fair amount of controversy surrounding the use of sassafras. While consuming moderate amounts of sassafras tea is considered generally safe, sassafras can cause side effects in some people. These include:

  • Excessive sweating
  • Hot flashes
  • Vomiting
  • Hallucinations
  • Skin rashes (when applied topically)

It’s also recommended that sassafras essential oil and root bark be avoided by children and women who are pregnant or breastfeeding. In addition, individuals with heart disease should refrain from using products that contain sassafras bark or oil, as at least one study has found a potential link between safrole and atherosclerotic plaque rupture. Moreover, it’s thought that sassafras may have sedative properties, so it should be avoided by individuals taking sedative medications.

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