Sarsaparilla is a thorny, climbing vine from the genus Smilax, native to Central and South America, Mexico, Jamaica, the Caribbean, and parts of the southern United States. Its root has been used for centuries as both a flavoring ingredient in beverages and a traditional herbal remedy, most famously as a “blood purifier” and treatment for skin conditions. Today, the word shows up on old-fashioned soda labels, in herbal supplement aisles, and across traditional medicine systems worldwide.
The Plant Behind the Name
Sarsaparilla refers not to a single species but to a group of tropical and subtropical vines in the Smilax genus. The most commonly referenced medicinal species is Smilax ornata (sometimes called Smilax officinalis), but dozens of Smilax species grow across the Americas, parts of Asia, and even the southeastern United States. Smilax pumila, for example, is a dwarf variety native to a stretch from South Carolina down through Florida and west to Texas.
The plants share a few features: woody, prickly stems that climb over other vegetation, heart-shaped or lance-shaped leaves, and a dense, fibrous root system. It’s the root that people harvest. When dried and cut, sarsaparilla root has a mildly earthy, slightly bitter flavor with notes that overlap with licorice.
Centuries of Medicinal Use
Indigenous peoples throughout Central and South America used sarsaparilla root long before European contact, primarily for skin problems and as a general tonic. When Spanish colonizers brought the root back to Europe in the 19th century, it quickly gained a reputation as a treatment for syphilis, gout, rheumatism, and scrofula (a form of tuberculosis affecting the lymph nodes). King’s American Dispensatory, a major pharmaceutical reference published in 1898, listed sarsaparilla for syphilis and other venereal diseases.
It was also widely prescribed for chronic skin conditions like psoriasis, boils, and eczema. Practitioners described it as a “blood purifier,” a concept rooted in the older humoral model of medicine, meaning they believed it could cleanse toxins from the body. While that framework is outdated, some of the biological effects researchers now study in the root may explain why traditional healers found it useful.
What’s Inside the Root
The chemistry of sarsaparilla root centers on steroidal saponins, a class of plant compounds responsible for most of its proposed biological activity. Researchers have isolated at least five distinct steroidal saponins from Smilax roots, including compounds called sarsaparilloside, parillin, and several newly identified variants. The root also contains a compound called sarsasapogenin, which appears to be the active form that the body produces after gut bacteria break down the saponins you ingest.
Beyond saponins, sarsaparilla root contains polysaccharides (complex sugars) and various flavonoids. These aren’t just filler. The polysaccharides from at least one Smilax species have shown strong anti-inflammatory effects in laboratory research, reducing key inflammatory signals in the body.
Anti-Inflammatory and Immune Effects
The most promising area of modern research on sarsaparilla involves inflammation. In lab and animal studies, sarsasapogenin and related compounds from the root reduce the production of several major inflammatory molecules: TNF-alpha, interleukin-6, and interleukin-1 beta. These are the same signals your immune system ramps up during infections, autoimmune flares, and chronic inflammatory conditions.
The mechanism appears to work at a fundamental level. Sarsasapogenin interferes with a core inflammatory pathway that gets triggered when immune cells detect bacterial toxins. In animal models of colitis (intestinal inflammation), polysaccharides from Smilax glabra significantly lowered inflammatory markers in both blood and colon tissue. They also promoted the growth of beneficial gut bacteria, particularly strains linked to lower inflammation. One of the more interesting findings is that sarsasapogenin reduced how strongly bacterial toxins could bind to immune cell receptors, essentially dampening the alarm signal before it fully activates the immune response.
Lab studies have also found that one saponin from the root showed notable activity against a colon cancer cell line, though this is far from clinical evidence of any anticancer effect in humans.
Does It Actually Help Skin Conditions?
Despite sarsaparilla’s long folk history for psoriasis and eczema, direct clinical evidence in humans is essentially nonexistent. No controlled trials have tested sarsaparilla on its own for any skin condition. A few tissue-culture and animal studies suggest that certain Smilax species can reduce symptoms of psoriasis and rheumatoid arthritis, but these are early-stage findings that haven’t been replicated in people.
The anti-inflammatory activity described in lab research offers a plausible explanation for why traditional healers observed improvements in skin conditions. Psoriasis and eczema both involve overactive inflammatory pathways, and compounds that suppress those pathways could theoretically help. But “plausible” is not the same as “proven,” and no health authority currently recommends sarsaparilla as a treatment for skin disease.
Sarsaparilla as a Beverage
If you’ve seen sarsaparilla on a drink menu or in a glass bottle at a specialty shop, you’re looking at the other half of the plant’s story. Sarsaparilla soda and root beer are related but distinct drinks. Traditional root beer was brewed from sassafras root, which has an anise-like, earthy flavor. Sarsaparilla soda was brewed from sarsaparilla root, which tastes more bitter and intense. Both were popular in 19th-century America.
The two drinks diverged further in 1960 when the FDA banned sassafras root bark as a food additive because of a potentially harmful compound it contains. Modern root beer is now flavored with wintergreen, anise, and other substitutes. Most modern sarsaparilla sodas also use artificial flavoring, though a few brewers (Bundaberg being a well-known example) still use real sarsaparilla root alongside licorice root, ginger root, vanilla bean, and molasses. The flavor profile is darker and more herbaceous than standard root beer.
Supplements and Typical Doses
Sarsaparilla root is sold as dried root, capsules, powders, and liquid tinctures. A typical dose cited in herbal references is two to four grams of dried root, taken three times per day. Tinctures vary widely in concentration, so dosing depends on the product.
There are no standardized dosing guidelines from any major medical authority, and clinical studies in humans are too scarce to establish an evidence-based dose. If you’re using a supplement, following the manufacturer’s label instructions is the standard recommendation in herbal practice.
Safety and Side Effects
Sarsaparilla has a long history of being eaten raw, cooked in soups, and used in traditional Chinese medicine, which suggests a reasonable safety profile at typical food-level amounts. No formal contraindications have been identified. The most commonly reported side effects are mild: stomach irritation and increased urination.
There are a few interactions worth knowing about. Animal research suggests sarsaparilla may increase absorption of digitalis-based heart medications and speed up elimination of certain sedatives. It could also have an additive effect with diuretics or the gout medication allopurinol. One animal study found that a Smilax species reduced blood levels of methotrexate, a drug used for autoimmune conditions and cancer, which could make the medication less effective.
Sarsaparilla should be avoided during pregnancy and breastfeeding. Extracts from at least one Smilax species have shown both estrogenic and antiestrogenic activity, and there’s no safety data for these populations. Occupational exposure to sarsaparilla root dust has also been linked to asthma in at least one reported case, a concern for people who handle large quantities of the raw material rather than for typical consumers.