Benefits
Traditional support for skin comfort
Sarsaparilla has a long history of traditional use as a so-called blood purifier and skin tonic in herbal traditions of the Americas and Caribbean, often included in formulations aimed at skin. This is a traditional use only. No human clinical trial of sarsaparilla for skin has been published, so there is no evidence it changes anything about skin in people.
Provides plant-source steroidal saponins
Sarsaparilla root supplies steroidal saponins, soap-like plant compounds that have been isolated and studied in laboratory dishes. Despite the name, they are not anabolic steroids and the body does not turn them into testosterone. Test-tube chemistry is not a health benefit, and none of this work was done in people.
Helps support joint and musculoskeletal comfort traditionally
Folk uses in the Caribbean and Latin America have employed Smilax ornata and related sarsaparilla species for rheumatic complaints, and one 2019 study found that root extracts reduced swelling and pain responses in Sprague-Dawley rats. No human trial has tested sarsaparilla for joint pain, so this is traditional use plus a single animal study.
Contributes traditional botanical context to herbal formulas
Sarsaparilla is a common component of classical Western herbal formulas and is still valued culturally as a flavorful root for traditional beverages and bitters. Formulas described as cleansing or detoxifying reflect old folklore about purifying the blood, not any measured effect on the body.
Mechanism of action
Anti-inflammatory and analgesic activity in preclinical models
Methanol and ethyl acetate extracts of Smilax ornata reduced paw swelling and pain responses in rats. This is animal research only. It offers a possible reason the root was used traditionally, but it does not show that sarsaparilla relieves pain, inflammation, or skin problems in people.
Steroidal saponin pharmacology
Steroidal saponins isolated from Smilax roots have shown a range of effects on cells in test tubes, including slowing the growth of cultured tumor cells and breaking open red blood cells. These are observations on isolated cells in a dish, not benefits, and activity against tumor cells in culture is not evidence that sarsaparilla affects cancer in anyone.
Phytosterol contribution
Sarsaparilla root contains small amounts of plant sterols such as sitosterol and stigmasterol. Plant sterols as a class can interfere with cholesterol absorption, but the amounts in a normal serving of sarsaparilla are far below the doses used in that research, and no study has ever measured cholesterol in people taking sarsaparilla.
Clinical trials
In vivo study of methanol, ethyl acetate, and other extracts of Smilax ornata (Jamaican sarsaparilla) in standard rodent models of inflammation and pain (Khan et al., Journal of Ethnopharmacology).
Sprague-Dawley rats in carrageenan paw edema and pain testing.
Methanol extracts at 200 and 400 mg per kg of body weight and the ethyl acetate extract at 400 mg per kg reduced inflammation in rats, and the methanol extract also reduced pain responses. These are animal doses given by body weight and they do not convert into a human capsule dose. Because no human trial has been done, this study cannot tell you whether sarsaparilla helps joint or rheumatic complaints in people.
Phytochemistry and bioactivity study of steroidal saponins isolated from the roots of Smilax species (Challinor et al., Steroids).
Isolated furostanol and spirostanol saponins in tumor cell lines.
Five steroidal saponins, including two newly described ones, were isolated and slowed the growth of tumor cells in culture. This was a chemistry study on purified compounds in laboratory dishes, not a study in animals or people. It says nothing about what happens in the human body and is not evidence of any effect on cancer.