Sarsaparilla

Sarsaparilla has been used as a blood cleanser and for abscesses, ulcers, syphilis, shingles, wound washes, asthma, rheumatism, digestive weakness, gout, gonorrhoea, arthritis, fever, cough, scrofula, hypertension, psoriasis, skin diseases and cancer ^{30Reference 30Taylor · 2005The Healing Power of Rainforest Herbs: A Guide to Understanding and Using Herbal Medicinals}.

In Europe it was considered a tonic, blood purifier, diuretic and diaphoretic. After its introduction in the 1500s it became a popular treatment for syphilis, which had reached epidemic proportions and was otherwise treated with mercury ^{30Reference 30Taylor · 2005The Healing Power of Rainforest Herbs: A Guide to Understanding and Using Herbal Medicinals}. It is mentioned in Monardes (1577), Gerard (1597), Hill (1751), Parke-Davis (1890) and the works of the Eclectics.

It was traditionally said to work better alongside sassafras and burdock, and to “carry” or enhance the other herbs in a formula ^{30Reference 30Taylor · 2005The Healing Power of Rainforest Herbs: A Guide to Understanding and Using Herbal Medicinals}.

The root is nearly tasteless. Its use in root beer was largely for foam, since its saponins make water froth ^{30Reference 30Taylor · 2005The Healing Power of Rainforest Herbs: A Guide to Understanding and Using Herbal Medicinals}.

Smilax glabra rhizome is tu fu ling. The Song-dynasty Ben Cao Tu Jing first recorded it as sweet, neutral in nature and non-toxic, and the Ming-dynasty Ben Cao Gang Mu recorded its use for syphilitic skin lesions ^{29Reference 29Wu H et al. · 2022ReviewSmilax glabra Roxb.: A Review of Its Traditional Usages, Phytochemical Constituents, Pharmacological Properties, and Clinical Applications — reviewView study →}.

Later texts describe it as removing rheumatism, promoting urination, stopping diarrhoea and treating the muscles and bones. The 2020 Chinese Pharmacopoeia lists it for syphilis, turbid urine, carbuncles, scrofula and scabies ^{29Reference 29Wu H et al. · 2022ReviewSmilax glabra Roxb.: A Review of Its Traditional Usages, Phytochemical Constituents, Pharmacological Properties, and Clinical Applications — reviewView study →}.

It is also eaten in soups and teas to clear heat and dampness ^{29Reference 29Wu H et al. · 2022ReviewSmilax glabra Roxb.: A Review of Its Traditional Usages, Phytochemical Constituents, Pharmacological Properties, and Clinical Applications — reviewView study →}.

In Thailand, traditional practitioners use S. glabra for cancer and for infectious diseases ^{29Reference 29Wu H et al. · 2022ReviewSmilax glabra Roxb.: A Review of Its Traditional Usages, Phytochemical Constituents, Pharmacological Properties, and Clinical Applications — reviewView study →}.

In South America, Smilax has been used for centuries for sexual impotence, rheumatism and skin ailments, and as a tonic for weakness and convalescence. In Peru the root was taken for headaches, joint pain and fevers such as influenza ^{30Reference 30Taylor · 2005The Healing Power of Rainforest Herbs: A Guide to Understanding and Using Herbal Medicinals}.

Throughout the Amazon, healers used it for leprosy and other skin disorders, including psoriasis. In formulas it was valued as a “carrier” that helps deliver the other herbs it is combined with ^{30Reference 30Taylor · 2005The Healing Power of Rainforest Herbs: A Guide to Understanding and Using Herbal Medicinals}.

In potassium-oxonate-induced hyperuricemic mice, Smilax china extract lowered serum uric acid by inhibiting xanthine oxidase and increasing renal urate excretion, through several distinct constituents ^{1Reference 1Chen L et al. · 2011AnimalAnti-hyperuricemic and nephroprotective effects of Smilax china L. — animal modelView study →}.

S. glabra (tu fu ling) water extract repeated the effect, and also reduced paw swelling and kidney injury in a combined potassium-oxonate and monosodium-urate gout model ^{2Reference 2Liang G et al. · 2019AnimalProtective effects of Rhizoma smilacis glabrae extracts on potassium oxonate- and monosodium urate-induced hyperuricemia and gout in mice — animal modelView study →}. The four astilbin stereoisomers were identified as the active uric-acid-lowering fraction, acting on renal urate transporters ^{3Reference 3Huang L et al. · 2019AnimalThe anti-hyperuricemic effect of four astilbin stereoisomers in Smilax glabra on hyperuricemic mice — animal modelView study →}.

A related species, S. riparia, and its saponin pallidifloside D enhanced allopurinol’s uric-acid lowering in mice ^{4,5Reference 4Wu XH et al. · 2015AnimalAnti-hyperuricemia effects of allopurinol are improved by Smilax riparia — animal modelView study →Reference 5Hou PY et al. · 2015AnimalPallidifloside D from Smilax riparia enhanced allopurinol effects in hyperuricemia mice — animal modelView study →}. Total saponins of S. nipponica eased gouty-arthritis inflammation in rats ^{6Reference 6Yuan C et al. · 2025AnimalPotential anti-gout properties of total saponins from Smilax nipponica, determined by UPLC-Q/TOF-MS — animal modelView study →}.

The only human data come from Rebixiao granules, a multi-herb formula containing Smilax. In 90 patients with recurrent acute gout, it lowered blood uric acid compared with diclofenac ^{7Reference 7Ji W et al. · 2005Clinical trialEffects of Rebixiao granules on blood uric acid in patients with repeatedly attacking acute gouty arthritis — clinical (multi-herb formula)View study →}.

Gap: every single-herb result is in rodents, the human result is from a multi-ingredient formula, and the effective fraction is a saponin- or flavonoid-rich extract rather than the traditional tincture.

An aqueous S. china extract (1,000 mg/kg) had an anti-inflammatory effect on egg-albumin-induced oedema in rats similar to acetylsalicylic acid (200 mg/kg), and inhibited both COX-2 activity and expression in macrophages ^{8Reference 8Shu XS et al. · 2006AnimalAnti-inflammatory and anti-nociceptive activities of Smilax china L. aqueous extract — animal modelView study →}.

A flavonoid-enriched S. china root extract suppressed xylene-induced ear swelling and cotton-pellet granuloma in rodents, and reduced LPS-driven cytokine release in macrophages through the TLR-4 pathway ^{9Reference 9Feng H et al. · 2020In vitroThe flavonoid-enriched extract from the root of Smilax china L. inhibits inflammatory responses via the TLR-4-mediated signaling pathway — animal model / in vitroView study →}.

Phenolic-enriched S. glabra extract reduced nitric oxide, TNF-α and other mediators in LPS-stimulated cells ^{10Reference 10Lu CL et al. · 2014In vitroAntioxidant and Anti-Inflammatory Activities of Phenolic-Enriched Extracts of Smilax glabra — in vitroView study →}. Among six isolated S. glabra flavonoids — astilbin, neoastilbin, isoastilbin, neoisoastilbin, engeletin and epicatechin — several reduced IL-1β, IL-6 and nitric oxide production ^{11Reference 11Zhao X et al. · 2020In vitroAntioxidant and Anti-Inflammatory Activities of Six Flavonoids from Smilax glabra Roxb. — in vitroView study →}.

The findings are consistent across animals and cells but entirely preclinical. The aspirin comparison is a single high-dose rat study.

Astilbin (50 mg/kg orally for 7 days) reduced paracetamol-induced acute liver injury in mice. It worked partly through the gut microbiota, since it is poorly absorbed and accumulates in the intestine ^{12Reference 12Yang Q et al. · 2025AnimalOral administration of astilbin mitigates acetaminophen-induced acute liver injury in mice by modulating the gut microbiota — animal modelView study →}.

A flavonoid-rich S. glabra fraction protected rat liver against carbon-tetrachloride toxicity ^{13Reference 13Xia D et al. · 2013AnimalProtective effects of the flavonoid-rich fraction from rhizomes of Smilax glabra Roxb. on carbon tetrachloride-induced hepatotoxicity — animal modelView study →}.

In a cell and enzyme model, the resveratrol and oxyresveratrol in S. china reduced nicotine-driven oxidative damage and induced CYP2A6, the enzyme that clears nicotine ^{14Reference 14Kim KM et al. · 2014In vitroSmilax china root extract detoxifies nicotine by reducing reactive oxygen species and inducing CYP2A6 — in vitroView study →}.

In the kidney, S. glabra eased cisplatin-induced acute kidney injury in mice through the Nrf2/HO-1 pathway ^{15Reference 15Zhao L et al. · 2025AnimalSmilax glabra Roxb. alleviates cisplatin-induced acute kidney injury in mice by activating the Nrf2/HO-1 signalling pathway — animal modelView study →}.

Gap: the strongest data are for isolated astilbin, not whole root. No human liver-function studies exist, and the CYP2A6 finding is in vitro.

Phenolic-enriched S. glabra extract showed strong DPPH and ABTS radical scavenging and ferric-reducing power, matching or exceeding ascorbic acid for ABTS in vitro ^{10Reference 10Lu CL et al. · 2014In vitroAntioxidant and Anti-Inflammatory Activities of Phenolic-Enriched Extracts of Smilax glabra — in vitroView study →}.

Screening of six purified S. glabra flavonoids identified astilbin and its stereoisomers as the main antioxidant contributors ^{11Reference 11Zhao X et al. · 2020In vitroAntioxidant and Anti-Inflammatory Activities of Six Flavonoids from Smilax glabra Roxb. — in vitroView study →}. Catechins and epicatechin are also present ^{10Reference 10Lu CL et al. · 2014In vitroAntioxidant and Anti-Inflammatory Activities of Phenolic-Enriched Extracts of Smilax glabra — in vitroView study →}.

The data are almost entirely chemical and cell assays. They do not establish an antioxidant effect in the body, and no human biomarker study exists.

A S. aristolochiifolia root extract standardised on N-trans-feruloyl-tyramine reduced metabolic-syndrome markers in mice. The extract and its fractions cut weight gain by about 30%, the fraction rich in the marker lowered triglycerides by 60%, insulin resistance fell by about 40%, and systolic and diastolic pressure fell by 31% and 37% ^{16Reference 16Amaro CA et al. · 2014AnimalHypoglycemic and hypotensive activity of a root extract of Smilax aristolochiifolia, standardized on N-trans-feruloyl-tyramine — animal modelView study →}.

Rhizome extracts of S. glabra lowered blood glucose in normal and diabetic mice ^{17Reference 17Fukunaga T et al. · 1997AnimalHypoglycemic effect of the rhizomes of Smilax glabra in normal and diabetic mice — animal modelView study →}. An ethyl-acetate fraction that inhibits α-glucosidase and α-amylase reduced glucose and insulin resistance in a type-2 model ^{18Reference 18Nguyen PTM et al. · 2020AnimalHypoglycemic activity of the ethyl acetate extract from Smilax glabra Roxb in mice — animal modelView study →}.

Astilbin itself reduced body weight, insulin resistance and inflammation in high-fat-diet mice while improving the balance of the gut microbiota ^{19Reference 19Wang T et al. · 2022AnimalAstilbin from Smilax glabra Roxb. alleviates high-fat diet-induced metabolic dysfunction — animal modelView study →}.

Gap: the studies use different species and different standardised fractions, there are no human metabolic endpoints, and the headline percentages come from one mouse study.

A phytochemical survey of S. glabra rhizome isolated 63 phenolic compounds, six of them new. Thirty were tested against three Gram-negative bacteria, three Gram-positive bacteria and one fungus; 18 were active, with MICs of 0.08–3.1 mM. The strongest named hits were against Candida albicans and Staphylococcus aureus ^{20Reference 20Xu S et al. · 2013In vitroChemical constituents from the rhizomes of Smilax glabra and their antimicrobial activity — in vitroView study →}.

This is in-vitro isolated-compound data, with no whole-extract, animal-infection or clinical confirmation.

Quercetin isolated from S. china rhizome improved epidermal thickness and orthokeratosis in the mouse-tail psoriasis model ^{21Reference 21Vijayalakshmi A et al. · 2012AnimalScreening of flavonoid “quercetin” from the rhizome of Smilax china Linn. for anti-psoriatic activity — animal modelView study →}.

Network pharmacology combined with an imiquimod-induced mouse model showed that S. glabra reduces psoriatic skin inflammation by regulating T-cell differentiation ^{22Reference 22Guo Y et al. · 2024AnimalIntegrated network pharmacological analysis revealed that Smilax glabra Roxb. alleviates IMQ-induced psoriatic skin inflammation through regulating T cell immune response — animal modelView study →}. An ethyl-acetate fraction of S. china reduced imiquimod psoriasis severity by inhibiting IL-17-driven T-cell responses, compared against methotrexate ^{23Reference 23Wang Y et al. · 2026AnimalSmilacis Chinae Rhizoma ethyl acetate fraction alleviates IMQ-induced psoriasis by inhibiting IL-17-driven T-cell immune responses — animal modelView study →}.

Gap: all rodent or mechanistic work on isolated flavonoids or fractions, with no controlled human trial.

Antiproliferative activity is documented only in cell lines. Steroidal saponins from a commercial sarsaparilla (S. ornata), including a new furostanol saponin, were antiproliferative across six tumour lines, most active against HT29 colon cancer ^{24Reference 24Challinor VL et al. · 2012In vitroSteroidal saponins from the roots of Smilax sp.: structure and bioactivity — in vitroView study →}.

Polyphenols from S. china were cytotoxic to breast tumour cells and acted partly as antiestrogenic phytoestrogens ^{25Reference 25Wu LS et al. · 2010In vitroCytotoxic polyphenols against breast tumor cell in Smilax china L. — in vitroView study →}.

S. china rhizome extract inhibited NF-κB and induced apoptosis in ovarian cancer cells ^{26Reference 26Hu LL et al. · 2015In vitroSmilax china L. rhizome extract inhibits nuclear factor-κB and induces apoptosis in ovarian cancer cells — in vitroView study →}.

A methanol extract triggered ERK-dependent, death-receptor-5-mediated apoptosis in oral carcinoma cells ^{27Reference 27Yu HJ et al. · 2014In vitroExtracellular signal-regulated kinase inhibition is required for methanol extract of Smilax china L. induced apoptosis through death receptor 5 in human oral mucoepidermoid carcinoma cells — in vitroView study →}.

Gap: in-vitro cytotoxicity only, with no animal tumour models, no evidence that these concentrations are reachable in the body, and no human data.

In the same study that measured anti-inflammatory activity, an aqueous S. china extract (1,000 mg/kg) reduced acetic-acid-induced writhing and prolonged hot-plate latency in mice, an effect attributed to reduced prostaglandin production ^{8Reference 8Shu XS et al. · 2006AnimalAnti-inflammatory and anti-nociceptive activities of Smilax china L. aqueous extract — animal modelView study →}. This rests on one rodent study and follows from the same COX/PGE₂ action as the anti-inflammatory effect.

Not a steroid. Sarsaparilla was marketed to bodybuilders in the 1980s as a steroidal supplement ^{30Reference 30Taylor · 2005The Healing Power of Rainforest Herbs: A Guide to Understanding and Using Herbal Medicinals}. Its plant sterols and steroidal saponins can be converted into steroid hormones in a laboratory, but not in the body, and there is no evidence of an anabolic effect ^{24,30Reference 24Challinor VL et al. · 2012In vitroSteroidal saponins from the roots of Smilax sp.: structure and bioactivity — in vitroView study →Reference 30Taylor · 2005The Healing Power of Rainforest Herbs: A Guide to Understanding and Using Herbal Medicinals}.

The gut. The saponins act as surfactants, which is what made the root foam in root beer ^{30Reference 30Taylor · 2005The Healing Power of Rainforest Herbs: A Guide to Understanding and Using Herbal Medicinals}. At high doses they can irritate the gut and cause nausea.

Other medicines. Saponins can reduce the absorption of some drugs and nutrients taken at the same time.

Drug metabolism. In laboratory tests, astilbin and its isomers neoastilbin and isoastilbin inhibited the drug-metabolising enzymes CYP3A4 and CYP2D6 ^{36Reference 36Shi Y et al. · 2021In vitroInhibitory effects of astilbin, neoastilbin and isoastilbin on human cytochrome CYP3A4 and 2D6 activities — in vitroView study →}. S. china root extract induced the nicotine-clearing enzyme CYP2A6 in liver cells ^{14Reference 14Kim KM et al. · 2014In vitroSmilax china root extract detoxifies nicotine by reducing reactive oxygen species and inducing CYP2A6 — in vitroView study →}. None of these effects has been studied in animals or people.

Product variation. Commercial sarsaparilla spans several Smilax species with different chemistry and potency, so products vary.