Sarsaparilla

Sarsaparilla has been used as a blood cleanser and for abscesses, ulcers, syphilis, shingles, wound washes, asthma, rheumatism, digestive weakness, gout, gonorrhea, 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, sarsaparilla was considered a tonic, blood purifier, diuretic, and diaphoretic. After its introduction in the 1500s, Smilax became a popular treatment for syphilis, which had reached epidemic proportions; the standard alternative of the day was mercury, which frequently caused insanity, blindness, loss of teeth, muscle atrophy, and death ^{30Reference 30Taylor · 2005The Healing Power of Rainforest Herbs: A Guide to Understanding and Using Herbal Medicinals}.

Smilax spp. was also marketed as a steroidal supplement for bodybuilders in the 1980s, though no evidence supports an anabolic effect (see Safety). It is mentioned in Monardes (1577), Gerard (1597), Hill (1751), Parke-Davis (1890) and the works of the eclectics, reflecting its long acceptance in Western materia medica.

Sarsaparilla was used to make root beer, but — contrary to popular belief — largely for its foaming rather than its flavour: the root is nearly tasteless and its high saponin content acts like a detergent, causing water to foam ^{30Reference 30Taylor · 2005The Healing Power of Rainforest Herbs: A Guide to Understanding and Using Herbal Medicinals}.

Smilax spp. is commonly used in soups and herbal teas in China, and in Sri Lanka and Thailand for cancer and skin conditions ^{29Reference 29Wu H et al. · 2022ReviewSmilax glabra Roxb.: A Review of Its Traditional Usages, Phytochemical Constituents, Pharmacological Properties, and Clinical Applications — reviewView study →}. Referred to as “tu fu ling,” it is considered sweet, bland and neutral in nature, entering the liver and stomach meridians. It is used to clear damp-heat and “poison,” benefit the skin, and open the channels.

In South America, Smilax has been used for centuries for sexual impotence, rheumatism, skin ailments, and as a general tonic for weakness. In Peru the root was used for headaches, joint pain and infections such as influenza. Throughout the Amazon, shamans used it for leprosy (contracted from armadillos, a food item) and other skin disorders including psoriasis ^{30Reference 30Taylor · 2005The Healing Power of Rainforest Herbs: A Guide to Understanding and Using Herbal Medicinals}.

This is the most thoroughly reproduced pharmacology in the genus. In potassium-oxonate-induced hyperuricaemic mice, Smilax china extract lowered serum uric acid by inhibiting xanthine oxidase and enhancing 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 edema and renal injury in a combined potassium-oxonate/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 →}, and 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 augmented 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 →}, and 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 are from Rebixiao granules — a multi-herb formula containing Smilax, not the herb alone — which reduced blood uric acid in recurrent acute gout ^{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 rodent; the human signal is confounded by a multi-ingredient formula, and the effective fraction is saponin/flavonoid-rich extract, not the traditional tincture.

An aqueous S. china extract (1000 mg/kg) matched acetylsalicylic acid (200 mg/kg) for anti-inflammatory effect in rat edema and inhibited both COX-2 activity and expression, the enzyme driving pro-inflammatory PGE₂ ^{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 edema and cotton-pellet granuloma in rodents and blunted LPS-driven cytokine release in macrophages via 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 cut 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 →}, and among six isolated S. glabra flavonoids — astilbin, neoastilbin, isoastilbin, neoisoastilbin, engeletin and epicatechin — several reduced IL-1β, IL-6 and NO production ^{11Reference 11Zhao X et al. · 2020In vitroAntioxidant and Anti-Inflammatory Activities of Six Flavonoids from Smilax glabra Roxb. — in vitroView study →}.

Gap: convincing across animals and cells but entirely preclinical; the aspirin-equivalence figure is a single high-dose rat comparison, not a clinical benchmark.

Astilbin (50 mg/kg orally for 7 days) reduced acetaminophen-induced acute liver injury in mice, working partly through the gut microbiota because of its low oral bioavailability and intestinal accumulation ^{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 →}. Older S. china work found its resveratrol/oxyresveratrol content reduced nicotine-driven oxidative damage and induced CYP2A6, speeding nicotine clearance — though that was a cell/enzyme model, not a live liver ^{14Reference 14Kim KM et al. · 2014In vitroSmilax china root extract detoxifies nicotine by reducing reactive oxygen species and inducing CYP2A6 — in vitroView study →}. The same antioxidant/detoxifying theme extends to the kidney, where S. glabra eased cisplatin-induced acute kidney injury in mice via 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 “detox” claim 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 six purified S. glabra flavonoids confirmed astilbin — the herb’s marker compound — 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, well characterised from tea, are also present and plausibly add to the net antioxidant capacity ^{10Reference 10Lu CL et al. · 2014In vitroAntioxidant and Anti-Inflammatory Activities of Phenolic-Enriched Extracts of Smilax glabra — in vitroView study →}.

Gap: consistent but almost entirely chemical/cell-assay data; free-radical scavenging in a cuvette does not establish antioxidant benefit in the body, and no human biomarker study exists.

A S. aristolochiifolia root extract standardised on N-trans-feruloyl-tyramine curbed metabolic-syndrome markers in mice: ~30% less weight gain, ~60% lower triglycerides, ~40% improved insulin resistance and roughly a third lower blood pressure ^{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 →}, and an ethyl-acetate fraction with α-glucosidase/α-amylase inhibition 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 gut-microbiota balance ^{19Reference 19Wang T et al. · 2022AnimalAstilbin from Smilax glabra Roxb. alleviates high-fat diet-induced metabolic dysfunction — animal modelView study →}.

Gap: promising but heterogeneous — different species, different standardised fractions — and no human metabolic endpoints; the headline percentage reductions come from one mouse study.

A phytochemical survey of S. glabra rhizome isolated 63 phenolic compounds, including six new ones, and found activity against gram-positive bacteria — methicillin-resistant Staphylococcus aureus, S. aureus, several Streptococcus species and Enterococcus faecalis — as well as the yeast Candida albicans, through compound-specific mechanisms ^{20Reference 20Xu S et al. · 2013In vitroChemical constituents from the rhizomes of Smilax glabra and their antimicrobial activity — in vitroView study →}.

Gap: entirely in-vitro isolated-compound data; no whole-extract, animal-infection or clinical confirmation, and minimum inhibitory concentrations were not tied to achievable tissue levels.

Traditional use for psoriasis has some modern preclinical backing. 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 plus an imiquimod-induced mouse model showed S. glabra dampens 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 →}, and an ethyl-acetate fraction of S. china reduced imiquimod psoriasis severity by inhibiting IL-17-driven T-cell responses, benchmarked 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; the flavonoid, not the whole tincture, carries the effect, and there is no controlled human trial despite centuries of topical/internal traditional use.

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 →}; and 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 — no animal tumour models, no pharmacokinetics showing these concentrations are reachable, and no human data. Traditional “cancer” use should not be read as validated activity.

In the same study that established anti-inflammatory activity, an aqueous S. china extract (1000 mg/kg) significantly reduced acetic-acid-induced abdominal writhing and prolonged hot-plate latency in mice, an effect attributed to inhibition of prostaglandin-mediated pain signalling ^{8Reference 8Shu XS et al. · 2006AnimalAnti-inflammatory and anti-nociceptive activities of Smilax china L. aqueous extract — animal modelView study →}.

Gap: rests on essentially one rodent study and is mechanistically inseparable from the anti-inflammatory (COX/PGE₂) action rather than a distinct analgesic pathway.

Sarsaparilla has a long food and folk-medicine history and no formal human toxicology, so its safety profile is inferred rather than tested. The most important correction is that it does not contain testosterone or anabolic steroids: its plant sterols and steroidal saponins can be chemically converted to steroid hormones only in a laboratory, not in the body, and the anabolic marketing is unsupported ^{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 saponin content acts as a surfactant (the source of its historical root-beer foaming), which can be locally irritating to the gut and may cause nausea at high doses; saponins can also transiently reduce absorption of some co-administered drugs and nutrients. Interactions have not been formally studied — a theoretical concern exists around the herb altering absorption of other medicines (a use it was traditionally valued for) and around S. china’s in-vitro induction of the nicotine-metabolising enzyme CYP2A6 ^{14Reference 14Kim KM et al. · 2014In vitroSmilax china root extract detoxifies nicotine by reducing reactive oxygen species and inducing CYP2A6 — in vitroView study →}, neither of which has been confirmed clinically. Finally, because commercial “sarsaparilla” spans several botanically distinct Smilax species with different chemistry and potency, product composition is inherently variable.