Chinese Skullcap

Pinyin

Huáng Qín

Taste

Bitter ^{41,42Reference 41Yang et al. · 2013Introduction to chinese materia medica (3rd ed.). (Pg 96-98)Reference 42Wu · 2005An illustrated Chinese materia medica}

Energy

Cold ^{41,42Reference 41Yang et al. · 2013Introduction to chinese materia medica (3rd ed.). (Pg 96-98)Reference 42Wu · 2005An illustrated Chinese materia medica}

Channels

Lung, Gallbladder, Stomach, large intestine ^{42Reference 42Wu · 2005An illustrated Chinese materia medica}

Actions

Dispels (clears) heat, expels (drains) damp heat, drains fire, detoxificant, stops bleeding, calms the fetus ^{37,41,42Reference 37Bone · 2003A clinical guide to blending liquid herbs: Herbal formulations for the individual patientReference 41Yang et al. · 2013Introduction to chinese materia medica (3rd ed.). (Pg 96-98)Reference 42Wu · 2005An illustrated Chinese materia medica}.

Indications

The roots are generally the preferred part of the plant in Chinese medicine, used for fevers, cough with thick sputum, pneumonia, nausea, vomiting, hemoptysis, jaundice, viral hepatitis, diarrhoea, dysentery-like diseases, painful urination, hypertension, restless foetus, carbuncles, allergic conditions, hyperlipidemia, vexing heat, internal accumulation of heat toxin, bleeding due to heat exuberance, internal accumulation of damp-heat, and dermatitis ^{37,40,41Reference 37Bone · 2003A clinical guide to blending liquid herbs: Herbal formulations for the individual patientReference 40Barnes et al. · 2007Herbal medicines (3rd ed.)Reference 41Yang et al. · 2013Introduction to chinese materia medica (3rd ed.). (Pg 96-98)}.

Cautions & Safety

Do not use with cold syndromes of deficiency type ^{42Reference 42Wu · 2005An illustrated Chinese materia medica}.

In traditional Chinese medicine, skullcap is considered one of the 50 fundamental herbs, and as such is one of the most commonly used herbs in this medical system ^{38Reference 38Buhner · 2013Herbal antivirals: Natural remedies for emerging resistant and epidemic viral infections}.

In Tibet, S. barbata is the most common species, where it’s juiced (both root and leaves) and used for wounds, fevers, indigestion, and gastric disturbances ^{38Reference 38Buhner · 2013Herbal antivirals: Natural remedies for emerging resistant and epidemic viral infections}.

In North America, the main species used traditionally was S. lateriflora. The Native Americans here used the leaves to treat sore eyes, chills, fever, colds, coughs, heart problems, and as a laxative. The roots were used as an emmenagogue, and abortifacient, antidiarrheal, nervine, treat kidney disorders, cold and flu, and to prevent smallpox ^{38Reference 38Buhner · 2013Herbal antivirals: Natural remedies for emerging resistant and epidemic viral infections}.

The leaves were often used in the form of a tea, or steamed and eaten as a vegetable ^{38Reference 38Buhner · 2013Herbal antivirals: Natural remedies for emerging resistant and epidemic viral infections}.

Priest and priest suggested skullcap as a diffusive, and a stimulating and relaxing vasodilator and trophorestorative. They suggested it useful for treating nervous irritation of the cerebro-spinal nervous system, nervous exhaustion, post-febrile nervous weakness, chorea, hysteria, agitation, epileptiform convulsions, insomnia, and restless sleep. ^{39Reference 39Hoffmann · 2003Medical herbalism: The science and practice of herbal medicine}.

In western botanical practice, skullcaps of all varieties are used mainly as a nervine, but also for conditions such as chorea, convulsions, hysteria, nervous tension, intermittent fever, neuralgia, insomnia, and restlessness. ^{38,40Reference 38Buhner · 2013Herbal antivirals: Natural remedies for emerging resistant and epidemic viral infectionsReference 40Barnes et al. · 2007Herbal medicines (3rd ed.)}.

This is the herb’s best-characterised action and the mechanistic hub for most of the others. The root flavonoids baicalin, baicalein and wogonin suppress the NF-κB pathway and directly inhibit COX-2, lowering TNF-α, IL-6 and IL-1β; in cultured endothelium and in mice all three blunted LPS-driven adhesion-molecule expression and leukocyte migration ^{1Reference 1Lee et al. · 2015In vitroAnti-inflammatory effects of baicalin, baicalein, and wogonin in vitro and in vivo — in vitro and animal studyView study →}. Human evidence exists but is indirect. A randomised, double-blind, placebo-controlled trial (n=374, 12 weeks, 500 mg baicalin daily) in patients with coexisting coronary artery disease and rheumatoid arthritis reported lower blood lipids and hs-CRP ^{2Reference 2Hang et al. · 2018RCTBaicalin reduces blood lipids and inflammation in patients with coronary artery disease and rheumatoid arthritis — randomised, double-blind, placebo-controlled trialView study →}. Two randomised osteoarthritis trials of flavocoxid (500 mg twice daily) — a fixed blend of skullcap baicalin and Acacia catechins — found it noninferior to naproxen over 4–12 weeks ^{3,4Reference 3Levy et al. · 2010RCTEfficacy and safety of flavocoxid compared with naproxen in osteoarthritis of the knee — randomised controlled trialView study →Reference 4Levy et al. · 2009RCTFlavocoxid is as effective as naproxen for osteoarthritis of the knee — randomised, double-blind pilot studyView study →}, and two randomised pilots of the related UP446 blend reported reduced knee pain versus placebo ^{5,6Reference 5Arjmandi et al. · 2014RCTA combination of Scutellaria baicalensis and Acacia catechu extracts for short-term relief of knee osteoarthritis — randomised controlled trialView study →Reference 6Sampalis et al. · 2012RCTA randomised, double-blind, placebo- and active-comparator-controlled pilot study of UP446 — randomised controlled trialView study →}. None of these tested the crude root, and the combination products confound the skullcap contribution; the same flavocoxid product also carries a rare acute-liver-injury signal (see Safety) ^{30,31Reference 30Chalasani et al. · 2012Case reportAcute liver injury due to flavocoxid (Limbrel), a medical food for osteoarthritis — case seriesView study →Reference 31Curtis et al. · 2020ObservationalComparative safety of flavocoxid vs prescription NSAIDs among osteoarthritis patients — observational cohort studyView study →}.

Gap: No trial has tested whole-root skullcap for an inflammatory endpoint; the human data come from a single isolated glycoside or from two-herb combinations.

Baikal skullcap root extract and its dominant flavone baicalein are strong direct radical scavengers and, more importantly, activate the Nrf2/HO-1 axis while suppressing pro-oxidant signalling — the same free-B-ring flavone chemistry that drives the anti-inflammatory effect ^{7Reference 7Chmiel et al. · 2023ReviewPromising role of the Scutellaria baicalensis root hydroxyflavone baicalein as an antioxidant — reviewView study →}. This activity is highly reproducible across chemical assays and cell models and underlies much of the reported organ protection (liver, brain, vasculature) elsewhere on this page. It is also the honest mechanism behind vague “antiaging” marketing claims. Every result, however, is from purified compounds or extracts in vitro and in animals; there is no human antioxidant-biomarker trial of the herb ^{7,8Reference 7Chmiel et al. · 2023ReviewPromising role of the Scutellaria baicalensis root hydroxyflavone baicalein as an antioxidant — reviewView study →Reference 8Fang et al. · 2020Systematic reviewBaicalin and its aglycone: a novel approach for treatment of metabolic disorders — systematic reviewView study →}.

Gap: Entirely preclinical and constituent-driven — no evidence that drinking a decoction raises antioxidant capacity or lowers oxidative-stress markers in people.

The most-studied emerging signal, and the one that pushed a skullcap constituent furthest toward the clinic. In vitro, baicalein and baicalin inhibit the SARS-CoV-2 3C-like protease and RNA-dependent RNA polymerase ^{9,10Reference 9Liu et al. · 2021In vitroScutellaria baicalensis extract and baicalein inhibit replication of SARS-CoV-2 and its 3C-like protease — in vitro studyView study →Reference 10Zandi et al. · 2021In vitroBaicalein and baicalin inhibit SARS-CoV-2 RNA-dependent RNA polymerase — in vitro studyView study →}; skullcap extracts and baicalein block influenza by inhibiting viral neuraminidase ^{11Reference 11Hour et al. · 2013In vitroBaicalein and Scutellaria baicalensis extracts inhibit the neuraminidase activity of pandemic 2009 H1N1 and seasonal influenza A viruses — in vitro studyView study →}; and activity has been shown against respiratory syncytial virus ^{12,13Reference 12Ma et al. · 2002In vitroAntiviral Chinese medicinal herbs against respiratory syncytial virus — in vitro studyView study →Reference 13Qin et al. · 2022In vitroBaicalin induces a potent innate immune response to inhibit respiratory syncytial virus replication — in vitro and mouse studyView study →}, HIV-1 at the viral-entry step ^{14Reference 14Li et al. · 2000In vitroFlavonoid baicalin inhibits HIV-1 infection at the level of viral entry — in vitro studyView study →}, and hepatitis B ^{15Reference 15Fan et al. · 2023In vitroBaicalin inhibits replication of hepatitis B virus by targeting TRIM25 — in vitro studyView study →}. Mechanisms span direct enzyme inhibition, blocked viral entry, and boosted host innate-immune (interferon) responses. Crucially, baicalein has cleared Phase I safety and pharmacokinetic testing as an oral tablet and entered a Phase IIa influenza trial ^{16,17Reference 16Li et al. · 2021RCTSafety, tolerability, and pharmacokinetics of oral baicalein tablets in healthy Chinese subjects — randomised, double-blind, placebo-controlled Phase I multiple-ascending-dose studyView study →Reference 17Dong et al. · 2021RCTSafety, tolerability, pharmacokinetics, and food effect of baicalein tablets in healthy Chinese subjects — randomised, double-blind, placebo-controlled Phase I studyView study →} — the closest any skullcap chemistry has come to a proven antiviral use — but no efficacy result has been published.

Gap: All antiviral efficacy is in cells or, at best, animals; the one human programme tests an isolated compound, not the root, and has not reported whether it actually shortens or prevents infection.

Unusually for this herb, some of the liver work used the actual root rather than a single molecule. A methanol extract of S. baicalensis root reduced liver fibrosis, lipid peroxidation and hydroxyproline in rats with bile-duct ligation or carbon-tetrachloride injury ^{18Reference 18Nan et al. · 2002AnimalScutellaria baicalensis inhibits liver fibrosis induced by bile duct ligation or carbon tetrachloride in rats — animal studyView study →}. Isolated baicalin reproduces this across models of alcohol-associated liver disease, fatty liver and toxin injury, acting through antioxidant, anti-inflammatory and stellate-cell pathways ^{19,20Reference 19Fang et al. · 2022Baicalin confers hepatoprotective effect against alcohol-associated liver disease by upregulating microRNA-205 — animal studyView study →Reference 20Yang et al. · 2021ReviewPharmacological properties of baicalin on liver diseases — narrative reviewView study →}. The mechanism is coherent and the antioxidant/anti-inflammatory basis is well mapped, but the entire body of work is preclinical.

Gap: No human hepatoprotection trial exists, and the herb’s own rare hepatotoxicity signal (see Safety) means “liver protective” cannot be stated for people.

A very large in-vitro and animal literature: baicalein, wogonin and oroxylin A induce apoptosis, arrest the cell cycle and inhibit proliferation across leukaemia, breast, colon, lung and cervical cancer lines, largely by suppressing NF-κB and modulating p53 and the tumour microenvironment ^{21,22Reference 21Banik et al. · 2022Systematic reviewWogonin and its analogs for the prevention and treatment of cancer — systematic reviewView study →Reference 22Zieniuk et al. · 2025Systematic reviewThe therapeutic potential of baicalin and baicalein in breast cancer — systematic reviewView study →}. Two systematic reviews of this preclinical work judge the flavonoids promising but note the near-total absence of clinical data ^{21,22Reference 21Banik et al. · 2022Systematic reviewWogonin and its analogs for the prevention and treatment of cancer — systematic reviewView study →Reference 22Zieniuk et al. · 2025Systematic reviewThe therapeutic potential of baicalin and baicalein in breast cancer — systematic reviewView study →}. Human exposure exists only through multi-herb formulas (e.g. PHY906 alongside chemotherapy) and ex-vivo experiments on patient leukocytes, not through skullcap given as an anticancer treatment.

Gap: No human antitumour efficacy data for the herb or its isolated compounds; the signal is entirely cell-line and rodent.

A long-standing traditional use with plausible mechanism. Skullcap flavonoids stabilise mast cells and cut histamine release, suppress IgE-mediated responses, and drive eosinophil apoptosis: baicalein, wogonin and an ethanol extract reduced airway inflammation in ovalbumin-sensitised mice ^{23Reference 23Bui et al. · 2017Baicalein, wogonin, and Scutellaria baicalensis ethanol extract alleviate ovalbumin-induced allergic airway inflammation — animal studyView study →}, and wogonin induced eosinophil apoptosis while attenuating allergic airway inflammation in a mouse asthma model ^{24Reference 24Lucas et al. · 2015In vitroWogonin induces eosinophil apoptosis and attenuates allergic airway inflammation — in vitro and mouse studyView study →}. This maps onto the herb’s documented traditional use for hay fever and allergic complaints. All of it, however, is cell-based or in mice.

Gap: No human allergy or asthma trial; the effect is well-supported preclinically but unproven in patients.

Baicalein is under active development as an isolated neuroprotective drug, chiefly for Parkinson’s disease. Two systematic reviews and meta-analyses of animal Parkinson’s models found consistent protection of dopaminergic neurons, attributed to antioxidant, anti-inflammatory and anti-aggregation effects ^{25,26Reference 25Wang et al. · 2020Meta-analysisPreclinical evidence and possible mechanisms of baicalein for rats and mice with Parkinson’s disease — systematic review and meta-analysis of animal modelsView study →Reference 26Zhu et al. · 2019Systematic reviewNeuroprotective effects of baicalein in animal models of Parkinson’s disease — systematic review of experimental studiesView study →}, and a preclinical meta-analysis reported antidepressant-like effects of baicalin in rodent models ^{27Reference 27Wang et al. · 2024Meta-analysisThe effects of baicalin in depression: preclinical evidence construction based on meta-analysis of animal studiesView study →}. Baicalein has completed Phase I pharmacokinetic and safety trials in this context ^{28Reference 28Li et al. · 2014RCTSafety, tolerability, and pharmacokinetics of a single ascending dose of baicalein chewable tablets in healthy subjects — randomised Phase I studyView study →}. As with the antiviral programme, the clinical work is on the purified compound, not the herb.

Gap: No human neurological efficacy data; the animal meta-analyses are consistent but the crude herb has never been tested for a cognitive or mood endpoint.

Baicalin improves insulin sensitivity and glucose handling in rodent models, in part by activating hepatic carnitine palmitoyltransferase-1 (CPT1) to increase fatty-acid oxidation and reduce diet-induced obesity and hepatic steatosis ^{29Reference 29Dai et al. · 2018Chemoproteomics reveals baicalin activates hepatic CPT1 to ameliorate diet-induced obesity and hepatic steatosis — animal studyView study →}; a systematic review of preclinical metabolic-disorder studies reaches the same conclusion ^{8Reference 8Fang et al. · 2020Systematic reviewBaicalin and its aglycone: a novel approach for treatment of metabolic disorders — systematic reviewView study →}. Human data are limited to one small controlled study combining skullcap extract with metformin, which is confounded by the drug. Traditional use does not emphasise diabetes, so this rests almost entirely on modern animal pharmacology.

Gap: Essentially no direct human evidence; the mechanism is well mapped in rodents but the herb is not an established antidiabetic.

Chinese skullcap root is generally well tolerated in traditional use, but rare idiosyncratic liver injury has been documented — most clearly in the drug-induced liver injury network’s case series of flavocoxid (Limbrel), a baicalin-containing combination medical food, where four patients developed acute hepatocellular injury that resolved on withdrawal ^{30Reference 30Chalasani et al. · 2012Case reportAcute liver injury due to flavocoxid (Limbrel), a medical food for osteoarthritis — case seriesView study →}. A large claims-based cohort found flavocoxid carried a higher rate of liver injury and hypersensitivity pneumonitis than prescription NSAIDs ^{31Reference 31Curtis et al. · 2020ObservationalComparative safety of flavocoxid vs prescription NSAIDs among osteoarthritis patients — observational cohort studyView study →}. The herb and its flavonoids inhibit and interact with several drug-handling pathways: baicalin inhibits CYP3A activity and displaces plasma protein binding (shown for the CYP3A substrate nifedipine in rats) ^{33Reference 33Cheng et al. · 2014AnimalContribution of baicalin to plasma protein binding displacement and CYP3A inhibition in the pharmacokinetics of nifedipine in rats — animal studyView study →}, and in healthy volunteers baicalin altered the pharmacokinetics of rosuvastatin, a substrate of the OATP1B1 transporter ^{34Reference 34Fan et al. · 2008RCTThe effect of herbal medicine baicalin on pharmacokinetics of rosuvastatin, a substrate of OATP1B1 — randomised human studyView study →}, so caution is warranted with narrow-therapeutic-index drugs cleared by CYP3A4 or those transporters ^{32Reference 32Zhou et al. · 2021ReviewDrug–herb interactions between Scutellaria baicalensis and pharmaceutical drugs — reviewView study →}. In traditional practice it is avoided in cold or deficiency-type patterns.

Bleeding/antiplatelet interactions have not been formally assessed in this package; because skullcap flavonoids act on arachidonic-acid (COX/LOX) pathways, theoretical caution with anticoagulant or antiplatelet therapy is reasonable, but there are no human data either way. There is no ESCOP, EMA/HMPC or German Commission E monograph for S. baicalensis, so its safety and efficacy have not been assessed by those bodies.