Wogonin

Wogonin at a Glance

Wogonin is a monomethoxy flavone (5,7-dihydroxy-8-methoxyflavone) and one of the free-B-ring flavones largely unique to the genus Scutellaria. It is a characteristic constituent of the dried root of Chinese skullcap (Scutellaria baicalensis, Huang Qin), where it accompanies the far more abundant baicalin and baicalein, and it also occurs in the aerial parts of American skullcap (S. lateriflora) ^{10,12Reference 10Cole IB et al. · 2008Comparisons of Scutellaria baicalensis, Scutellaria lateriflora and Scutellaria racemosa: genome size, antioxidant potential and phytochemistryView study →Reference 12Wang ZL et al. · 2018ReviewA comprehensive review on phytochemistry, pharmacology, and flavonoid biosynthesis of Scutellaria baicalensisView study →}.

Its signature — and the reason it earns a page of its own — is that it is a positive modulator at the benzodiazepine site of the GABA-A receptor: the same nervine mechanism that gives the skullcaps their traditional calming reputation. In rodents this produces a diazepam-like anxiolytic effect, but, notably, without the sedation, muscle-relaxation or dependence that define the classical benzodiazepines ^{1,2Reference 1Hui KM et al. · 2002Anxiolytic effect of wogonin, a benzodiazepine receptor ligand isolated from Scutellaria baicalensis GeorgiView study →Reference 2Tai MC et al. · 2005Therapeutic potential of wogonin: a naturally occurring flavonoidView study →}. Around that core sit well-replicated anti-inflammatory and antiallergic actions (NF-κB suppression, eosinophil apoptosis), direct antiviral activity, and a large pro-apoptotic anticancer literature ^{4,5,6,8Reference 4Lee W et al. · 2015In vitroAnti-inflammatory effects of baicalin, baicalein, and wogonin in vitro and in vivoView study →Reference 5Lucas CD et al. · 2015Wogonin induces eosinophil apoptosis and attenuates allergic airway inflammationView study →Reference 6Banik K et al. · 2022Systematic reviewWogonin and its analogs for the prevention and treatment of cancer: a systematic reviewView study →Reference 8Guo Q et al. · 2007In vitroAnti-hepatitis B virus activity of wogonin in vitro and in vivoView study →}.

The honest headline is that almost all of this is preclinical — cell and rodent work on the isolated molecule. There are no controlled human efficacy trials of wogonin, and its human safety at purified doses is not established.

GABA-A Benzodiazepine-Site Modulation — The Anxiolytic Signature

This is the defining pharmacology of wogonin and the mechanism that ties it to the skullcaps’ nervine tradition. In the foundational study, wogonin bound the benzodiazepine site (BZD-S) of the GABA-A receptor complex with an affinity (Kᵢ) of about 0.92 µM, and in electrophysiological recordings it enhanced the GABA-activated chloride current in rat dorsal-root-ganglion neurons and in Xenopus oocytes expressing recombinant GABA-A receptors — an enhancement partly reversed by the benzodiazepine-site antagonist flumazenil (Ro15-1788) ^{1Reference 1Hui KM et al. · 2002Anxiolytic effect of wogonin, a benzodiazepine receptor ligand isolated from Scutellaria baicalensis GeorgiView study →}.

The behavioural picture matched the receptor pharmacology. Oral wogonin (7.5–30 mg/kg) produced a dose-dependent, diazepam-like anxiolytic response in the elevated plus-maze, and that effect was blocked by co-administration of flumazenil — confirming it runs through the benzodiazepine site. Crucially, in the same animals wogonin showed no signs of sedation (holeboard test) and no myorelaxant effect (horizontal-wire test), and its acute toxicity was low (oral LD₅₀ ≈ 3.9 g/kg in mice) ^{1Reference 1Hui KM et al. · 2002Anxiolytic effect of wogonin, a benzodiazepine receptor ligand isolated from Scutellaria baicalensis GeorgiView study →}.

That combination — genuine anxiolysis via positive allosteric modulation of GABA-A, decoupled from the sedative/myorelaxant/amnestic burden of benzodiazepines — is exactly why wogonin has been repeatedly floated as a template for “next-generation” anxiolytics ^{2Reference 2Tai MC et al. · 2005Therapeutic potential of wogonin: a naturally occurring flavonoidView study →}. The load-bearing caveat is equally clear: this is a rodent and receptor-level result. There is no controlled human anxiety trial of isolated wogonin, and whether an oral human dose reaches anxiolytic brain concentrations is a pharmacokinetic question the isolate has not fully answered ^{3Reference 3Fong SYK et al. · 2017AnimalBrain uptake of bioactive flavones in Scutellariae Radix and its relationship to anxiolytic effect in miceView study →}.

What It's Used For

Beyond the anxiolytic signature, wogonin has a broad and internally consistent preclinical profile. The discipline is that the evidence splits by how far it has travelled — a receptor-level and in-vivo anxiolytic story, robust in-vitro/in-vivo anti-inflammatory and antiallergic work, a very large but entirely preclinical anticancer literature, and narrower antiviral and antioxidant signals.

Evidence by IndicationStrength of support · Beta

Support is an experimental score — weighted by study type (human > animal > in vitro) and volume. A beta, not a validated metric. No application here has human efficacy data, so scores reflect preclinical depth and are capped accordingly; read the per-row basis.

01Anxiolytic (GABA-A Modulation)Promising52%Direct BZD-site binding + GABA-current potentiation + in-vivo EPM, flumazenil-reversible ^{1,2Reference 1Hui KM et al. · 2002Anxiolytic effect of wogonin, a benzodiazepine receptor ligand isolated from Scutellaria baicalensis GeorgiView study →Reference 2Tai MC et al. · 2005Therapeutic potential of wogonin: a naturally occurring flavonoidView study →}

02Anti-Inflammatory / AntiallergicPromising48%Isolate NF-κB/COX-2 suppression in vitro + in vivo; eosinophil apoptosis in a mouse airway model ^{4,5Reference 4Lee W et al. · 2015In vitroAnti-inflammatory effects of baicalin, baicalein, and wogonin in vitro and in vivoView study →Reference 5Lucas CD et al. · 2015Wogonin induces eosinophil apoptosis and attenuates allergic airway inflammationView study →}

03Anticancer / Pro-ApoptoticShaky44%Large cell/animal apoptosis literature + two systematic reviews; no human data ^{6,7Reference 6Banik K et al. · 2022Systematic reviewWogonin and its analogs for the prevention and treatment of cancer: a systematic reviewView study →Reference 7Kim MS et al. · 2013Wogonin induces apoptosis by suppressing E6 and E7 expressions and activating intrinsic signaling pathways in HPV-16 cervical cancer cellsView study →}

04Antiviral (Anti-HBV)Shaky30%Isolate anti-hepatitis-B activity in vitro and in vivo ^{8Reference 8Guo Q et al. · 2007In vitroAnti-hepatitis B virus activity of wogonin in vitro and in vivoView study →}

05AntioxidantShaky26%Constituent-level radical scavenging across Scutellaria species (in vitro) ^{10Reference 10Cole IB et al. · 2008Comparisons of Scutellaria baicalensis, Scutellaria lateriflora and Scutellaria racemosa: genome size, antioxidant potential and phytochemistryView study →}

Mechanisms

The GABA-A benzodiazepine-site modulation is the load-bearing, molecule-specific mechanism — direct, flumazenil-reversible and tied to an in-vivo behavioural effect. The NF-κB axis is shared with its sibling flavones and underlies most of the anti-inflammatory, antiallergic and anticancer signals.

Pharmacokinetics

Wogonin is a lipophilic aglycone, which is central to its CNS story: the free flavone crosses the blood–brain barrier far more readily than its polar glucuronide, and brain uptake of the Scutellaria aglycones (wogonin included) correlates with the anxiolytic effect ^{3Reference 3Fong SYK et al. · 2017AnimalBrain uptake of bioactive flavones in Scutellariae Radix and its relationship to anxiolytic effect in miceView study →}. Systemically, however, its free fraction is limited by extensive phase-II metabolism: in rats wogonin is rapidly and heavily glucuronidated — chiefly to wogonoside (wogonin 7-O-glucuronide) — is highly plasma-protein-bound, distributes widely into tissues and is eliminated quickly, with substantial biliary/enterohepatic handling ^{9Reference 9Talbi A et al. · 2014AnimalPharmacokinetics, tissue distribution, excretion and plasma protein binding studies of wogonin in ratsView study →}. The practical consequence is the familiar flavone-aglycone problem: oral bioavailability of the free molecule is low, so in-vitro potencies do not straightforwardly translate to systemic exposure. Robust human ADME — Cₘₐₓ, half-life and an oral bioavailability figure for isolated wogonin — is not well established; the quantitative PK is rodent, and human intake is as one flavone within a whole skullcap matrix ^{9Reference 9Talbi A et al. · 2014AnimalPharmacokinetics, tissue distribution, excretion and plasma protein binding studies of wogonin in ratsView study →}.

Clinical Trials

There are no controlled clinical efficacy trials of isolated wogonin. Within skullcap chemistry, human trials have gone to other constituents — baicalein reached Phase I/IIa and oroxylin A completed a Phase I — but wogonin itself has not entered human efficacy testing, and all of the applications above rest on cell and animal work.

Last checked: July 2026.

Isolate vs. Plant Studies

Wogonin is a case where the evidence is overwhelmingly the isolated molecule — a strength for mechanism, a limit for real-world relevance. The anxiolytic receptor/behaviour work ^{1Reference 1Hui KM et al. · 2002Anxiolytic effect of wogonin, a benzodiazepine receptor ligand isolated from Scutellaria baicalensis GeorgiView study →}, the anti-inflammatory vascular study ^{4Reference 4Lee W et al. · 2015In vitroAnti-inflammatory effects of baicalin, baicalein, and wogonin in vitro and in vivoView study →}, the eosinophil-apoptosis airway model ^{5Reference 5Lucas CD et al. · 2015Wogonin induces eosinophil apoptosis and attenuates allergic airway inflammationView study →}, the anti-HBV work ^{8Reference 8Guo Q et al. · 2007In vitroAnti-hepatitis B virus activity of wogonin in vitro and in vivoView study →} and the anticancer literature ^{6,7Reference 6Banik K et al. · 2022Systematic reviewWogonin and its analogs for the prevention and treatment of cancer: a systematic reviewView study →Reference 7Kim MS et al. · 2013Wogonin induces apoptosis by suppressing E6 and E7 expressions and activating intrinsic signaling pathways in HPV-16 cervical cancer cellsView study →} all test purified wogonin (usually against cell lines or in rodents). What is missing is the other side: no human trial isolates wogonin’s contribution. The controlled human data that exist for skullcap chemistry are for other single compounds (baicalein tablets, oroxylin A) or for multi-herb combination products, never for wogonin, and never for the crude root on its own ^{6Reference 6Banik K et al. · 2022Systematic reviewWogonin and its analogs for the prevention and treatment of cancer: a systematic reviewView study →}. In the traditional nervine context of American skullcap, the GABA-A benzodiazepine-site story is shared across several flavones — baicalin and baicalein are also BZD-site binders — so wogonin is one contributor among several, not the sole active ^{11Reference 11Awad R et al. · 2003Phytochemical and biological analysis of skullcap (Scutellaria lateriflora L.): a medicinal plant with anxiolytic propertiesView study →}. The correct framing: strong isolate mechanism, especially for anxiolysis; no whole-plant or human efficacy evidence attributable to wogonin specifically.

Prevalence in Nature

Wogonin is one of the free-B-ring flavones largely restricted to the genus Scutellaria — flavones lacking the usual B-ring hydroxyl and instead carrying an 8-methoxy group, a chemotype the genus produces through a root-specific biosynthetic route ^{12Reference 12Wang ZL et al. · 2018ReviewA comprehensive review on phytochemistry, pharmacology, and flavonoid biosynthesis of Scutellaria baicalensisView study →}. Its richest source is the dried root of Chinese skullcap (Scutellaria baicalensis, Huang Qin), where it makes up roughly 1.3% of dry weight — a minor partner to the dominant baicalin (~8–12%), its aglycone baicalein (~5%) and wogonin’s own glucuronide wogonoside (~3.5%) ^{12Reference 12Wang ZL et al. · 2018ReviewA comprehensive review on phytochemistry, pharmacology, and flavonoid biosynthesis of Scutellaria baicalensisView study →}. Much of the root’s wogonin is in fact stored as wogonoside and liberated as the free aglycone by hydrolysis during processing and digestion.

It also occurs in the aerial parts of American skullcap (S. lateriflora) and across other Scutellaria species (S. racemosa, S. amoena), quantified in comparative phytochemical surveys of the genus, though generally as a minor flavone rather than a dominant one ^{10Reference 10Cole IB et al. · 2008Comparisons of Scutellaria baicalensis, Scutellaria lateriflora and Scutellaria racemosa: genome size, antioxidant potential and phytochemistryView study →}. These free-B-ring flavones carry much of the antiallergic, anti-inflammatory and antiviral activity ascribed to skullcap ^{12Reference 12Wang ZL et al. · 2018ReviewA comprehensive review on phytochemistry, pharmacology, and flavonoid biosynthesis of Scutellaria baicalensisView study →}.

Major Natural Sources

Source	Plant part	Reported wogonin content
Chinese skullcap (Scutellaria baicalensis)	dried root	~1.3% dry weight 12Reference 12Wang ZL et al. · 2018ReviewA comprehensive review on phytochemistry, pharmacology, and flavonoid biosynthesis of Scutellaria baicalensisView study →
American skullcap (Scutellaria lateriflora)	aerial parts	minor (quantified across the genus) 10Reference 10Cole IB et al. · 2008Comparisons of Scutellaria baicalensis, Scutellaria lateriflora and Scutellaria racemosa: genome size, antioxidant potential and phytochemistryView study →
Other Scutellaria (S. racemosa, S. amoena)	root / aerial parts	present, minor 10Reference 10Cole IB et al. · 2008Comparisons of Scutellaria baicalensis, Scutellaria lateriflora and Scutellaria racemosa: genome size, antioxidant potential and phytochemistryView study →

Percentages are of the dried plant material and vary with species, origin, plant age and post-harvest processing.

Discovery & Synthesis

Wogonin is 5,7-dihydroxy-8-methoxyflavone, named for its occurrence in Scutellaria (the drug “wogon”/Huang Qin) and first characterised as a constituent of the skullcap root; the precise date of its first isolation is not well documented here and is a future research-loop item. Biosynthetically it belongs to the free-B-ring flavone class that is a chemotaxonomic marker of the genus — these 8-methoxy flavones (baicalein, wogonin and their glycosides) are produced largely in the root through a Scutellaria-specific branch of flavone biosynthesis, distinct from the ordinary 4′-hydroxylated flavones of most plants ^{12Reference 12Wang ZL et al. · 2018ReviewA comprehensive review on phytochemistry, pharmacology, and flavonoid biosynthesis of Scutellaria baicalensisView study →}. Manufacture today is by extraction from Scutellaria baicalensis root, typically as part of a flavone fraction and often by liberating the aglycone from its glucuronide wogonoside; there is no significant total-synthesis supply chain, and wogonin is used chiefly as a research chemical and phytochemical reference standard rather than a bulk commercial ingredient.

Patents: not yet researched.

Toxicity & Safety

Wogonin carries a low toxicity flag. Its acute toxicity is genuinely low — an oral LD₅₀ of about 3.9 g/kg in mice — and, importantly, its rodent anxiolytic doses were non-sedating and non-myorelaxant, i.e. it did not reproduce the impairing side-effects of benzodiazepines even while acting at their receptor site ^{1Reference 1Hui KM et al. · 2002Anxiolytic effect of wogonin, a benzodiazepine receptor ligand isolated from Scutellaria baicalensis GeorgiView study →}. It is a minor constituent of a herb (skullcap) with long traditional use. The honest limits are that purified, high-dose human safety has not been characterised, and — as a benzodiazepine-site modulator and a flavone that can affect drug-metabolising enzymes — its interaction profile in people is essentially unstudied.

Safety at a Glance

✅ Low / no toxicity

• Low acute toxicity. Oral LD₅₀ ≈ 3.9 g/kg in mice, and anxiolytic doses were non-sedating and non-myorelaxant in rodents ^{1Reference 1Hui KM et al. · 2002Anxiolytic effect of wogonin, a benzodiazepine receptor ligand isolated from Scutellaria baicalensis GeorgiView study →}.
• Human safety of purified wogonin is not established. Essentially all data are cell and rodent studies; no human safety or dose-finding record exists for the isolate.
• Additive CNS effects are plausible. As a benzodiazepine-site positive modulator it could in principle compound alcohol and other CNS depressants — untested in humans, and more relevant to concentrated extracts than to the trace amount in a whole-herb preparation ^{1Reference 1Hui KM et al. · 2002Anxiolytic effect of wogonin, a benzodiazepine receptor ligand isolated from Scutellaria baicalensis GeorgiView study →}.
• Drug-metabolism interactions uncharacterised for the isolate. Scutellaria free-B-ring flavones can influence CYP and UGT enzymes; wogonin-specific human interaction data are lacking.

Reproductive and developmental safety data for isolated wogonin are not characterised. Pregnancy and lactation decisions belong to the herb or product page where intake is decided, not to this molecule page; no isolate-specific verdict is issued here.

Dosage

There is no established or recommended human dose for isolated wogonin. The figures below are research doses, given to show the exposures at which effects were observed — not a personal recommendation.

Human exposure to wogonin is indirect — as a minor flavone within whole Chinese skullcap or American skullcap preparations, whose flavonoid content varies severalfold between products. These are doses studied in research and are not a personal recommendation.

References

1. Hui KM, Huen MS, Wang HY, Zheng H, Sigel E, Baur R, Ren H, Li ZW, Wong JT, Xue H (2002). Anxiolytic effect of wogonin, a benzodiazepine receptor ligand isolated from Scutellaria baicalensis Georgi. Biochemical Pharmacology. https://pubmed.ncbi.nlm.nih.gov/12392823/
2. Tai MC, Tsang SY, Chang LY, Xue H (2005). Therapeutic potential of wogonin: a naturally occurring flavonoid. CNS Drug Reviews. https://pubmed.ncbi.nlm.nih.gov/16007236/
3. Fong SYK, Li C, Ho YC, Li R, Wang Q, Wong YC, Xue H, Zuo Z (2017). Brain uptake of bioactive flavones in Scutellariae Radix and its relationship to anxiolytic effect in mice. Molecular Pharmaceutics. https://pubmed.ncbi.nlm.nih.gov/28426226/
4. Lee W, Ku SK, Bae JS (2015). Anti-inflammatory effects of baicalin, baicalein, and wogonin in vitro and in vivo. Inflammation. https://pubmed.ncbi.nlm.nih.gov/25249339/
5. Lucas CD, Dorward DA, Sharma S, Rennie J, Felton JM, Alessandri AL, Duffin R, Schwarze J, Haslett C, Rossi AG (2015). Wogonin induces eosinophil apoptosis and attenuates allergic airway inflammation. American Journal of Respiratory and Critical Care Medicine. https://pubmed.ncbi.nlm.nih.gov/25629436/
6. Banik K, Khatoon E, Harsha C, Rana V, Parama D, Thakur KK, Bishayee A, Kunnumakkara AB (2022). Wogonin and its analogs for the prevention and treatment of cancer: a systematic review. Phytotherapy Research. https://pubmed.ncbi.nlm.nih.gov/35102626/
7. Kim MS, Bak Y, Park YS, Lee DH, Kim JH, Kang JW, Song HH, Oh SR, Yoon DY (2013). Wogonin induces apoptosis by suppressing E6 and E7 expressions and activating intrinsic signaling pathways in HPV-16 cervical cancer cells. Cell Biology and Toxicology. https://pubmed.ncbi.nlm.nih.gov/23955116/
8. Guo Q, Zhao L, You Q, Yang Y, Gu H, Song G, Lu N, Xin J (2007). Anti-hepatitis B virus activity of wogonin in vitro and in vivo. Antiviral Research. https://pubmed.ncbi.nlm.nih.gov/17280723/
9. Talbi A, Zhao D, Liu Q, Li J, Fan A, Yang W, Han X, Chen X (2014). Pharmacokinetics, tissue distribution, excretion and plasma protein binding studies of wogonin in rats. Molecules. https://pubmed.ncbi.nlm.nih.gov/24786691/
10. Cole IB, Cao J, Alan AR, Saxena PK, Murch SJ (2008). Comparisons of Scutellaria baicalensis, Scutellaria lateriflora and Scutellaria racemosa: genome size, antioxidant potential and phytochemistry. Planta Medica. https://pubmed.ncbi.nlm.nih.gov/18484546/
11. Awad R, Arnason JT, Trudeau V, Bergeron C, Budzinski JW, Foster BC, Merali Z (2003). Phytochemical and biological analysis of skullcap (Scutellaria lateriflora L.): a medicinal plant with anxiolytic properties. Phytomedicine. https://pubmed.ncbi.nlm.nih.gov/14692724/
12. Wang ZL, Wang S, Kuang Y, Hu ZM, Qiao X, Ye M (2018). A comprehensive review on phytochemistry, pharmacology, and flavonoid biosynthesis of Scutellaria baicalensis. Pharmaceutical Biology. https://doi.org/10.1080/13880209.2018.1492620

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