--- topic: "Mullein" title: "Respiratory Health, Antiviral, and Antimicrobial" order: 1 description: "How mullein's saponins, mucilages, and flavonoids support lung health, fight respiratory pathogens, and calm inflammation" question: "Does mullein help with coughs and lung health?" answer: "There is little evidence that mullein treats coughs or respiratory infections in people; support is lab studies and traditional use." actions: - "For sore throat with dry cough (an EMA-recognized traditional use), steep 1–2 teaspoons of dried leaf or flower per cup for 10–15 minutes [8]." - "Strain leaf tea through a fine cloth or coffee filter; the leaf hairs can irritate the throat." cautions: - "Not enough data exist for pregnancy and breastfeeding, so avoidance is prudent; the EMA traditional use covers only people over 12 [8]." - "Do not smoke mullein leaf for breathing problems; smoking any plant material carries risks." - "The ear-oil trials used a multi-herb formula, so benefit cannot be credited to mullein alone [7]." confidence: 1 confidenceNote: "Antiviral, antibacterial and anti-inflammatory findings are lab-only; the two human RCTs (103 and 171 children) tested a multi-herb ear oil, not respiratory use." evidenceSummary: rctCount: 2 observationalCount: 0 metaAnalysisCount: 0 totalParticipants: "270+" replicated: false newestStudyYear: 2022 references: - id: "1" pmid: "35088467" title: "Health-promoting and disease-mitigating potential of Verbascum thapsus L. (common mullein): A review" authors: "Gupta A, Atkinson AN, Pandey AK, Bishayee A" year: 2022 journal: "Phytotherapy Research" - id: "2" pmid: "12241986" title: "Biological activity of common mullein, a medicinal plant" authors: "Turker AU, Camper ND" year: 2002 journal: "Journal of Ethnopharmacology" - id: "3" pmid: "19828096" title: "Anti-inflammatory properties of the plant Verbascum mallophorum" authors: "Speranza L, Franceschelli S, Pesce M, Menghini L, Patruno A, Vinciguerra I, De Lutiis MA, Felaco M, Felaco P, Grilli A" year: 2009 journal: "Journal of Biological Regulators and Homeostatic Agents" - id: "4" pmid: "21999656" title: "Antiviral effect and mode of action of methanolic extract of Verbascum thapsus L. on pseudorabies virus (strain RC/79)" authors: "Escobar FM, Sabini MC, Zanon SM, Tonn CE, Sabini LI" year: 2012 journal: "Natural Products Research" - id: "5" pmid: "1666504" title: "Antiviral activity of Flos verbasci infusion against influenza and Herpes simplex viruses" authors: "Zgorniak-Nowosielska I, Grzybek J, Manolova N, Serkedjieva J, Zawilinska B" year: 1991 journal: "Archives of Immunology and Therapeutic Experimentation" - id: "6" pmid: "11434846" title: "Efficacy of naturopathic extracts in the management of ear pain associated with acute otitis media" authors: "Sarrell EM, Mandelberg A, Cohen HA" year: 2001 journal: "Archives of Pediatrics and Adolescent Medicine" - id: "7" pmid: "12728112" title: "Naturopathic treatment for ear pain in children" authors: "Sarrell EM, Cohen HA, Kahan E" year: 2003 journal: "Pediatrics" - id: "8" url: "https://www.ema.europa.eu/en/medicines/herbal/verbasci-flos" title: "EU herbal monograph on Verbasci flos (mullein flower)" authors: "European Medicines Agency" year: 2018 journal: "European Medicines Agency Herbal Monographs" --- Mullein (*Verbascum thapsus*) is a tall, woolly-leaved plant that has been used across European, Native American, and Middle Eastern traditions for centuries as a primary remedy for coughs, bronchitis, and congested lungs. Its soft leaves contain saponins that thin mucus and stimulate its expulsion, while the plant's mucilages coat and soothe irritated airways [1]. In vitro studies have since confirmed what traditional herbalists observed: mullein extracts show meaningful antiviral activity against influenza and herpes-family viruses, and antibacterial action against several respiratory pathogens [2][5]. The European Medicines Agency formally recognizes its traditional use for relief of sore throats with dry coughs [8]. ## How Mullein Works Mullein's medicinal activity comes from several classes of compounds that act through distinct but complementary mechanisms: saponins, mucilaginous polysaccharides, iridoid glycosides, phenylethanoid glycosides (principally verbascoside), and flavonoids (apigenin, luteolin, quercetin) [1]. ### Expectorant and Demulcent Action The two most immediately relevant properties for lung health are its expectorant and demulcent effects. Saponins in mullein lower the surface tension of bronchial secretions, making thick mucus easier to mobilize and cough up — this is the same mechanism behind many over-the-counter expectorants. The mucilaginous polysaccharides do something different: they form a viscous, slippery coating over irritated mucous membranes in the throat and airways, reducing friction and calming the cough reflex. This combination makes mullein particularly useful for dry, irritating coughs as well as productive coughs with thick secretions [1][8]. ### Antiviral Activity Multiple in vitro studies have documented mullein's antiviral effects. Aqueous infusions of mullein flowers (Flos verbasci) reduced influenza A and B virus titers by 1–3 log units and reduced herpes simplex virus (HSV) titers by approximately 2.3 log units — a virucidal effect confirmed at 300 µg/mL [5]. A later study on pseudorabies virus (a herpesvirus model) found a 50% inhibitory concentration (IC50) of 35 µg/mL for plaque formation, with a selectivity index of 31–40 (meaning the antiviral dose was well below toxic concentrations) [4]. Importantly, the mechanism appears to be disruption of viral entry: when the extract was incubated with virus before cell contact, viral plaques were inhibited by 99%; when cells were pretreated before exposure, inhibition was 70%. This suggests the bioactive compounds act by interfering with viral attachment or fusion rather than by general cytotoxicity [4]. ### Anti-Inflammatory Mechanisms Verbascoside, a phenylethanoid glycoside found throughout the Verbascum genus, is the primary anti-inflammatory compound. At 100 µM, it significantly reduces expression of inducible nitric oxide synthase (iNOS) and decreases extracellular superoxide radical production in stimulated immune cells [3]. The mechanism runs through inhibition of NF-kappaB-dependent iNOS activation — the same inflammatory signaling pathway targeted by many anti-inflammatory drugs, reached here through a gentler botanical route. Mullein's flavonoids (quercetin, luteolin) additionally inhibit TNF-alpha-driven adhesion molecule expression, further dampening the inflammatory response in affected tissue [1]. ### Antibacterial Properties Mullein extracts show activity against bacteria frequently involved in respiratory infections. Water, ethanol, and methanol extracts have all demonstrated inhibition of *Klebsiella pneumoniae*, *Staphylococcus aureus*, *Staphylococcus epidermidis*, and *Escherichia coli* in laboratory testing, with the aqueous extract showing the strongest antibacterial activity [2]. While these are in vitro findings and do not directly translate to clinical efficacy, they support mullein's traditional reputation as a plant that helps resolve — not merely suppress — respiratory infections. ## Practical Use **Forms:** Mullein is used as a loose-leaf tea (1–2 teaspoons of dried leaf or flower per cup, steeped 10–15 minutes), as a tincture (typically 2–4 mL, up to three times daily), and in capsule form. Tea is the most traditional preparation and preserves the mucilaginous compounds well. Mullein leaf tea should be strained through a fine cloth or coffee filter — the fine leaf hairs can irritate the throat if not removed. **Ear oil:** A traditional preparation for ear infections involves infusing mullein flowers (often with garlic) in warm olive oil. Two randomized controlled trials found this formula as effective as anesthetic ear drops for pain relief in children with acute otitis media [6][7]. **Smoking:** Dried mullein leaf has a long tradition of being smoked for respiratory complaints — a seemingly paradoxical but genuinely traditional practice for acute bronchospasm. Not recommended for general use given the risks associated with smoking any plant material. **Cautions:** Mullein is well-tolerated at typical doses with no significant adverse events reported in clinical use. Not enough data exists for pregnancy and breastfeeding, so avoidance is prudent during those periods. The leaf hairs (trichomes) must be strained from tea preparations. See our [marshmallow root page](/marshmallow-root/gut-and-respiratory-healing) for another demulcent herb with complementary action in the respiratory tract, and our [echinacea page](/echinacea/immune-support-and-cold-prevention) for an herb with more extensive clinical trial evidence for acute upper respiratory infections. ## Evidence Review ### In Vitro Antiviral Studies **Zgorniak-Nowosielska et al. (1991)** conducted one of the foundational studies on mullein's antiviral properties using lyophilized infusions from *Verbascum thapsiforme* flowers [5]. The extract was tested against influenza A strains (H1N1 and H3N2), influenza B, fowl plague virus, and herpes simplex virus type 1 (HSV-1). Against influenza strains, viral titers were reduced by 1–3 log units, representing a 10- to 1000-fold decrease in infectious virus particles. Against HSV-1, the titer reduction was approximately 2.3 log units with direct virucidal activity demonstrated at 300 µg/mL — meaning the extract killed virus on contact rather than merely inhibiting replication. The chemical analysis confirmed the presence of flavonoids, iridoids, phenolic acids, saponins, amino acids, and free sugars. **Escobar et al. (2012)** provided mechanistic detail using methanolic extract of *Verbascum thapsus* against pseudorabies virus (a herpesvirus) [4]. The 50% inhibitory concentration for plaque formation was 35 µg/mL, with a selectivity index of 31.4–40.7. The crucial mechanistic finding came from a time-of-addition experiment: when the extract was added to virus before the cells were infected, plaque inhibition reached 99%; when cells were pretreated before viral exposure, inhibition was 70%; but when the extract was added after the adsorption phase was complete, no inhibition occurred. This defines the site of action as the viral entry step — the extract interferes with viral adsorption to and/or fusion with host cells. This is pharmacologically significant because blocking viral entry is a more complete barrier than inhibiting post-entry replication. ### Antibacterial Evidence **Turker and Camper (2002)** tested mullein extracts against a range of bacteria [2]. Water, ethanol, and methanol extracts all showed antibacterial activity against *Klebsiella pneumoniae* (a cause of bacterial pneumonia), *Staphylococcus aureus* (including respiratory strains), *S. epidermidis*, and *E. coli*. Aqueous extracts showed the strongest antibacterial effect. All extracts also inhibited tumor formation in a potato disc bioassay, suggesting additional bioactive properties. The authors noted dose-dependent cytotoxicity at high concentrations, consistent with other bioactive plant extracts. This study provides the primary pharmacological basis for mullein's documented traditional use in respiratory bacterial infections. ### Anti-Inflammatory Mechanism **Speranza et al. (2009)** isolated the anti-inflammatory mechanism using purified verbascoside from *Verbascum mallophorum* [3]. Human THP-1 monocytic cells stimulated with LPS and interferon-gamma (a standard model of acute inflammation) were treated with 100 µM verbascoside. The results showed significant decreases in iNOS expression, iNOS enzymatic activity, and extracellular superoxide anion production. The mechanistic conclusion was that verbascoside suppresses NF-kappaB-dependent iNOS transcription, which blocks the nitric oxide arm of the acute inflammatory cascade. Because excessive nitric oxide production damages airway tissue during respiratory infections, this mechanism is directly relevant to mullein's traditional use for inflamed, irritated respiratory tracts. ### Clinical Evidence: Ear Infections **Sarrell et al. (2001)** conducted a randomized controlled trial in 103 children (ages 6–18) with acute otitis media (middle ear infection) [6]. Participants received either a naturopathic ear drop formula containing mullein (*Verbascum thapsus*), garlic (*Allium sativum*), calendula, and St. John's wort in olive oil, or standard anesthetic ear drops (Auralgan). Both groups showed significant improvement in pain scores (p = 0.007), and the naturopathic formula performed comparably to the pharmaceutical anesthetic. No adverse events were reported. **Sarrell et al. (2003)** followed with a larger double-blind RCT in 171 children using four arms: herbal extract alone, herbal extract plus anesthetic, herbal extract plus amoxicillin, and anesthetic plus amoxicillin [7]. The herbal-only group performed comparably to the other groups for pain management. Notably, 80% of the pain reduction appeared self-limited regardless of treatment, which the authors attributed to the natural resolution course of otitis media. No adverse events were documented in the herbal arms. Both trials are limited by the fact that mullein was part of a multi-herb formula — no trial has isolated mullein as a single agent for ear infections — but the consistent positive findings across both studies lend credibility to this traditional application. ### Regulatory Recognition The European Medicines Agency's herbal monograph for Verbasci flos (mullein flower) recognizes its use for "relief of sore throat associated with dry cough and cold" in adults and adolescents over 12 years of age [8]. The evidence classification is "traditional use" — defined as at least 30 years of documented therapeutic use (including at least 15 years within the EU) without documented safety signals. This classification acknowledges that rigorous randomized controlled trials specific to mullein as a single agent are lacking while affirming a long safety track record. ### Strength of Evidence The antiviral and antibacterial evidence for mullein is in vitro only — there are no randomized trials testing mullein in isolation for respiratory infections in humans. The anti-inflammatory mechanisms are demonstrated in cell studies. The two human trials showing benefit are in a combined herbal formula for ear pain, not pure mullein. The expectorant and demulcent mechanisms are biologically plausible and consistent with the plant's chemical composition, but have not been quantified in clinical endpoints. Mullein is best understood as a well-tolerated, traditionally validated respiratory herb with a solid mechanistic rationale and some indirect human evidence — appropriate for symptomatic support of coughs, bronchitis, and throat irritation, while large-scale clinical trials remain absent.