Mullein

Metadata

Approved Indications

Commission E

• Catarrhs of the respiratory tract (Katarrhe der Luftwege)

ESCOP

• No ESCOP monograph exists for Verbascum densiflorum / V. thapsus

EMA/HMPC

• Traditional use: As an expectorant in cough associated with common cold
• Classification based on long-standing traditional use (not well-established use)
• EMA monograph covers Verbascum thapsus L., V. densiflorum Bertol., and V. phlomoides L.

Agreement/Disagreement Between Bodies

Commission E and EMA are broadly aligned on the respiratory catarrh/cough indication, though Commission E uses “catarrhs of the respiratory tract” while EMA specifies “expectorant in cough associated with cold.” ESCOP has not issued a monograph, which represents a gap rather than a disagreement. Neither body grants well-established use status, reflecting the absence of clinical trial evidence.

Conditions Treated

Primary

• Respiratory catarrh
• Cough associated with common cold (dry and productive)
• Upper respiratory tract irritation

Secondary

• Sore throat and pharyngeal irritation
• Mild bronchitis (traditional use)

Traditional/Historical

• Ear infections (mullein oil drops — traditional folk remedy, not covered by regulatory monographs)
• Skin inflammation and wound healing (external use of flowers)
• Hemorrhoids (folk medicine)
• Urinary tract complaints (folk medicine, not substantiated)

Mechanism of Action

1. Demulcent/Mucoprotective (Mucilage)

• Mucilage polysaccharides (~3% of dried flowers) form a protective film over irritated respiratory mucosa
• Shields sensory nerve endings from irritants, reducing the cough reflex
• Local/topical mechanism, not requiring systemic absorption
• Similar principle to marshmallow (Althaea officinalis) and plantain (Plantago lanceolata), though lower mucilage content

2. Expectorant (Saponins)

• Verbascosaponin and related triterpenoid saponins stimulate bronchial secretion via reflex mechanisms
• Increased mucus production helps hydrate viscous secretions, facilitating expectoration
• This provides a mild secretolytic effect complementary to the demulcent action

3. Anti-inflammatory

• Verbascoside (acteoside): Phenylethanoid glycoside with demonstrated anti-inflammatory and antioxidant activity in vitro
• Inhibits pro-inflammatory pathways including NF-kB
• Aucubin: Iridoid glycoside with anti-inflammatory and mild antimicrobial properties (also found in plantain)

4. Antimicrobial

• Verbascoside and saponins demonstrate mild antibacterial activity against respiratory pathogens in vitro
• Aucubin aglycone (aucubigenin) shows activity against Staphylococcus aureus
• Clinical relevance at therapeutic doses remains unconfirmed

Key Active Constituents

• Mucilage polysaccharides (~3%): Galactomannans, arabinogalactans
• Saponins: Verbascosaponin (triterpenoid type)
• Iridoid glycosides: Aucubin, catalpol (shared with plantain)
• Phenylethanoid glycosides: Verbascoside (acteoside), forsythoside B
• Flavonoids: Hesperidin, rutin, apigenin, luteolin glycosides
• Essential oil (traces)

Clinical Evidence Summary

Clinical Trial Evidence

• No randomized, placebo-controlled clinical trials have been identified for mullein flower monotherapy in respiratory conditions
• The Commission E and EMA approvals rely entirely on traditional use documentation and pharmacological plausibility
• This represents one of the weakest clinical evidence bases among respiratory herbs in this collection

Preclinical/In Vitro Evidence

• Anti-inflammatory activity of verbascoside confirmed in multiple in vitro models
• Antimicrobial activity demonstrated against selected respiratory pathogens
• Saponin-mediated secretolytic activity demonstrated in animal models
• Antioxidant activity of phenolic compounds confirmed

Traditional Use Evidence

• Documented use in European folk medicine for centuries
• Listed in numerous traditional European pharmacopoeias and herbals
• Mullein flower tea (Königskerzenblütentee) is a traditional component of breast/chest tea blends (Brusttee) in German-speaking countries
• Mullein oil (flowers macerated in olive oil) has a long folk tradition for earache, though this use is outside the scope of regulatory monographs

Evidence Assessment

The pharmacological rationale for mullein as a respiratory demulcent/expectorant is plausible based on its mucilage and saponin content, and the constituent verbascoside has demonstrable anti-inflammatory properties. However, the complete absence of clinical trial data means efficacy remains unproven by modern standards. The evidence gap is significant.

European vs US/Anglophone Consensus

Notable difference: European pharmacopoeial tradition emphasizes the flowers (Verbasci flos), while Anglophone herbal tradition more commonly uses leaves. The regulatory monographs (Commission E, EMA) specifically cover the flowers.

Safety Profile

Contraindications

• Hypersensitivity to Verbascum species or other Scrophulariaceae
• No other contraindications known

Drug Interactions

• No known drug interactions documented
• No clinically significant interactions expected based on pharmacological profile

Side Effects

• Very rare at therapeutic doses
• Minor gastrointestinal discomfort possible but uncommon
• Contact dermatitis from handling fresh plant material reported rarely
• Very good safety profile overall

Pregnancy/Lactation

• Pregnancy: No specific safety concerns identified from traditional use. However, formal safety studies are lacking. EMA monograph does not recommend use during pregnancy due to insufficient data.
• Lactation: Insufficient data. EMA monograph does not recommend use during breastfeeding due to lack of safety data.
• Not recommended for children under 12 years (EMA) due to insufficient data, though traditional use in children has occurred without reported problems.

Clinical Dosage

Herbal Tea (Infusion)

Other Preparations

Preparation Notes

• Important: Mullein flower infusions must be strained carefully through a fine cloth or paper filter to remove fine staminal hairs, which can cause throat irritation if ingested
• Often used in combination with thyme, marshmallow, plantain, or mallow in traditional chest tea blends
• For cough: Drink warm, several times daily

Duration

• Acute use: 7-14 days for cough associated with cold
• If symptoms persist beyond 7 days, medical consultation is recommended (EMA)

Sources

• German Commission E Monograph: Verbasci flos
• EMA/HMPC Community Herbal Monograph on Verbascum thapsus L., V. densiflorum Bertol., V. phlomoides L., flos
• EMA/HMPC Assessment Report on Verbascum thapsus L., V. densiflorum Bertol., V. phlomoides L., flos
• European Pharmacopoeia: Verbasci flos monograph
• Turker AU, Camper ND. Biological activity of common mullein, a medicinal plant. J Ethnopharmacol. 2002;82(2-3):117-125
• Slagowska A, et al. Qualitative and quantitative analysis of phenolic compounds in Verbascum densiflorum and V. phlomoides. Planta Med. 2000
• Arzneipflanzenlexikon: Verbascum densiflorum (arzneipflanzenlexikon.info)
• Wichtl M (ed). Herbal Drugs and Phytopharmaceuticals. 3rd ed. Stuttgart: Medpharm; 2004

Connections

• Compare demulcent mechanism with Marshmallow (Althaea officinalis — higher mucilage content, stronger demulcent)
• Shares iridoid glycoside constituents (aucubin, catalpol) with Plantain (Plantago lanceolata)
• Often combined with Thyme in European chest tea blends for productive cough
• Compare with Ivy Leaf for expectorant action (ivy leaf has much stronger clinical evidence)
• Compare traditional use evidence level with Linden Flower (both primarily traditional use category)