Thyme

Thyme contains active compounds (notably thymol and related phenolic monoterpenes) with antimicrobial, antispasmodic, expectorant (mucus-loosening), anti-inflammatory and mild bronchodilating effects. Those properties can reduce cough frequency/intensity and help clear mucus — which is why thyme-based remedies are used for spasmodic and productive coughs (including traditional use for whooping cough). However, most high-quality clinical evidence concerns symptom relief in acute bronchitis / cough, often when thyme is combined with other herbal extracts (e.g., ivy). There is no high-quality evidence that thyme eradicates Bordetella pertussis (the bacterium that causes whooping cough); antibiotics are required for that. MDPI

Representative evidence & mechanisms:

• Thymol & thyme essential oil — reviews summarize antimicrobial, anti-inflammatory and expectorant effects and document in-vitro activity against many respiratory pathogens and biofilms; these mechanisms plausibly reduce cough and help airway clearance. MDPI
• Regulatory/monograph recognition — European herbal regulators and herbal medicine references note thyme’s traditional and clinical use for spastic and productive coughs. European Medicines Agency (EMA)

A. Herbal tea (traditional use / Commission E guidance)

• Typical dose used in herb monographs: 1–2 g (≈¼–½ teaspoon dried herb) in 250 ml (1 cup) hot water, taken several times daily (for example 2–4 times/day) as needed for cough. This dosing is what German monographs and many herbal references list for thyme tea. PeaceHealth

B. Standardized liquid extracts / syrups (used in trials)

• Clinical trials and marketed preparations often use standardized fluid extracts or combined syrups (e.g., Bronchipret® — thyme + ivy). A notable randomized double-blind placebo-controlled trial used 5.4 ml, three times daily for 11 days of a thyme/ivy syrup. Such combination syrups are commonly dosed TID (three times daily) per product labels and trials. If you follow a commercial product, follow the product label dosing. Europe PMC

C. Tinctures / glycerites

• Folk and naturopathic sources describe tinctures, but concentrated essential oil or internal use of essential oil is risky (see warnings). Use tinctures only from reliable sources and follow product labeling or a qualified herbalist/clinician’s advice. myfolkmedicine.com

D. Inhalation / steam

• Steam inhalation with thyme (or thyme oil diluted in steam) is sometimes used to relieve congestion, but caution is required with essential oils (risk of airway irritation and burns). Use mild decoction/scent rather than undiluted oil. Verywell Health

Clinical trials / clinical evidence:

• Kemmerich B., Eberhardt R., Stammer H., 2006 — Arzneimittelforschung
• “Efficacy and tolerability of a fluid extract combination of thyme herb and ivy leaves and matched placebo in adults suffering from acute bronchitis with productive cough.” (prospective double-blind placebo-controlled multicentre trial; syrup 5.4 ml TID for 11 days; showed superiority vs placebo for bronchitis symptoms). Europe PMC
• Bronchipret® / thyme+ivy studies (mechanistic & clinical data) — combination products containing thyme + ivy have both clinical and mechanistic/in-vitro data supporting mucolytic/expectorant and antitussive activity. Example: a 2015 mechanistic paper and several observational/real-world studies on Bronchipret®. These show symptom improvement in acute bronchitis / cough. ScienceDirect

Systematic reviews / mechanistic reviews:

• Molecules (MDPI) review on thymol and thyme essential oil — reviews antimicrobial, anti-inflammatory, expectorant and other relevant actions (useful for mechanism). MDPI
• Thymol antibacterial/antifungal review — summarizes the antimicrobial spectrum and biological activities of thymol (a major thyme constituent) that support respiratory uses. ScienceDirect

Other reputable summaries:

• European Medicines Agency (EMA) assessment report on Thymus vulgaris / essential oil — gives regulatory overview, traditional uses, safety profile and references. European Medicines Agency (EMA)