Thymus vulgaris L. · herb
Evidence tier: traditional
Natural antimicrobial and anti inflammatory herb for respiratory infections, sinusitis, and bronchitis, thymol content makes it an effective cough expectorant
Plausible, and the EMA accepts the plausibility while declining to accept the trials. Thymol and carvacrol are phenolic monoterpenes that partition into microbial membranes and increase permeability, which is a well characterised in vitro antimicrobial mechanism. The proposed respiratory action is spasmolytic and secretolytic, relaxing bronchial smooth muscle and loosening mucus so it can be cleared, which is the classical justification for the productive cough indication. Both are laboratory and pharmacological accounts, not effects demonstrated for thyme on its own in a controlled trial in people, and they should be stated as the reason the traditional use is credible rather than as an explanation for a proven effect.
Traditional use, and the regulator says so in the plainest language available. The EMA HMPC monograph on Thymus vulgaris L. and Thymus zygis L., herba is a TRADITIONAL USE monograph for productive (chesty) coughs associated with colds. The HMPC's stated reason for choosing that category is decisive: although there is insufficient evidence from clinical trials, the effectiveness of these herbal medicines is plausible and there is evidence that they have been used safely in this way for at least 30 years. That is the regulator explicitly declining to credit the trials. The trials people cite for thyme are combination trials, and this is the trap. Kemmerich 2006 (Arzneimittelforschung, 361 outpatients with acute bronchitis, 11 days) tested a fluid extract of THYME PLUS IVY LEAF against placebo, and found faster resolution of coughing fits. Kemmerich 2007 tested a fixed combination of THYME PLUS PRIMROSE ROOT. Both are decent trials of products that are not thyme. Ivy leaf carries its own secretolytic and spasmolytic activity and is a separately monographed herbal medicine in its own right, so a positive result for thyme plus ivy cannot be assigned to the thyme, and the EMA's own assessment noted that the single herb thyme evidence, one comparison against bromhexine, had methodological limitations. Strip out the combinations and what remains for thyme alone is long standing use and a plausible mechanism. That is a traditional grade, not a clinical one. Safety is genuinely unremarkable at the doses in question: thyme is a culinary herb, the EMA registers it for adults and adolescents over 12 with some preparations down to 4 years, and if a cough lasts more than a week the monograph says to see a doctor. There is no LiverTox signal and no meaningful interaction surface at tea or syrup doses. This is a benign ingredient with an overstated file.
EMA registered traditional preparations. Herbal tea: roughly 1 to 2 g of the comminuted herbal substance in 150 ml of boiling water as an infusion, several times daily. Adults and adolescents over 12 for most preparations, with a few registered from 4 years. If symptoms last longer than one week or worsen, a doctor should be consulted. Note that the thyme plus ivy fluid extract used in the Kemmerich trials was dosed at 5.4 ml three times daily and is a DIFFERENT product from thyme tea; its dose does not transfer.
As a syrup or tea: take 2 to 3 times daily during respiratory illness. Thyme syrup (combined with ivy leaf) has strong clinical evidence for acute bronchitis. Use standardised extracts containing 0.03% thymol for reliable dosing.
Food grade quantities are safe for all ages. Medicinal doses (concentrated extracts) should be avoided in pregnancy beyond culinary amounts, thymol has uterotonic activity at high doses. Rare allergic reactions in Lamiaceae sensitive individuals. No significant drug interactions at typical tea doses.
Pregnancy: caution
Breastfeeding: safe
Active compounds: thymol, carvacrol, rosmarinic acid, flavonoids (luteolin, apigenin), p-cymene
Remedies using Thyme · Browse by body system · Check it against what you take
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