Shirazi thyme (Zataria multiflora)
Also called Zataria multiflora, Zataria multiflora Boiss., Avishan-e Shirazi.
Best grade C across 8 graded outcomes Botanical Last checked
The short answer
From 12 sourcesShirazi thyme is a Persian medicinal herb, tested as an extract at 3-10 mg per kg of body weight a day or as 1,400 mg of powder a day. Small Iranian trials report fewer gut symptoms in ulcerative colitis, better breathing scores in asthma and COPD, and lower insulin resistance in fatty liver disease, all grade C or D.
Every graded outcome on this page
8 rows · line = participants- CGrade CBlood inflammatory markersInflammation markersn 1,262
- CGrade CRespiratory symptoms, lung function and oxidative stressBreathingn 394
- CGrade CColitis symptoms and antioxidant markersUlcerative colitisn 92
- CGrade CDisease activity, digestive symptoms and inflammation markersUlcerative colitisn 92
- CGrade CInsulin resistance and liver markers in fatty liver diseaseFatty livern 85
- DGrade DLung function, symptoms and inhaler use in COPDCOPDn 45
- DGrade DAsthma symptoms and lung functionAsthman 36
- DGrade DBlood inflammation markers in asthmaAsthman 36
- 5 more graded outcomes, in the evidence chapter
Key facts
- Ulcerative colitis
- In one 92-person placebo-controlled trial, 6 mg/kg/day for 2 months improved bowel frequency, urgency and symptom scores, but the partial Mayo score did not change12
- Breathing
- A 2025 meta-analysis of 9 small trials (394 people) found less cough and wheeze and better lung-function values than control5
- Fatty liver
- In an 85-patient placebo-controlled trial, 700 mg of powder twice daily for 12 weeks lowered insulin resistance and blood pressure versus placebo, but ALT and ultrasound fat grade did not differ from placebo9
- Asthma caveat
- The 36-person asthma trial reported every comparison against baseline, not against placebo7
What it is
Shirazi thyme (Zataria multiflora) is a thyme-like herb from Persian medicine, used for digestive and breathing complaints.
Forms, side by side
2 forms named in our sources. The rest show what our data holds, and say plainly where it holds nothing yet.
Shirazi thyme (Zataria multiflora) forms compared
2 forms| 2 forms | Leaf and stem extract (hydroalcoholic) | Powdered herb (capsules) |
|---|---|---|
| Absorption in people | No human absorption data in the cited studies.27 | No human absorption data in the cited studies.9 |
| GI tolerance | Adverse events are not described in the trial abstracts. In the asthma trial, haemoglobin and haematocrit fell with 10 mg/kg/day.17 | Adverse events are not described in the trial abstract.9 |
| Studied for | Ulcerative colitis symptoms, asthma and COPD | Insulin resistance and liver markers in fatty liver disease |
- Leaf and stem extract (hydroalcoholic)
- Powdered herb (capsules)
What the human research says
Human trials only, one row per outcome. The form line shows what each trial actually tested. Grades follow our evidence-grading policy.
Trial map
8 graded outcomes, largest study first8 graded outcomes: 6 improved, 2 mixed. The largest, a 2025 meta-analysis of 1,262 people on blood inflammatory markers, found an improvement.
1Blood inflammatory markers
Improved · Grade C · Meta-analysis, 1,262 people, 2025
People with various conditions (10 trials, Iran)
Dose, result and source| Outcome | Found | People | Study | Who was studied |
|---|---|---|---|---|
| Blood inflammatory markers | Improved | 1,262 | Grade C · Meta-analysis, 2025 | People with various conditions (10 trials, Iran) |
| Respiratory symptoms, lung function and oxidative stress | Improved | 394 | Grade C · Meta-analysis, 2025 | People with respiratory conditions (9 trials, Iran) |
| Disease activity, digestive symptoms and inflammation markers | Mixed | 92 | Grade C · RCT, 2025 | Adults with ulcerative colitis (multicentre, Iran) |
| Colitis symptoms and antioxidant markers | Improved | 92 | Grade C · RCT, 2025 | Adults with mild-to-moderate ulcerative colitis (multicentre, Iran) |
| Insulin resistance and liver markers in fatty liver disease | Mixed | 85 | Grade C · RCT, 2018 | Adults with non-alcoholic fatty liver disease (Shiraz, Iran) |
| Lung function, symptoms and inhaler use in COPD | Improved | 45 | Grade D · RCT, 2024 | Adults with COPD (Mashhad, Iran) |
| Blood inflammation markers in asthma | Improved | 36 | Grade D · RCT, 2022 | Adults with asthma (Mashhad, Iran) |
| Asthma symptoms and lung function | Improved | 36 | Grade D · RCT, 2020 | Adults with asthma (Mashhad, Iran) |
Every graded row
8 rowsShowing 8 of 8 outcomes. Human trials only.
CGrade CBlood inflammatory markersInflammation markersLower CRP and IL-6Meta-analysis · 10 studies
n 1,262 · 2025
Improved IL-2, IL-4, IL-5, IL-6, IL-8, CRP, EGF, VEGF and MCP-1 fell and IFN-gamma and IL-10 rose; TNF-alpha did not change.
- Design
- Meta-analysis, 10 studies, n = 1,262, 2025
- Population
- People with various conditions (10 trials, Iran)
- Form
- Zataria multiflora or its constituent carvacrol
- Dose
- Varied by trial
- Duration
- Varied by trial
- Source
- Reference 6 · PubMed 39992592 (opens PubMed)
CGrade CRespiratory symptoms, lung function and oxidative stressBreathingLess cough and wheezeMeta-analysis · 9 studies
n 394 · 2025
Improved Cough (WMD -0.99), day, night and chest wheeze fell, and FEV (WMD 11.38), FVC (16.01) and peak flow (8.78) rose vs control; malondialdehyde fell (SMD -1.54) and catalase rose.
- Design
- Meta-analysis, 9 studies, n = 394, 2025
- Population
- People with respiratory conditions (9 trials, Iran)
- Form
- Zataria multiflora preparations
- Dose
- Varied by trial
- Duration
- Varied by trial
- Source
- Reference 5 · PubMed 40011883 (opens PubMed)
CGrade CColitis symptoms and antioxidant markersUlcerative colitisFewer bowel symptoms vs placeboRCT
n 92 · 2025
Improved Bowel frequency, urgency of defecation, general well-being and final P-SCCAI scores improved vs placebo (all p < 0.001). TAC, SOD and thiol levels rose; malondialdehyde did not fall significantly (p = 0.06).
- Design
- RCT, n = 92, 2025
- Population
- Adults with mild-to-moderate ulcerative colitis (multicentre, Iran)
- Form
- Zataria multiflora extract vs placebo
- Dose
- 6 mg/kg/day
- Duration
- 2 months
- Source
- Reference 1 · PubMed 40319670 (opens PubMed)
CGrade CDisease activity, digestive symptoms and inflammation markersUlcerative colitisSymptoms better; Mayo score unchangedRCT
n 92 · 2025
Mixed GSRS digestive-symptom score improved (p < 0.001) and CRP, IL-17 and interferon-gamma fell, but the partial Mayo disease-activity score did not change significantly (p = 0.24), nor did ESR.
- Design
- RCT, n = 92, 2025
- Population
- Adults with ulcerative colitis (multicentre, Iran)
- Form
- Zataria multiflora hydroalcoholic extract vs placebo
- Dose
- 6 mg/kg/day
- Duration
- 2 months
- Source
- Reference 2 · PubMed 39987994 (opens PubMed)
CGrade CInsulin resistance and liver markers in fatty liver diseaseFatty liverLower insulin resistance; liver grade unchangedRCT
n 85 · 2018
Mixed Serum insulin, insulin resistance (HOMA change -0.80 vs +0.06) and systolic and diastolic blood pressure fell vs placebo; ALT, hs-CRP, TNF-alpha, lipids and ultrasound fatty-liver grade did not differ.
- Design
- RCT, n = 85, 2018
- Population
- Adults with non-alcoholic fatty liver disease (Shiraz, Iran)
- Form
- Zataria multiflora powder vs placebo
- Dose
- 700 mg twice daily (1,400 mg/day)
- Duration
- 12 weeks
- Source
- Reference 9 · PubMed 30477827 (opens PubMed)
DGrade DLung function, symptoms and inhaler use in COPDCOPDBetter FEV1, less inhaler useRCT
n 45 · 2024
Improved FEV1 improved with the extract (p < 0.05 to p < 0.01). Respiratory symptoms improved and white cell counts fell compared with baseline, and inhaled bronchodilator use fell by the end of the study in both extract groups.
- Design
- RCT, n = 45, 2024
- Population
- Adults with COPD (Mashhad, Iran)
- Form
- Zataria multiflora extract vs placebo
- Dose
- 3 or 6 mg/kg/day
- Duration
- 1-2 months
- Source
- Reference 3 · PubMed 38373666 (opens PubMed)
DGrade DAsthma symptoms and lung functionAsthmaBetter symptoms vs baselineRCT
n 36 · 2020
Improved Symptoms and lung-function tests improved at 1 and 2 months in both extract groups compared with their own baseline (p < 0.05 to p < 0.001); oxidative-stress and cytokine markers also improved vs baseline.
- Design
- RCT, n = 36, 2020
- Population
- Adults with asthma (Mashhad, Iran)
- Form
- Zataria multiflora extract vs placebo
- Dose
- 5 or 10 mg/kg/day in three daily doses
- Duration
- 2 months
- Source
- Reference 4 · PubMed 32585581 (opens PubMed)
DGrade DBlood inflammation markers in asthmaAsthmaLower CRP vs baselineRCT
n 36 · 2022
Improved hs-CRP, total white cells, monocytes and eosinophils fell and lung-function values rose in both extract groups vs baseline. Haemoglobin and haematocrit fell with 10 mg/kg/day and MCV fell with both doses.
- Design
- RCT, n = 36, 2022
- Population
- Adults with asthma (Mashhad, Iran)
- Form
- Zataria multiflora leaf and stem extract vs placebo
- Dose
- 5 or 10 mg/kg/day
- Duration
- 2 months
- Source
- Reference 7 · PubMed 34863879 (opens PubMed)
Human studies not graded here
2 notes- Irritable bowel syndrome (combination product)
- A 4-week Iranian trial compared a capsule of Shirazi thyme plus ajwain (Trachyspermum copticum) with placebo and mebeverine and reported less pain, bloating and reflux with the herbal mix. Because the capsule combined two herbs and the abstract does not give the number analysed, it is not graded for Shirazi thyme alone.11
- Overweight (with oxymel)
- A 12-week trial gave 0.75 g or 1.5 g of Shirazi thyme in 10 mL of oxymel twice a day, against oxymel alone. Waist circumference fell in all three groups, including the oxymel-only control, BMI did not change, and lipids, liver enzymes and creatinine were unaffected, so no effect can be credited to the herb itself.12
What the numbers add up to
Each point is worked out from the data and the sources numbered on this page, with the arithmetic shown under it. It adds no new data and is not medical advice.
Studied doses
Doses used in research, shown against the official limits. They describe the studies, not a recommendation for you.
Studied doses in research, not advice. These are amounts used in research, not personal advice. Your clinician or pharmacist can say what fits you.
Doses studied in human trials
Interactions and safety
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Interactions
0 agentsNone found in our sources.
Check with what you take
Kept on this device onlyAdd what you take. We list every interaction our evidence profiles cite between Shirazi thyme and your picks, and between your picks.
- Loading names…
Add a supplement or medicine you take to check it against Shirazi thyme.
Starting from one medicine? The interaction checker rates how serious each pair is, on a curated list of 19 entries for 11 medicines. This cabinet has no severity rating: it lists every interaction row our supplement pages cite.
Who should be careful
4 groups- People on asthma or COPD medicines
- In the COPD trial the extract was used alongside usual inhaled medicines; no trial tested it as a replacement for inhalers or other prescribed medicines.34
- People with anaemia
- In the asthma trial, haemoglobin and haematocrit fell with 10 mg/kg/day; the clinical meaning is unclear.7
- People on medicines
- We found no published drug-interaction studies or case reports for Shirazi thyme in PubMed, and the trials did not test interactions, so effects with blood thinners, diabetes drugs or sedatives are unknown. In the fatty-liver trial, insulin resistance and blood pressure fell, which matters for people on diabetes or blood-pressure medicines.1349
- Pregnancy and breastfeeding
- NCCIH notes that many dietary supplements have not been tested in pregnant women or nursing mothers, and no Shirazi thyme trial reported results in them.8
How to read the label
What to check on the Supplement Facts panel.
How to read the label
3 checksCheck the botanical name
Shirazi thyme is Zataria multiflora, a different plant from common thyme (Thymus vulgaris). The trials on this page tested Zataria only.2
Extract or powder
Frequently asked questions
Short answers to common questions; the numbers link to the sources below.
Common questions
8 answersDoes Shirazi thyme help ulcerative colitis?
Does it help asthma or COPD?
Is it safe?
Does Shirazi thyme help fatty liver or blood sugar?
In one 85-patient trial, 1,400 mg of powder a day for 12 weeks lowered insulin resistance and blood pressure versus placebo, but the liver enzyme ALT and ultrasound liver fat did not differ from placebo (grade C).9
How much was used in studies?
Does Shirazi thyme interact with medicines?
We found no published interaction studies or case reports. Because one trial saw lower insulin resistance and blood pressure, people on diabetes or blood-pressure medicines have reason to be careful.9
Is Shirazi thyme safe in pregnancy or breastfeeding?
No trial has tested it in pregnant or breastfeeding women. NCCIH notes that many supplements have not been tested in these groups.8
What is Shirazi thyme?
Zataria multiflora, a thyme-like aromatic herb used in Persian medicine for digestive and inflammatory complaints. It is a different plant from common garden thyme.2
Sources
12 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.
Sources cited on this page
12 sources- 1The impact of Zataria multiflora on oxidative stress biomarkers and ulcerative colitis symptoms: A multicenter, triple-blind, placebo-controlled clinical trial.RCT Explore (NY), 2025 · PMID 40319670
- 2Zatariamultiflora hydroalcoholic extract: A triple-blind randomized controlled trial on immune genes, inflammation, and ulcerative colitis symptoms.RCT J Ethnopharmacol, 2025 · PMID 39987994
- 3Zataria multiflora affects pulmonary function tests, respiratory symptoms, bronchodilator drugs use and hematological parameters in chronic obstructive pulmonary disease patients: A randomized doubled-blind clinical trial.RCT J Ethnopharmacol, 2024 · PMID 38373666
- 4Zataria multiflora affects clinical symptoms, oxidative stress and cytokines in asthmatic patient: A randomized, double blind, placebo-controlled, phase II clinical trial.RCT Cytokine, 2020 · PMID 32585581
- 5The effect of Zataria multiflora on respiratory symptoms, pulmonary functions, and oxidative stress parameters: a systematic review and meta-analysis.Meta-analysis BMC Complement Med Ther, 2025 · PMID 40011883
- 6Effect of Zataria multiflora supplementation on pro- or anti-inflammatory markers: a systematic review and meta-analysis of randomized placebo-controlled trials.Meta-analysis Inflammopharmacology, 2025 · PMID 39992592
- 7Zataria multiflora extract influenced asthmatic patients by improving respiratory symptoms, pulmonary function tests and lung inflammation.RCT J Ethnopharmacol, 2022 · PMID 34863879
- 8Using Dietary Supplements WiselyFact sheet National Center for Complementary and Integrative Health (NCCIH), 2019 · nccih.nih.gov
- 9The effects of Zataria multiflora Boiss. (Shirazi thyme) on nonalcoholic fatty liver disease and insulin resistance: A randomized double-blind placebo-controlled clinical trial.RCT Complement Ther Med, 2018 · PMID 30477827
- 10A Randomized, Doubled-Blind Clinical Trial on the Effect of Zataria multiflora on Clinical Symptoms, Oxidative Stress, and C-Reactive Protein in COPD Patients.RCT J Clin Pharmacol, 2020 · PMID 32202330
- 11Clinical evaluation of the effect of Zataria multiflora Boiss and Trachyspermum copticum (L.) on the patients with irritable bowel syndrome.RCT Explore (NY), 2022 · PMID 34969608
- 12Effects of Zataria oxymel on obesity, insulin resistance and lipid profile: A randomized, controlled, triple-blind trial.RCT J Integr Med, 2020 · PMID 32651141
What changed
Every dated change to this page: what changed, who made it and why.
Change log
3 entries| Date | Change | Who and why |
|---|---|---|
| summary, key facts, evidence, forms, studied doses, other human studies, who should be careful, label guide, FAQ | Added a fatty-liver trial (PMID 30477827) as a graded row and a powder form; noted a 2020 COPD paper from the same group (PMID 32202330); added ungraded notes on a bowel-syndrome trial of a two-herb capsule (PMID 34969608) and a weight trial with oxymel (PMID 32651141). Searched PubMed and LactMed for interactions: none published, noted on the page. New label guide and three FAQs. Fact-checked against the sources; corrected: the fatty-liver trial reported ALT (not liver enzymes in general) as not differing from placebo, the interaction answer now says we found no reports and that one trial (not several) lowered insulin resistance, and the label guide no longer calls every trial extract hydroalcoholic. | Writer: Kymata Health EditorialTrigger: A–Z page audit |
| who should avoid | Pregnancy and breastfeeding caution re-sourced to NCCIH (agency source) instead of trial reports | Writer: Kymata Health EditorialTrigger: adversarial review |
| all | Initial editorial evidence review | Writer: Kymata Health EditorialTrigger: new page |
Supplement & Nutrient Encyclopedia. Educational information only; it is not medical advice and does not replace a clinician. Dietary supplements are not intended to diagnose, treat, cure or prevent any disease. Statements about supplements have not been evaluated by the FDA.