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Dietary supplement

Thyme Leaf 500 mg Ingredients & Drug Interactions

by Swanson Premium Brand

Thyme Leaf 500 mg label
See full label image
Capsule Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Thyme Leaf 500 mg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Thyme Leaf 500 mg is a dietary supplement by Swanson Premium Brand with 1 active ingredient. Its ingredients are commonly taken for cough and respiratory congestion, sore throat, digestive upset.Based on those ingredients, 379 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Thyme. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Thyme Leaf 500 mg by Swanson Premium Brand

Ask about any prescription or over-the-counter medication and we check it for interactions with Thyme Leaf 500 mg by Swanson Premium Brand — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Thyme Leaf 500 mg by Swanson Premium Brand

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

Thyme Leaf 500 mg is a single-ingredient supplement — just thyme (also called common thyme), a culinary and medicinal herb from the mint family, dried and powdered into capsules at 500 mg per dose. The capsule itself is made of gelatin, a standard binding agent.

Does it work?

Couldn't assess
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not assessable

This is a single-ingredient Thyme product and its label doesn't state a use — see Thyme's own graded uses on its monograph.

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.

We don't have reliable evidence yet for thyme leaf at this dose for bronchitis, aging skin, alopecia areata (patchy hair loss), or the common cold. The data on file rates all these uses as insufficient evidence — which means the research either isn't there, isn't robust enough, or is mixed.

That doesn't mean thyme doesn't work for these things; it means we can't say from what we know.

The evidence, ingredient by ingredient Thyme

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Thyme as a food and in tea is generally well tolerated. At medicinal doses — like in this 500 mg capsule — safety data is limited, so use caution, especially if you're taking it long-term.

The concentrated essential oil is toxic if swallowed, but this capsule form is leaf powder, not pure oil. When taken by mouth, thyme has caused allergic reactions, diarrhea, dizziness, headache, heartburn, nausea, and vomiting in some people.

If you apply thyme topically (as an oil or extract), watch for contact dermatitis and skin irritation. Pregnancy and lactation are rated Likely Safe — but that applies to food amounts; talk with your doctor about medicinal doses if you're pregnant or nursing.

Side effects, ingredient by ingredient Thyme

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Thyme.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs.
  • For scale: 379 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before you take this, double-check with your pharmacist if you're on estrogen replacement therapy, blood thinners or antiplatelet drugs (like warfarin or aspirin), anticholinergic drugs (for overactive bladder or certain poisonings), or cholinergic drugs (for myasthenia gravis). All four are Moderate interactions based on lab evidence that hasn't yet shown up in people — but that's exactly why you want to confirm your specific medications.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Thyme leaf is generally well tolerated at food and medicinal doses, but if you take estrogen replacement therapy, blood thinners, or medications for bladder or nerve function, check your exact drugs with the tool below before starting. The safety data for long-term medicinal use is slim, so this is worth a quick pharmacist conversation, especially if you're pregnant or nursing.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Mar 23, 2018.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Thyme Leaf 500 mg, straight from the product label.

Brand Swanson Premium Brand
Barcode (UPC) 087614110622
Net contents 120 Capsule(s)
Market status On market
Date entered into DSLD Mar 23, 2018
DSLD ID 174896
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Adult (18 - 50 Years)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Thyme Leaf 500 mg by Swanson Premium Brand, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
UPC/BARCODE
087614110622
IngredientAmount% DV
Thyme500 mg--

Other ingredients: Gelatin, May contain one or both of the following

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
General Statements

Bringing wellness to the world since 1969

To reorder, call toll free 1-800-437-4148 or visit our website at www.swansonvitamins.com

FDA Statement of Identity

Herbal Supplement

Seals/Symbols

Guaranteed purity & potency

Precautions

Do not use if seal is broken.

Keep out of reach of children.

Storage

Store in a cool, dry place.

Suggested/Recommended/Usage/Directions

Suggested Use: As a dietary supplement, take one capsule one to two times per day with water.

General

SW1062 REV 0 04 27 17

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Thyme Leaf 500 mg by Swanson Premium Brand label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Thyme Leaf 500 mg label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Thyme Leaf 500 mg by Swanson Premium Brand

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Amounts shown are per serving.

Thyme

Interacts with
379 drugs
500 mg per serving

Thyme is a common kitchen herb that has long been used for coughs, sore throats, and digestive complaints. It is generally safe in the amounts found i...

Thyme monograph & interactions

Other (inactive) ingredients: Gelatin, May contain one or both of the following. These complete the product’s ingredient list but are not active constituents.

Interaction report

Thyme Leaf 500 mg by Swanson Premium Brand Drug Interactions

Want to check YOUR meds against Thyme Leaf 500 mg?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
379Drugs
379 Moderate

Ingredients driving the most interactions

Thyme 379

Individual Drug Interactions

The ingredients in Thyme Leaf 500 mg interact with 379 drugs. Click any drug to see the details.

1 of the 1 ingredient in Thyme Leaf 500 mg interact with drugs. Each result below shows which ingredient is responsible. Thyme

Each ingredient & the kinds of drugs it affects

For each ingredient in Thyme Leaf 500 mg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Thyme4 drug types · 379 drugs

Anticholinergic Drugs

Theoretically, concurrent use of anticholinergic drugs and thyme essential oil might reduce the effects of anticholinergic drugs.
In vitro evidence suggests that thyme essential oil and specific essential oil constituents like thymohydroquinone and carvacrol can inhibit acetylcholinesterase (AChE). However, this effect has not been observed in humans.

Likelihood Possible Evidence D
Anticoagulant/Antiplatelet Drugs

Theoretically, thyme leaf extract might have additive effects with anticoagulant or antiplatelet drugs.
In vitro and animal research suggests that thyme leaf extract has antiplatelet effects. However, this effect has not been observed in humans.

Likelihood Possible Evidence D
Cholinergic Drugs

Theoretically, concurrent use of cholinergic drugs and thyme essential oil might cause additive cholinergic effects.
In vitro evidence suggests that thyme essential oil and specific essential oil constituents like thymohydroquinone and carvacrol can inhibit acetylcholinesterase (AChE). However, this effect has not been observed in humans.

Likelihood Possible Evidence D
Estrogens

Theoretically, thyme might competitively inhibit the effects of estrogen replacement therapy.
In vitro research shows that thyme has estrogen receptor-binding activity and phytoestrogen content. However, this effect has not been observed in humans.

Likelihood Possible Evidence D
Thyme full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Thyme Leaf 500 mg, from the product label.

Swanson Premium Brand

See all Swanson Premium Brand products
Name
Swanson Health Products
City
Fargo
State
ND
ZipCode
58104
Phone Number
1-800-437-4148
Web Address
www.swansonvitamins.com
Pharmacist Counseling Corner

Thyme Leaf 500 mg by Swanson Premium Brand: Common Questions

Does Thyme Leaf 500 mg by Swanson Premium Brand interact with any medications?
Yes. Based on its ingredients, Thyme Leaf 500 mg has a known interaction with 379 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Thyme Leaf 500 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Will thyme leaf work for my cough or cold?
We don't have enough reliable evidence in our data to say whether thyme leaf is effective for colds or bronchitis. It's been used traditionally, but the research isn't solid enough yet to rate it.
Is it safe to take thyme if I'm pregnant or breastfeeding?
Pregnancy and lactation are rated Likely Safe for thyme at food amounts — think of it like the herb in cooking. But we don't have solid safety data for medicinal doses, so talk with your doctor about whether this 500 mg capsule is right for you during pregnancy or nursing.
What side effects might I get?
Most people tolerate thyme well. Orally, some folks report allergic reactions, diarrhea, dizziness, headache, heartburn, nausea, or vomiting. If you're using it topically, watch for skin irritation or contact dermatitis.
Is the thyme in this capsule the same as the herb I cook with?
Yes — it's the same plant, just dried and powdered into a concentrated 500 mg capsule. Because it's a medicinal dose rather than a food amount, safety data is more limited, so use it with a bit more caution.
Can I take this with my estrogen or hormone replacement therapy?
Lab work shows thyme might theoretically interfere with estrogen medications, but we haven't seen this happen in people yet. This is definitely one to verify with your pharmacist before you start, especially since you need your hormone dose to be reliable.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Thyme Leaf 500 mg label
Go deeper

The Full Monographs Behind Thyme Leaf 500 mg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Thyme

Interacts with 379 drugs

Thyme is a common kitchen herb that has long been used for coughs, sore throats, and digestive complaints. It is generally safe in the amounts found in food, and some cough products that com...

Read the full Thyme monograph →
Sources

Sources & How We Checked

Thyme Leaf 500 mg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 18 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Thyme 18 references
  1. Zava DT, Dollbaum CM, Blen M. Estrogen and progestin bioactivity of foods, herbs, and spices. Proc Soc Exp Biol Med 1998;217:369-78. PubMed
  2. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  3. Okazaki K, Kawazoe K, Takaishi Y. Human platelet aggregation inhibitors from thyme (Thymus vulgaris L.). Phytother Res 2002;16:398-9. .
  4. Spiewak R, Skorska C, Dutkiewicz J. Occupational airborne contact dermatitis caused by thyme dust. Contact Dermatitis 2001;44:235-9. . PubMed
  5. Ernst E, Marz R, Sieder C. A controlled multi-centre study of herbal versus synthetic secretolytic drugs for acute bronchitis. Phytomedicine 1997;4:287-93. PubMed
  6. Yamamoto J, Yamada K, Naemura A, et al. Testing various herbs for antithrombotic effect. Nutrition 2005;21(5):580-7. PubMed
  7. Tognolini, M., Barocelli, E., Ballabeni, V., Bruni, R., Bianchi, A., Chiavarini, M., and Impicciatore, M. Comparative screening of plant essential oils: phenylpropanoid moiety as basic core for antiplatelet activity. Life Sci. 2-23-2006;78(13):1419-1432. PubMed
  8. Mackiewicz, B., Skorska, C., Dutkiewicz, J., Michnar, M., Milanowski, J., Prazmo, Z., Krysinska-Traczyk, E., and Cisak, E. Allergic alveolitis due to herb dust exposure. Ann Agric Environ Med 1999;6(2):167-170.
  9. Martinez-Gonzalez, M. C., Goday Bujan, J. J., Martinez, Gomez W., and Fonseca, Capdevila E. Concomitant allergic contact dermatitis due to Rosmarinus officinalis (rosemary) and Thymus vulgaris (thyme). Contact Dermatitis 2007;56(1):49-50.
  10. Jukic, M., Politeo, O., Maksimovic, M., Milos, M., and Milos, M. In vitro acetylcholinesterase inhibitory properties of thymol, carvacrol and their derivatives thymoquinone and thymohydroquinone. Phytother.Res 2007;21(3):259-261.
  11. Marzian, O. [Treatment of acute bronchitis in children and adolescents. Non-interventional postmarketing surveillance study confirms the benefit and safety of a syrup made of extracts from thyme and ivy leaves]. MMW.Fortschr.Med 6-28-2007;149(27-28 Suppl
  12. Cuzzolin, L. and Benoni, G. Attitudes and knowledge toward natural products safety in the pharmacy setting: an Italian study. Phytother.Res 2009;23(7):1018-1023. PubMed
  13. Berova, N., Stransky, L., and Krasteva, M. Studies on contact dermatitis in stomatological staff. Dermatol.Monatsschr. 1990;176(1):15-18.
  14. Smeenk, G., Kerckhoffs, H. P., and Schreurs, P. H. Contact allergy to a reaction product in Hirudoid cream: an example of compound allergy. Br.J Dermatol. 1987;116(2):223-231.
  15. Le Roy, R., Grosshans, E., and Foussereau, J. [Investigation of contact allergies in 100 cases of ulcus cruris (author's transl)]. Derm.Beruf.Umwelt. 1981;29(6):168-170.
  16. Lorenzi, S., Placucci, F., Vincenzi, C., Bardazzi, F., and Tosti, A. Allergic contact dermatitis due to thymol. Contact Dermatitis 1995;33(6):439-440. PubMed
  17. Bahadoran P, Rokni FK, Fahami F. Investigating the therapeutic effect of vaginal cream containing garlic and thyme compared to clotrimazole cream for the treatment of mycotic vaginitis. Iran J Nurs Midwifery Res 2010;15(Suppl 1):343-9.
  18. Erol S, Aydin B, Dilli D, Okumus N, Zenciroglu A, Gündüz M. An interesting newborn case of fructose 1-6 diphosphatase deficiency triggered after thyme juice ingestion. Clin Lab. 2014;60(1):151-3. PubMed

See these in context on the Thyme monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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