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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 Sep 17, 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.

This product contains one active ingredient: 500 mg of thyme leaf per capsule. Thyme is an herb traditionally used in cooking and herbal preparations.

The capsule itself is made from gelatin.

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.

The evidence we hold doesn't establish whether thyme leaf works for bronchitis, aging skin, alopecia areata (patchy hair loss), or the common cold. All the ratings in our data show insufficient reliable evidence, meaning studies either don't exist, are too small, or haven't been strong enough to draw firm conclusions.

If you're considering this for one of those uses, talk it over with your doctor or pharmacist to weigh what's known against other options.

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 is generally well tolerated when eaten as food and seems tolerable when used medicinally, with most side effects being mild—allergic reactions, diarrhea, dizziness, headache, heartburn, nausea, or vomiting. Topically, it can cause contact dermatitis and skin irritation in some people.

The main caution is that concentrated thyme essential oil can be toxic if swallowed, and medicinal or essential-oil amounts haven't been studied enough in pregnancy and breastfeeding to know they're safe—so food amounts are likely fine, but talk with your doctor before taking a medicinal dose 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 taking this product, check with your doctor or pharmacist if you take estrogens (including birth control or hormone replacement), blood thinners or antiplatelet drugs like warfarin or aspirin, anticholinergic drugs (like those for overactive bladder), or cholinergic drugs. All four categories show moderate-severity interaction potential with thyme.

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 may be worth trying if you're looking for an herbal option and you're not taking estrogens, blood thinners, or drugs that affect acetylcholine pathways—but check your medications first. If you're pregnant, nursing, or using medicinal doses, run it by your doctor or pharmacist before you start.

The evidence for what it actually does isn't solid yet.

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.
Is thyme safe if I'm pregnant or breastfeeding?
Our data rates thyme as likely safe in pregnancy and lactation, but that's based on food amounts. If you're thinking about medicinal doses, there isn't enough safety data to be sure, so talk with your doctor or pharmacist for personalized advice.
What are the side effects I might notice?
Thyme is generally well tolerated, but some people report allergic reactions, diarrhea, dizziness, headache, heartburn, nausea, or vomiting when taken by mouth. If you apply thyme to your skin, watch for contact dermatitis or irritation.
Does thyme actually work for colds or cough?
The evidence we hold for thyme and the common cold, or for bronchitis, isn't strong enough to say. We rate both as having insufficient reliable evidence, so we can't tell you it will help based on the data we have.
Why are there so many medication interactions listed?
The 379 medications span four drug categories—estrogens, blood thinners, anticholinergics, and cholinergics—because thyme has multiple active compounds. Many drugs fall into each category, so the total is large, but most interactions are theoretical and haven't been seen in actual people.
Is this the same as thyme essential oil?
No—this is thyme leaf in capsule form, which is different from concentrated essential oil. Essential oil is much more potent and can be toxic if swallowed, so never use it as a substitute for this product without medical guidance.
Can I use this if I take birth control?
Thyme shows estrogen-binding activity in lab studies, which might theoretically reduce birth control effectiveness, but this hasn't been confirmed in humans. Because the risk isn't certain, check with your doctor or pharmacist before combining them.

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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