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Dietary supplement

Thuja Ingredients & Drug Interactions

by Herbalist & Alchemist

Thuja label
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Liquid 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 Thuja 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

Thuja is a dietary supplement by Herbalist & Alchemist with 1 active ingredient. Its ingredients are commonly taken for warts and skin growths, respiratory and immune support, cold and upper respiratory symptoms.Based on those ingredients, 576 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are fresh Thuja leaf extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Thuja by Herbalist & Alchemist

Ask about any prescription or over-the-counter medication and we check it for interactions with Thuja by Herbalist & Alchemist — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Thuja by Herbalist & Alchemist

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.

This product contains one active ingredient: fresh Thuja leaf extract. Thuja is a plant extract traditionally used in herbal preparations, though its effectiveness for common cold remains unproven in our data.

The liquid also includes inactive ingredients — ethyl alcohol, distilled water, and vegetable glycerin — which serve as the base for the extract.

Does it work?

Not established
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 established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use — see Thuja's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: supports healthy immune function.
  • We looked for evidence on: Common cold, upper respiratory infection, immune support, respiratory health.
  • The closest evidence on file: Thuja is rated "Insufficient Reliable Evidence To Rate" for Common cold (Natural Medicines).

The evidence we hold does not establish that Thuja is effective for the common cold. The data shows insufficient reliable evidence to rate its use for this condition, which means studies are either missing, too small, or inconclusive.

The evidence, ingredient by ingredient Thuja

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.

Thuja carries real safety concerns. The plant contains thujone, a compound that can be toxic in large doses.

Documented adverse effects from high doses include headache, nervous agitation, seizures, gastric irritation, vomiting, abdominal pain, diarrhea, liver damage, kidney damage, and in severe cases death. Contact dermatitis (itchy rash on the hands) has also been reported from handling thuja plants.

Because of its traditional use to stimulate the uterus and menstruation, Thuja is rated likely unsafe in pregnancy. It's also rated likely unsafe while breastfeeding, so safety data isn't established in that setting.

Side effects, ingredient by ingredient Thuja

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 — Thuja.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: seizure medications; immunosuppressants / transplant drugs.
  • For scale: 576 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.

Check with us before using Thuja if you take seizure threshold lowering drugs (Moderate severity) — especially anesthetics — anticonvulsants (seizure medications, Moderate severity), or immunosuppressants (Moderate severity). These are the main medication types where interactions are documented.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.

Thuja is not for you if you take seizure or immunosuppressant medications, or if you're pregnant or breastfeeding. The evidence for common cold effectiveness isn't there in our data.

If you have a seizure disorder, immune condition, or are considering this while pregnant or nursing, talk with your pharmacist or doctor before starting.

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 Thuja, straight from the product label.

Brand Herbalist & Alchemist
Barcode (UPC) 667056127466
Net contents 2 fl. Oz.; 60 mL
Market status On market
Date entered into DSLD Mar 23, 2018
DSLD ID 174807
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Kosher
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 Thuja by Herbalist & Alchemist, 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:
0.5 mL
Maximum serving Sizes:
0.75 mL
Servings per container
80
UPC/BARCODE
667056127466
IngredientAmount% DV
fresh Thuja leaf extract0.75 mL--

Other ingredients: Ethyl Alcohol, distilled Water, Vegetable Glycerin

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.
Formula

Thuja occidentalis

OK

General Statements

Supports healthy immune function

Botanical preparation ratio 1:3.62

FDA Statement of Identity

Herbal Supplement

Suggested/Recommended/Usage/Directions

Suggested Use: 10-15 drops (0.5-0.75 mL) in juice or water. Take 3 times per day. Shake well before using.

Precautions

Contraindications: Do not use during pregnancy unless otherwise directed by a qualified expert.

Not for long-term use. Do not exceed recommended dose.

Keep out of children's reach

FDA Disclaimer Statement

This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure or prevent any disease.

General

NO. TJA-2 1727MO

Seals/Symbols

OK

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

See for yourself

Thuja by Herbalist & Alchemist label

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

Thuja 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 Thuja by Herbalist & Alchemist

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

Serving size0.5 mL Dosage formLiquid Servings per container80 Amounts shown are per serving.

Fresh Thuja leaf extract

Interacts with
576 drugs
0.75 mL per serving

Thuja, also called northern white cedar or arborvitae, is a tree whose leaf and oil have a long history in folk and homeopathic medicine, especially f...

Fresh Thuja leaf extract monograph & interactions

Other (inactive) ingredients: Ethyl Alcohol, Distilled Water, Vegetable Glycerin. These complete the product’s ingredient list but are not active constituents.

Interaction report

Thuja by Herbalist & Alchemist Drug Interactions

Want to check YOUR meds against Thuja?

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
576Drugs
576 Moderate

Ingredients driving the most interactions

fresh Thuja leaf extract 576

Individual Drug Interactions

The ingredients in Thuja interact with 576 drugs. Click any drug to see the details.

1 of the 1 ingredient in Thuja interact with drugs. Each result below shows which ingredient is responsible. fresh Thuja leaf extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Thuja 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.

fresh Thuja leaf extract3 drug types · 576 drugs

Anticonvulsants

Thuja products can contain thujone, which might lower the seizure threshold. Theoretically, this could decrease the effectiveness of anticonvulsants drugs.

Likelihood Possible Evidence D
Immunosuppressants

Thuja might stimulate immune function. Theoretically, taking thuja might decrease the effects of immunosuppressive therapy. Immunosuppressant drugs include azathioprine (Imuran), basiliximab (Simulect), cyclosporine (Neoral, Sandimmune), daclizumab (Zenapax), muromonab-CD3 (OKT3, Orthoclone OKT3), mycophenolate (CellCept), tacrolimus (FK506, Prograf), sirolimus (Rapamune), prednisone (Deltasone, Orasone), and other corticosteroids (glucocorticoids).

Likelihood Possible Evidence D
Seizure Threshold Lowering Drugs

Thuja products can contains significant amounts of thujone, a neurotoxin. Theoretically, patients taking drugs that lower the seizure threshold might be at greater risk of seizure if they also take thuja. Advise patients taking these drugs to avoid thuja products. Some drugs that lower the seizure threshold include anesthetics (propofol, others), antiarrhythmics (mexiletine), antibiotics (amphotericin, penicillin, cephalosporins, imipenem), antidepressants (bupropion, others), antihistamines (cyproheptadine, others), immunosuppressants (cyclosporine), narcotics (fentanyl, others), stimulants (methylphenidate), theophylline, and others.

Likelihood Possible Evidence D
fresh Thuja leaf extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Thuja, from the product label.

Herbalist & Alchemist

See all Herbalist & Alchemist products
Name
Herbalist & Alchemist, Inc.
City
Washington
State
NJ
ZipCode
07882
Phone Number
800-611-8235
Web Address
www.herbalist-alchemist.com
Pharmacist Counseling Corner

Thuja by Herbalist & Alchemist: Common Questions

Does Thuja by Herbalist & Alchemist interact with any medications?
Yes. Based on its ingredients, Thuja has a known interaction with 576 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Thuja 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 Thuja safe to take while pregnant?
No. Thuja is rated likely unsafe in pregnancy because it has traditionally been used to stimulate the uterus and menstruation. If you're pregnant or planning to become pregnant, avoid this product and talk with your pharmacist or doctor.
Can I breastfeed while taking Thuja?
No. Safety isn't established for breastfeeding, so Thuja is rated likely unsafe in that setting. Talk with your pharmacist or doctor about alternatives if you're nursing.
Does Thuja actually work for colds?
The evidence we hold is insufficient to say whether Thuja works for the common cold. Studies are either missing or inconclusive on this use.
What are the side effects of Thuja?
At high doses, Thuja can cause headache, nervous agitation, seizures, stomach upset, vomiting, abdominal pain, and diarrhea. Serious cases have involved liver damage, kidney damage, and even death. Contact dermatitis (an itchy rash) can develop from touching thuja plants. The culprit is thujone, a toxic compound in the plant.
Why does the product label mention seizure risk?
Thuja contains thujone, which can lower your seizure threshold — meaning it makes seizures more likely. If you take seizure medications or anesthetics, this interaction could be serious. That's why we advise against using Thuja if you're on those drugs.

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

Not sure if Thuja is safe with your meds?

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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.

Thuja label
Go deeper

The Full Monographs Behind Thuja’s Ingredients

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

Herb & supplement monograph

Thuja

Interacts with 576 drugs

Thuja, also called northern white cedar or arborvitae, is a tree whose leaf and oil have a long history in folk and homeopathic medicine, especially for warts and immune support. Solid human...

Read the full Thuja monograph →
Sources

Sources & How We Checked

Thuja'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 10 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.

Thuja 10 references
  1. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  2. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  3. Millet Y, Jouglard J, Steinmetz MD, et al. Toxicity of some essential plant oils. Clinical and experimental study. Clin Toxicol 1981;18:1485-98. PubMed
  4. Gohla SH, Haubeck HD, Neth RD. Mitogenic activity of high molecular polysaccharide fractions isolated from the Cupressaceae Thuja occidentale L. I. Macrophage-dependent induction of CD-4-positive T-helper (Th+) lymphocytes. Leukemia 1988;2:528-33.
  5. Fetrow CW, Avila JR. Professional's Handbook of Complementary & Alternative Medicines. 1st ed. Springhouse, PA: Springhouse Corp., 1999.
  6. Henneicke-von Zepelin H, Hentschel C, Schnitker J, et al. Efficacy and safety of a fixed combination phytomedicine in the treatment of the common cold (acute viral respiratory tract infection): results of a randomised, double blind, placebo-controlled, m
  7. Naser, B., Bodinet, C., Tegtmeier, M., and Lindequist, U. Thuja occidentalis (Arbor vitae): A Review of its Pharmaceutical, Pharmacological and Clinical Properties. Evid.Based Complement Alternat.Med 2005;2(1):69-78.
  8. Patel R, Alavi F, Ortega S, Matela A. Herb-Induced Liver Injury by Cimicifuga racemosa and Thuja occidentalis Herbal Medications for Fertility. Case Rep Gastrointest Med 2021;2021:8858310. PubMed
  9. Ambooken B, Thomas M, Jisha KT. Papillary Eccrine Adenoma in a 5-year-old Girl Altered by Application of Thuja Ointment. J Cutan Aesthet Surg 2020;13(4):370-371. PubMed
  10. Badaoui A, Fougerousse AC. Contact dermatitis to linalool and limonene: Unusual sources of exposure. Ann Dermatol Venereol 2023;150(2):167-168. PubMed

See these in context on the Thuja 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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