Oak Moss + Erlotinib
Erlotinib brand name: Tarceva.
We found no known interaction between Oak Moss and Erlotinib in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the label for Erlotinib states a food rule worth keeping to, and the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.
Oak Moss and Erlotinib
We checked these two against our interaction database. Here is what we found.
No Known Interaction Found
We did not find a documented interaction between Erlotinib and Oak Moss in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.
Worth understanding: our licensed dataset holds no drug-interaction record for Oak Moss at all — not against Erlotinib, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.
If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.
Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.
Oak Moss safety at a glance
Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
Oak Moss in Pregnancy & Breastfeeding
When used orally. The constituent thujone shows evidence of uterine stimulant activity.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center
Some Erlotinib Products Have a Food Rule — Oak Moss Should Not Break It
At least one FDA label for a product containing Erlotinib says to take it on an empty stomach. Most supplements — Oak Moss included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Erlotinib on its own and move Oak Moss to a meal later in the day.
This may not be true of your version. Food instructions belong to the product, not the ingredient: two Erlotinib products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.
Recommended Dose – NSCLC The recommended daily dose of erlotinib tablets for NSCLC is 150 mg taken on an empty stomach, i.e., at least one hour before or two hours after the ingestion of food.
From the Dosage and Administration section of the FDA label we read for Erlotinib — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›
A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.
See Every Supplement That Interacts With Erlotinib
This page covers Oak Moss only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Erlotinib page lists 18 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Activated Charcoal (major), Bilberry (moderate), Coffee Charcoal (moderate), European Mandrake (moderate) and Glucomannan (moderate).
By severity: 1 major · 8 moderate · 9 minor.
From our pharmacist’s overview on the Erlotinib page
“Activated charcoal is the entry I would flag first for anyone taking erlotinib (Tarceva), an oral targeted therapy for certain lung cancers. Charcoal can adsorb the drug in the gut and cut how much reaches the bloodstream, and with a cancer pill, less absorbed means less cancer fought.”
Reviewed by 2 · Jul 18, 2026
Where Oak Moss and Erlotinib Sit Against Everything Else
Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.
#1,268 of 1,452 supplements looked up here in the last 7 days
#1,736 of 2,830 medications looked up here in the last 7 days
Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.
Where does our data come from?
- Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
- Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Oak Moss reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 27, 2026. The Oak Moss and Erlotinib records this page draws on were last updated July 10, 2026.
- What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
About Oak Moss
What is Oak Moss?
- Perfume base note and scent fixative
- Aromatherapy and fragrance
- Traditional antimicrobial use
- Soaps and cosmetics fragrance
Oak moss is a lichen that grows on oak and other trees and is best known as a perfume ingredient prized for its earthy, woody scent. There is very little human evidence to support taking it for any health condition, and it is a well-known skin allergen, so it is mainly used externally in fragrances rather than as a dietary supplement.
Evernia prunastri · Parmeliaceae · Whole lichen (thallus) and its extract/absolute · Essential oil, absolute, extract, fragrance ingredient; occasionally tinctures
An interaction check asks whether these two react with each other — it does not ask whether Oak Moss is a good idea for someone in your situation. Here is what our Oak Moss record says about it on its own.
Oak Moss: dosing
There is no established safe or effective oral dose for oak moss. It is not a standard dietary supplement, and reliable dosing information from human studies does not exist.If you come across an oak moss product, follow the directions on the label and do not exceed them. Given the lack of safety data, oral use is generally not recommended.
From our Oak Moss monograph — the full record covers uses, side effects and every documented interaction.
About Erlotinib
What Is Erlotinib Used For?
Brand name: Tarceva
Erlotinib tablets are used to treat metastatic non-small cell lung cancer (NSCLC) in patients whose tumors carry specific gene changes — EGFR exon 19 deletions or exon 21 (L858R) mutations — confirmed by an FDA-approved test. It can be used as a first-line treatment, as maintenance therapy, or after at least one prior chemotherapy has stopped working.
Erlotinib tablets are also used for the first-line treatment of locally advanced, unresectable, or metastatic pancreatic cancer — but only in combination with another chemotherapy drug called gemcitabine. Erlotinib is not recommended alongside platinum-based chemotherapy regimens.
Most-Reported Side Effects for Erlotinib
From FAERS, the FDA’s public side-effect reporting system (12,441 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.
Other Drugs & Oak Moss
Browse every other medication we’ve checked against Oak Moss — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
No interaction 2,829 drugs checked — show the list
We also checked Oak Moss against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Amlodipine ›
- Levothyroxine ›
- Methylphenidate ›
- Warfarin ›
- Abemaciclib ›
- Ivermectin ›
- Testosterone ›
- Sertraline ›
- Acetaminophen ›
- Losartan Potassium ›
- Aspirin ›
- Rosuvastatin ›
- Metoprolol ›
- Escitalopram ›
- Clopidogrel ›
- Rivaroxaban ›
- Atorvastatin ›
- Methamphetamine ›
- Isotretinoin ›
- Tirzepatide ›
- Warfarin Sodium ›
- Docusate ›
- Ibuprofen ›
- Sumatriptan ›
- Amlodipine Besylate ›
- Valacyclovir ›
- Hydroxyurea ›
- Tadalafil ›
- Prednisone ›
- Metformin ›
- Semaglutide ›
- Amitriptyline ›
- Lisdexamfetamine ›
- Propranolol ›
- Amphetamine ›
- Methotrexate ›
- Amoxicillin ›
- Lisinopril ›
- Levothyroxine, Liothyronine ›
- Bupropion ›
- Fluoxetine ›
- Bendamustine ›
- Doxycycline ›
- Azithromycin ›
- Pregabalin ›
- Lamotrigine ›
- Gabapentin ›
- Dextroamphetamine ›
- Acyclovir ›
- Naproxen ›
- Quetiapine ›
- Clonazepam ›
- Buspirone ›
- Omeprazole ›
- Duloxetine ›
- Letrozole ›
- Acetaminophen, Codeine ›
- Acetaminophen, Aspirin, Caffeine ›
- Citalopram ›
Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Oak Moss list.
Oak Moss References
The 16 references that drive our Oak Moss monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.
- McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
- Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
- Dahlquist I, Fregert S. Contact allergy to atranorin in lichens and perfumes. Contact Dermatitis 1980;6:111-9. PubMed
- Goncalo S. Contact sensitivity to lichens and compositae in Frullania dermatitis. Contact Dermatitis 1987;16:84-6. PubMed
- Goncalo S, Cabral F, Goncalo M. Contact sensitivity to oak moss. Contact Dermatitis 1988;19:355-7. PubMed
- Thune P, Solberg Y, McFadden N, et al. Perfume allergy due to oak moss and other lichens. Contact Dermatitis 1982;8:396-400. PubMed
- Favreau JT, Ryu Ml, Braunstein G, et al. Severe hepatotoxicity associated with the dietary supplement LipoKinetix. Ann Intern Med 2002;136:590-5. PubMed
- Ingolfsdottir K. Usnic acid. Phytochemistry 2002;61:729-36.
- Mitchell, J. C. Allergy to lichens. Allergic contact dermatitis from usnic acid produced by lichenized fungi. Arch Dermatol 1965;92(2):142-146.
- Durazo, F. A., Lassman, C., Han, S. H., Saab, S., Lee, N. P., Kawano, M., Saggi, B., Gordon, S., Farmer, D. G., Yersiz, H., Goldstein, R. L., Ghobrial, M., and Busuttil, R. W. Fulminant liver failure due to usnic acid for weight loss. Am.J Gastroenterol. PubMed
- Neff, G. W., Reddy, K. R., Durazo, F. A., Meyer, D., Marrero, R., and Kaplowitz, N. Severe hepatotoxicity associated with the use of weight loss diet supplements containing ma huang or usnic acid. J Hepatol. 2004;41(6):1062-1064. PubMed
- Hsu, L. M., Huang, Y. S., Chang, F. Y., and Lee, S. D. 'Fat burner' herb, usnic Acid, induced acute hepatitis in a family. J Gastroenterol.Hepatol. 2005;20(7):1138-1139. PubMed
- Arneborn, P., Jansson, A., and Bottiger, Y. [Acute hepatitis in a woman after intake of slimming pills bought via Internet]. Lakartidningen 7-11-2005;102(28-29):2071-2072.
- Sanchez, W., Maple, J. T., Burgart, L. J., and Kamath, P. S. Severe hepatotoxicity associated with use of a dietary supplement containing usnic acid. Mayo Clin Proc 2006;81(4):541-544. PubMed
- Rafanelli, S., Bacchilega, R., Stanganelli, I., and Rafanelli, A. Contact dermatitis from usnic acid in vaginal ovules. Contact Dermatitis 1995;33(4):271-272. PubMed
- Schubert S, Schnuch A, Bauer A, et al. Very late reactions in the patch test with fragrance mix I and oak moss absolute (Evernia prunastri, INCI): Data of the Information Network of Departments of Dermatology (IVDK). Contact Dermatitis 2022;86(1):54-57.
Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
Taking Oak Moss and Erlotinib Together: Common Questions
Is it safe to take Oak Moss with Erlotinib?
Do Oak Moss and Erlotinib have any of the same side effects?
Should I take Oak Moss and Erlotinib at the same time of day?
Does Erlotinib interact with any supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.