Drug & supplement interaction

Mountain Laurel + Dextromethorphan

Dextromethorphan brand names: Hold, Benylin Adult, Benylin Pediatric, Theraflu Thin Strips Long Acting Cough, Neo Citran Thin Strips Cough.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Mountain Laurel and Dextromethorphan 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.

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Interaction report

Mountain Laurel and Dextromethorphan

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 Dextromethorphan and Mountain Laurel 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 Mountain Laurel at all — not against Dextromethorphan, 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.

Mountain Laurel safety at a glance

Mountain Laurel overall Avoid All parts of the plant are poisonous due to grayanotoxins and should not be taken internally.
Pregnancy Unsafe When used orally. There is insufficient reliable information available about safety of mountain laurel for topical use; avoid using. Read the full pregnancy detail
Breastfeeding Unsafe When used orally. There is insufficient reliable information available about safety of mountain laurel for topical use; avoid using. Read the full breastfeeding detail

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.

Still wondering about combining Dextromethorphan and Mountain Laurel? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Mountain Laurel Itself Has Been Linked To

This is not an interaction — nothing below involves Dextromethorphan. It is the side-effect record for Mountain Laurel on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Mountain Laurel, this list is the first place to look. One entry is worth acting on rather than waiting out — marked below.

  • Loss of vision / Muscle weakness / A slow heartbeat / An irregular heartbeat Worth acting on Additional detail

    “Orally, mountain laurel can result in painful oral and gastric mucous membranes, increased salivation, cold sweat, nausea, vomiting, diarrhea, and paresthesias (18). Dizziness; headache; fever attacks; and intoxicated states with temporary loss of vision, muscle weakness, coordination disorders, and spasms can also develop.”

    Mountain Laurel · Natural Medicines adverse-effect record, reported in arrhythmia.

    1 source cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  • Sweating / Low blood pressure / Fever / Dizziness / Diarrhea / Vomiting Additional detail

    Recorded for Mountain Laurel in the same Natural Medicines adverse-effect record shown under Loss of vision / Muscle weakness / A slow heartbeat / An irregular heartbeat above.

Showing the 10 most notable of 12 recorded effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

Everything above comes from the Natural Medicines adverse-effect record for Mountain Laurel — expand a row for the licensed statement it rests on. We haven’t matched Dextromethorphan to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Dextromethorphan.

Special populations

Mountain Laurel in Pregnancy & Breastfeeding

Pregnancy And Lactation Unsafe

When used orally. There is insufficient reliable information available about safety of mountain laurel for topical use; avoid using.

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

From our Q&A

Questions About Mountain Laurel or Dextromethorphan

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Mountain Laurel or Dextromethorphan, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Dextromethorphan

This page covers Mountain Laurel only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Dextromethorphan page lists 171 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), Lithium (major), St. John's Wort (major) and 1,3-dmaa (moderate).

By severity: 4 major · 125 moderate · 42 minor.

From our pharmacist’s overview on the Dextromethorphan page

“A glass of grapefruit juice can push dextromethorphan (Benylin, Hold, and other cough medicines) to higher levels than intended, one of four major-rated entries among the 171 supplements and herbs on file, and the list as a whole warrants real care. Most interactions trace back to the liver enzymes (CYP3A4 and CYP2D6) that clear dextro…”

Reviewed by 2 · Jul 18, 2026

Open the Dextromethorphan interaction page

One more smart check

Taking Mountain Laurel as Part of a Dietary Supplement Product? Check It for Interactions

We hold 2 real supplement products containing Mountain Laurel, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Mountain Laurel. Even though Mountain Laurel itself has no known interaction with Dextromethorphan, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Mountain Laurel and Dextromethorphan 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.

Supplement Mountain Laurel
Steady interest

#1,061 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Dextromethorphan
Top 25%

#538 of 2,830 medications looked up here in the last 7 days

29 days ago today

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 Mountain Laurel reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Mountain Laurel and Dextromethorphan 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.
Data structure & sourcing designed and verified by .
Supplement

About Mountain Laurel

What is Mountain Laurel?

  • Skin conditions (folk use)
  • Pain and inflammation (folk use)
  • Diarrhea (historical folk use)
  • Fever (historical folk use)

Mountain Laurel is a flowering shrub native to North America that contains toxic compounds called grayanotoxins, making it dangerous to eat or use internally. There is no reliable evidence that it is safe or effective as a supplement, and poisoning can be serious. We strongly recommend avoiding it.

Kalmia latifolia · Ericaceae · Leaves (historically); rarely used today · Not commonly available as a supplement; historically used as crude leaf preparations or tinctures

An interaction check asks whether these two react with each other — it does not ask whether Mountain Laurel is a good idea for someone in your situation. Here is what our Mountain Laurel record says about it on its own.

Mountain Laurel: dosing

There is no established or safe dose of Mountain Laurel for any use. It is not recommended as a dietary supplement, and no standardized preparations are considered safe to take internally.Because of its toxicity, the safest approach is to avoid using it altogether.

From our Mountain Laurel monograph — the full record covers uses, side effects and every documented interaction.

Read the full Mountain Laurel monograph & all interactions
Medication

About Dextromethorphan

What Is Dextromethorphan Used For?

Brand names: Hold, Benylin Adult, Benylin Pediatric, Theraflu Thin Strips Long Acting Cough, Neo Citran Thin Strips Cough

Dextromethorphan temporarily relieves cough due to minor throat and bronchial irritation, such as the kind that comes with the common cold or breathing in irritants. It also helps reduce the urge to cough so you — or your child — can get to sleep.

Some products, including CVS Long Acting Cough and Premier Value Tussin Cough oral liquids, are also indicated to help loosen phlegm (mucus) and thin bronchial secretions to help drain the airways.

See full Dextromethorphan drug information
Keep checking

Other Drugs & Mountain Laurel

Browse every other medication we’ve checked against Mountain Laurel — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
0Moderate
0Minor
2,829No known interaction
No interaction 2,829 drugs checked — show the list
Evidence & sources

Mountain Laurel References

The 1 references that drive our Mountain Laurel 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.

  1. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

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.

Pharmacist Counseling Corner

Taking Mountain Laurel and Dextromethorphan Together: Common Questions

Is it safe to take Mountain Laurel with Dextromethorphan?
We do not list a known interaction between Mountain Laurel and Dextromethorphan. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Does Dextromethorphan interact with any supplements?
Yes. Dextromethorphan has documented interactions with 171 supplements in our database — Mountain Laurel is not one of them. The Dextromethorphan interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Dextromethorphan and Mountain Laurel?

Our pharmacists answer your medication & supplement questions — free.

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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.