Drug & supplement interaction

Larch Arabinogalactan + Dextromethorphan

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

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Larch Arabinogalactan 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

Larch Arabinogalactan 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 Larch Arabinogalactan 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.

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.

Larch Arabinogalactan safety at a glance

Larch Arabinogalac... overall Use caution Generally well tolerated as a fiber, but high-quality long-term safety data are limited.
Pregnancy Use caution Not enough safety data, so it is best to avoid unless your doctor approves.
Breastfeeding Use caution Not enough safety data, so caution and provider guidance are advised.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Dextromethorphan and Larch Arabinogalactan? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Dextromethorphan

Interactions in our licensed database are recorded against drug classes, not just single drug names. Dextromethorphan is filed under 6 classifications — including serotonergic drugs, serotonergic drugs, cytochrome p450 2d6 (cyp2d6) substrates. Larch Arabinogalactan has documented interactions with 1 drug class — the most serious being immunosuppressants (moderate) — and none of Dextromethorphan’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Larch Arabinogalactan Does Interact With Other Medications

Larch Arabinogalactan has 121 moderate known drug interactions in our database — Dextromethorphan isn’t one of them. If you take anything else, check it against the full list below.

Moderate 121 No known interaction 2,709 (incl. Dextromethorphan)
Taking anything else?

Check Another of Your Medications Against Larch Arabinogalactan

Covers the 2,830 medications we’ve checked against Larch Arabinogalactan. Pick one to open its full report.

What to actually watch for

What Larch Arabinogalactan Itself Has Been Linked To

This is not an interaction — nothing below involves Dextromethorphan. It is the side-effect record for Larch Arabinogalactan on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Larch Arabinogalactan, this list is the first place to look.

  • Bloating or gas Additional detail

    “Orally, larch arabinogalactan is generally well tolerated. Some people can experience bloating and flatulence.”

    Larch Arabinogalactan · Natural Medicines adverse-effect record, reported in flatulence.

    3 sources cited
    1. 3530. Kelly GS. Larch arabinogalactan: Clinical relevance of a novel immune-enhancing polysaccharide. Alt Med Rev 1999;4:96-103.
    2. 17370. Udani JK, Singh BB, Barrett ML, Singh VJ. Proprietary arabinogalactan extract increases antibody response to the pneumonia vaccine: a randomized, double-blind, placebo-controlled, pilot study in healthy volunteers. Nutr J 2010;9:32. PubMed
    3. 93102. Grube B, Stier H, Riede L, Gruenwald J. Tolerability of a proprietary larch arabinogalactan extract: a randomized, double-blind, placebo-controlled clinical trial in healthy subjects. Food Nutr Sci 2012;3:1533-8. DOI

    “Orally, larch arabinogalactan can cause bloating and flatulence.”

    Larch Arabinogalactan · Natural Medicines adverse-effect record, reported in flatulence.

    1 source cited
    1. 3530. Kelly GS. Larch arabinogalactan: Clinical relevance of a novel immune-enhancing polysaccharide. Alt Med Rev 1999;4:96-103.

Everything above comes from the Natural Medicines adverse-effect record for Larch Arabinogalactan — 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.

Overlapping uses

What Dextromethorphan Is Prescribed For, and What Larch Arabinogalactan Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Dextromethorphan is a prescription medicine with approved uses on its FDA label. Larch Arabinogalactan is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Dextromethorphan is prescribed for: 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.

Larch Arabinogalactan has been studied for:

  • Common cold studied, not established Larch Arabinogalactan has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Larch Arabinogalactan for common cold

    Preliminary clinical research shows that taking a specific larch arabinogalactan extract (ResistAid, Lonza Ltd.) 4.5 grams daily for 12 weeks does not significantly decrease the number, intensity, or symptoms of common colds when compared with placebo in patients who frequently suffer from colds. However, larch arabinogalactan appears to increase the percentage of patients who experience no cold episodes.

    1 source cited
    1. 93104. Riede L, Grube B, Gruenwald J. Larch arabinogalactan effects on reducing incidence of upper respiratory tract infections. Curr Med Res Opin 2013;29(3):251-8.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Dextromethorphan on your own; if you are taking Larch Arabinogalactan for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Larch Arabinogalactan 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 Larch Arabinogalactan 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 Larch Arabinogalactan 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 Larch Arabinogalactan as Part of a Dietary Supplement Product? Check It for Interactions

We hold 717 real supplement products containing Larch Arabinogalactan, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Larch Arabinogalactan. Even though Larch Arabinogalactan 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 Larch Arabinogalactan 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 Larch Arabinogalactan
Top 25%

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

29 days ago today
Medication Dextromethorphan
Top 5%

#80 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 Larch Arabinogalactan reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Larch Arabinogalactan 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 Larch Arabinogalactan

What is Larch Arabinogalactan?

  • Immune support
  • Cold and flu prevention
  • Digestive and gut health
  • Source of soluble fiber
  • Prebiotic support

Larch arabinogalactan is a soluble fiber from larch trees that is mainly used as a prebiotic and for immune support. Early research is interesting but limited, and most claims are not yet firmly proven. It is generally well tolerated, but pregnant and breastfeeding people should be cautious and check with a healthcare provider first.

Larix occidentalis · Pinaceae · Wood (heartwood extract) · Powder, capsules, drink mix

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

Larch Arabinogalactan: dosing

There is no official, standardized dose for larch arabinogalactan. Amounts used in studies have varied, and it is often taken once or twice daily mixed into water or another drink.The best approach is to follow the directions on the product label and start with a lower amount to see how your body responds.

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

Read the full Larch Arabinogalactan 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 & Larch Arabinogalactan

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

0Major
121Moderate
0Minor
2,708No known interaction
121 Moderate 2,708 No interaction
Moderate

121 interactions

Showing 60 of 121 moderate interactions — see all 121 on the Larch Arabinogalactan page.

No interaction 2,708 drugs checked — show the list

We also checked Larch Arabinogalactan against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,708 medications checked with no known interaction — see the full Larch Arabinogalactan list.

See the full Larch Arabinogalactan interactions page
See every supplement checked against Dextromethorphan, ranked by severity
Evidence & sources

Larch Arabinogalactan References

The 8 references that drive our Larch Arabinogalactan 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. D'Adamo P. Larch arabinogalactan. J Naturopath Med 1996;6:33-7.
  2. Kelly GS. Larch arabinogalactan: Clinical relevance of a novel immune-enhancing polysaccharide. Alt Med Rev 1999;4:96-103.
  3. Marett R, Slavin JL. No long-term benefits of supplementation with arabinogalactan on serum lipids and glucose. J Am Diet Assoc 2004;104:636-9.
  4. Robinson RR, Feirtag J, Slavin JL. Effects of dietary arabinogalactan on gastrointestinal and blood parameters in healthy human subjects. J Am Coll Nutr 2001;20:279-85. PubMed
  5. Udani JK, Singh BB, Barrett ML, Singh VJ. Proprietary arabinogalactan extract increases antibody response to the pneumonia vaccine: a randomized, double-blind, placebo-controlled, pilot study in healthy volunteers. Nutr J 2010;9:32. PubMed
  6. Grube B, Stier H, Riede L, Gruenwald J. Tolerability of a proprietary larch arabinogalactan extract: a randomized, double-blind, placebo-controlled clinical trial in healthy subjects. Food Nutr Sci 2012;3:1533-8. DOI
  7. Dion C, Chappuis E, Ripoll C. Does larch arabinogalactan enhance immune function? A review of mechanistic and clinical trials. Nutr Metab (Lond) 2016;13:28. PubMed
  8. Riede L, Grube B, Gruenwald J. Larch arabinogalactan effects on reducing incidence of upper respiratory tract infections. Curr Med Res Opin 2013;29(3):251-8.

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 Larch Arabinogalactan and Dextromethorphan Together: Common Questions

Is it safe to take Larch Arabinogalactan with Dextromethorphan?
We do not list a known interaction between Larch Arabinogalactan 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.
Are Larch Arabinogalactan and Dextromethorphan used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Larch Arabinogalactan in each. That is a conversation for your prescriber, especially if Dextromethorphan is being adjusted to a target.
How was the Larch Arabinogalactan and Dextromethorphan combination checked?
Interactions in our licensed database are recorded against drug classes. Dextromethorphan is filed under 6 classifications, and Larch Arabinogalactan has documented interactions with 1 drug class — none of Dextromethorphan's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Larch Arabinogalactan interact with any other medications?
Yes. Larch Arabinogalactan has 121 documented drug interactions in our database — Dextromethorphan is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Dextromethorphan interact with any supplements?
Yes. Dextromethorphan has documented interactions with 171 supplements in our database — Larch Arabinogalactan 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

Where next

Keep Exploring

Larch Arabinogalactan monograph Uses, safety profile, and every drug interaction in one place Dextromethorphan drug information The full plain-English guide to this medication Dextromethorphan supplement interactions Every supplement checked against Dextromethorphan, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 8 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Dextromethorphan and Larch Arabinogalactan?

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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.