Medication interaction hub

What Supplements Interact with Dextromethorphan, Guaifenesin?

Dextromethorphan, Guaifenesin brand names: Sudal DM, Touro DM, Queltuss, Fenesin DM, Monafed DM, and others. Every interaction below applies to the brands too.

171 Interactions 4 Major 125 Moderate 42 Minor
Curated & coded by · Clinical Pharmacist · Updated October 2, 2026

Drug–supplement interaction data sourced from Natural Medicines Pro, the licensed clinical database from TRC Healthcare / Therapeutic Research, with additional analysis by the HelloPharmacist Pharmacist Team. Our sources · Editorial policy

What is this page for?

One answer, for one medication: what supplements and herbal products interact with Dextromethorphan, Guaifenesin? Every vitamin, herb, and supplement ingredient we’ve checked against it is on this page, ranked by severity, each linking to the full report for that exact pair.

This page covers supplement interactions only — to check Dextromethorphan, Guaifenesin against your other medications, use the drug–drug interaction checker. Educational information from our licensed clinical databases, not medical advice. Our editorial policy

HelloPharmacist Bottom Line
Our Pharmacist Explains
What is this? The interaction data in the HelloPharmacist supplement database is licensed from Natural Medicines Pro by TRC Healthcare (Therapeutic Research). HelloPharmacist pharmacists often add our own analysis and context on top of that licensed data — such as this Bottom Line summary and the notes on individual interaction pages — and any such commentary is noted as ours.

Dextromethorphan with guaifenesin (Sudal DM, Touro DM, Queltuss, and others) sounds too ordinary a cough medicine to tangle badly with supplements, yet 4 of the 171 ingredients on this list rate major and belong at the top of your reading. Grapefruit and St. John's wort change how the body handles the drug, one raising its level, the other lowering it, and activated charcoal can soak the medicine up before it absorbs. The fourth major involves serotonin, which matters because dextromethorphan itself acts on serotonin.

The remaining 125 moderate and 42 minor entries mostly echo those patterns at lower stakes. Over a hundred can nudge the drug's blood level up or down through the enzymes that clear it, meaning extra dizziness or drowsiness if levels climb. Around 20 add to the serotonin effect, and a small set of fibers and charcoals blunt absorption, so keep those well separated from any dose.

— , Clinical Pharmacist · July 18, 2026

Major 4 Moderate 125 Minor 42 No known interaction 1,281

This box checks one ingredient at a time (like turmeric or magnesium). Taking a supplement product with a whole label of ingredients? Search the product instead — we check every ingredient on it ↓

Top Ingredient Interactions

Dextromethorphan, Guaifenesin: Top Interactions at a Glance

The most significant Dextromethorphan, Guaifenesin supplement & herbal interactions, colored by severity. Tap any ingredient to open the full report for that pair.

Showing the 12 highest-ranked of 171 interacting ingredients — plus 1,281 more checked with no known interaction. See the complete ranked list.

Start here

The Major Interactions to Know About

The most clinically significant Dextromethorphan, Guaifenesin + supplement combinations in our database, best-documented first. Open any card for the full report.

Major Likelihood Likely Grapefruit + Dextromethorphan, Guaifenesini

Grapefruit juice can increase levels of drugs metabolized by CYP3A4.

Read the full interaction Major Likelihood Probable Activated Charcoal + Dextromethorphan, Guaifenesini

Activated charcoal reduces systemic exposure to many drugs, including those that undergo enterohepatic recirculation, regardless of the route of administration.

Read the full interaction Major Likelihood Probable Lithium + Dextromethorphan, Guaifenesini

Theoretically, taking lithium supplements with serotonergic drugs might both mask and increase the risk of serotonin syndrome.

Read the full interaction Major Likelihood Probable St. John's Wort + Dextromethorphan, Guaifenesini

St.

Read the full interaction
The complete list

Every Supplement Checked Against Dextromethorphan, Guaifenesin

All 1,452 ingredients in our database, ranked by severity — 171 with a Dextromethorphan, Guaifenesin interaction on file and 1,281 with none found. Filter by severity or search any ingredient; hover the for what each ingredient is.

Looking for an interaction with a specific supplement product? Search products instead ↓

Straight answers

Can You Take It With Dextromethorphan, Guaifenesin?

One-line answers, one card per combination — scroll through today’s 20 and tap any card for the full report. A different set rotates in daily until every combination has had its turn.

Can you take Kratom with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking kratom in combination with serotonergic drugs may increase levels of serotonin, increasing the risk of serotonin syndr...

Full Kratom + Dextromethorphan, Guaifenesin answer

Can you take Rauvolfia Vomitoria with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, Rauvolfia vomitoria might increase the levels and clinical effects of CYP2D6 substrates.

Full Rauvolfia Vomitoria + Dextromethorphan, Guaifenesin answer

Can you take Rauwolscine with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, rauwolscine might increase levels of drugs metabolized by CYP2D6.

Full Rauwolscine + Dextromethorphan, Guaifenesin answer

Can you take Resveratrol with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.

Full Resveratrol + Dextromethorphan, Guaifenesin answer

Can you take Rooibos with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking rooibos with CYP2D6 substrates may increase the effects of CYP2D6 substrates.

Full Rooibos + Dextromethorphan, Guaifenesin answer

Can you take Sage with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, sage might increase the levels and clinical effects of drugs metabolized by CYP2D6.

Full Sage + Dextromethorphan, Guaifenesin answer

Can you take Same with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Taking SAMe with serotonergic drugs might increase the risk of serotonin syndrome and other serotonergic side effects.

Full Same + Dextromethorphan, Guaifenesin answer

Can you take Schizonepeta with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Animal research suggests that schizonepetin, a monoterpene constituent of schizonepeta, inhibits cytochrome P450 (CYP) 2D6.

Full Schizonepeta + Dextromethorphan, Guaifenesin answer

Can you take Shiitake Mushroom with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, shiitake mushroom might decrease levels of drugs metabolized by CYP2D6.

Full Shiitake Mushroom + Dextromethorphan, Guaifenesin answer

Can you take Slippery Elm with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.

Full Slippery Elm + Dextromethorphan, Guaifenesin answer

Can you take Sulforaphane with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, sulforaphane might increase the levels and effects of CYP3A4 substrates.

Full Sulforaphane + Dextromethorphan, Guaifenesin answer

Can you take Sweet Annie with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Sweet Annie may alter plasma levels and clinical effects of drugs metabolized by CYP3A4.

Full Sweet Annie + Dextromethorphan, Guaifenesin answer

Can you take Terminalia with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, use of Terminalia arjuna may increase the levels and clinical effects of CYP2D6 substrates.

Full Terminalia + Dextromethorphan, Guaifenesin answer

Can you take Thunder God Vine with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, thunder god vine might increase the levels and clinical effects of CYP3A4 substrates.

Full Thunder God Vine + Dextromethorphan, Guaifenesin answer

Can you take Tinospora Cordifolia with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, Tinospora cordifolia might increase levels of drugs metabolized by CYP2D6.

Full Tinospora Cordifolia + Dextromethorphan, Guaifenesin answer

Can you take Tragacanth with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, tragacanth might alter absorption of oral drugs.

Full Tragacanth + Dextromethorphan, Guaifenesin answer

Can you take Turmeric with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Turmeric might increase or decrease levels of drugs metabolized by CYP3A4.

Full Turmeric + Dextromethorphan, Guaifenesin answer

Can you take Uva Ursi with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, uva ursi may decrease the metabolism of CYP3A4 substrates.

Full Uva Ursi + Dextromethorphan, Guaifenesin answer

Can you take Vitamin E with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, vitamin E might induce metabolism of CYP3A4, possibly reducing the levels CYP3A4 substrates.

Full Vitamin E + Dextromethorphan, Guaifenesin answer

Can you take White Pepper with Dextromethorphan, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. In vitro evidence suggests that some constituents of white pepper inhibit cytochrome P450 2D6 (CYP2D6).

Full White Pepper + Dextromethorphan, Guaifenesin answer
Read the list like a pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each entry links to a full report with the clinical detail, likelihood, evidence level, and citations for that exact combination.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

How Does Our Interaction Checker Work?

Behind every verdict on this page is a category system. Our source database doesn’t document supplement interactions drug-by-drug — it documents them against groups of medications that behave the same way (for example, “drugs processed by the CYP3A4 liver enzyme” or “blood-thinning medications”).

So the check works in three steps: (1) Dextromethorphan, Guaifenesin is classified into the pharmacology categories it belongs to, (2) every supplement interaction documented against any of those categories is inherited by Dextromethorphan, Guaifenesin, and (3) each ingredient keeps its own severity, likelihood, and evidence grades from the underlying record. That’s why one supplement can carry several records for one drug — it may interact through more than one category.

Dextromethorphan, Guaifenesin sits in 6 interaction categories. Open any one to see what the group means:

Cytochrome P450 3A4 (Cyp3A4) Substrates 121 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

121 of the supplement ingredients on this page reach Dextromethorphan, Guaifenesin through this category.

Cytochrome P450 2D6 (Cyp2D6) Substrates 60 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

60 of the supplement ingredients on this page reach Dextromethorphan, Guaifenesin through this category.

Serotonergic Drugs 20 ingredients

Medications that raise serotonin activity. Combining them with serotonin-active supplements can, in rare cases, push serotonin too high.

20 of the supplement ingredients on this page reach Dextromethorphan, Guaifenesin through this category.

Oral Drugs 17 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

17 of the supplement ingredients on this page reach Dextromethorphan, Guaifenesin through this category.

Dextromethorphan (Robitussin Dm, Others) 9 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

9 of the supplement ingredients on this page reach Dextromethorphan, Guaifenesin through this category.

Serotonergic Drugs 1 ingredient

Medications that raise serotonin activity. Combining them with serotonin-active supplements can, in rare cases, push serotonin too high.

1 of the supplement ingredient on this page reaches Dextromethorphan, Guaifenesin through this category.

Check a real product

Take a Supplement Product? Check the Whole Bottle Against Dextromethorphan, Guaifenesin

Most supplements are combination products — and the interaction may come from an ingredient you didn’t buy it for. Search any product below (or scan its label) and we’ll check every ingredient on it against Dextromethorphan, Guaifenesin.

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Pharmacist Counseling Corner

Dextromethorphan, Guaifenesin & Supplements: Common Questions

What supplements interact with Dextromethorphan, Guaifenesin?
In our interaction database, 171 supplement and herbal ingredients have an interaction with Dextromethorphan, Guaifenesin on file — 4 rated major, 125 moderate, and 42 minor. That number sounds scarier than it is: severity matters far more than the count, which is why the list on this page is ranked instead of alphabetical. Start at the top. The highest-ranked right now: Grapefruit, Activated Charcoal, Lithium.
Which Dextromethorphan, Guaifenesin supplement interactions are the most serious?
The 4 major-rated combinations — led by Grapefruit, Activated Charcoal, Lithium and St. John's Wort — deserve real caution: these are the ones generally best avoided, or used only with your prescriber watching. If you take any of them today, don't panic and don't stop anything abruptly — call your pharmacist first. Jump to the ranked list.
Can I take vitamins or supplements while on Dextromethorphan, Guaifenesin?
That depends entirely on which supplement. The honest answer for Dextromethorphan, Guaifenesin is in the ranked list above — and if what you take is a combination product with a dozen ingredients, don't check them one by one: photograph the label with our scanner and we'll check the whole thing at once. Try the label scanner or the interaction checker.
Do brands like Sudal DM have the same supplement interactions as Dextromethorphan, Guaifenesin?
Yes — Sudal DM, Touro DM, Queltuss, Fenesin DM, Monafed DM and other brands all contain Dextromethorphan, Guaifenesin, so everything on this page applies to them equally. Interactions belong to the active drug, never to the brand on the box; the same is true of generics.
Where do these interaction ratings come from?
Every rating comes from the Natural Medicines database — the same evidence-graded reference pharmacists and hospitals use — and each interaction carries three separate grades: severity (how bad it can be), likelihood (how well it's documented in studies and case reports), and an evidence level. Our pharmacists review the content; we never let an AI decide an interaction. See how to read the ratings and our editorial policy.
What about Dextromethorphan, Guaifenesin and my other medications?
This page covers Dextromethorphan, Guaifenesin against supplements and herbal ingredients. Checking Dextromethorphan, Guaifenesin against your other prescription or OTC medications is a different tool — our drug interaction checker covers that side. Head to the drug–drug interaction checker.

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

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Sourcing

Where This Data Comes From — and Why You Can Trust It

🧪 Licensed clinical database

Every interaction verdict on this page comes from Natural Medicines Pro (TRC Healthcare / Therapeutic Research) — the same evidence-graded reference used by pharmacists and hospitals. We license this data directly; we do not scrape it, and no AI invents an interaction.

🧑‍⚕️ Pharmacist review

This page is curated and coded by , Clinical Pharmacist, with additional analysis by the HelloPharmacist Pharmacist Team. Editorial commentary is ours; the licensed interaction records are shown as sourced.

🔄 Kept current

Our interaction database refreshes on a weekly cycle, and this page re-checks the live database every time it’s rebuilt — what you see reflects the database as of October 2, 2026.

🔍 Full transparency

How every dataset on this site is sourced, licensed, and updated is documented publicly: our data sources · editorial policy · how we use AI.

Educational information, not medical advice. An interaction being on file does not mean it will happen to you — and absence of one is not proof of safety. Never start or stop a medication or supplement without talking to your pharmacist or doctor.