Medication interaction hub

What Supplements Interact with Dextromethorphan HBr, Guaifenesin?

Dextromethorphan HBr, Guaifenesin brand names: Vicks Formula 44E Cough & Chest Congestion Relief, Pediatric Vicks Formula 44e Cough & Chest Congesti. Every interaction below applies to the brands too.

171 Interactions 4 Major 125 Moderate 42 Minor
Curated & coded by · Clinical Pharmacist · Updated September 17, 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 HBr, 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 HBr, 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.

A bad cough tends to hit when supplements are already on the counter, and anyone reaching for Vicks Formula 44E (dextromethorphan HBr and guaifenesin) should treat this list with real care, since 4 of its 171 entries carry a major rating. Two themes dominate. Dextromethorphan affects serotonin, and about 20 of these ingredients do too, stacking toward serotonin syndrome, a risky serotonin overload. Far more, over 120, share the same liver enzymes (CYP3A4 and CYP2D6) that clear the drug, so they can push its level up or drop it. Grapefruit and St. John's wort are the everyday majors there.

Activated charcoal is the other major here; it grabs oral medicines in the gut and blunts absorption, so keep any dose well separated. The 125 moderate and 42 minor entries mostly repeat the enzyme and absorption themes at lower intensity, which is why the four majors are where I'd start reading.

— , Clinical Pharmacist · July 18, 2026

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

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Most Viewed Ingredient Interactions

Dextromethorphan HBr, Guaifenesin: Top Interactions at a Glance

The Dextromethorphan HBr, Guaifenesin supplement & herbal interactions people checked most in the last 24 hours, 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 Most-Checked Dextromethorphan HBr, Guaifenesin Combinations Today

The Dextromethorphan HBr, Guaifenesin + supplement pages people viewed most in the last 24 hours (resets at midnight). Open any card for the full report.

Moderate Likelihood Probable Cannabidiol (cbd) + Dextromethorphan HBr, Guaifenesini

Cannabidiol may increase levels of drugs that are metabolized by CYP3A4.

Read the full interaction Minor Likelihood Unlikely Gymnema + Dextromethorphan HBr, Guaifenesini

Theoretically, gymnema might increase levels of drugs metabolized by CYP3A4.

Read the full interaction Moderate Likelihood Possible Greater Celandine + Dextromethorphan HBr, Guaifenesini

Research in vitro shows that chelidonine, a constituent of greater celandine, inhibits cytochrome P450 2D6 (CYP2D6) enzyme activity.

Read the full interaction Moderate Likelihood Possible Indian Long Pepper + Dextromethorphan HBr, Guaifenesini

Theoretically, Indian long pepper might increase the effects and adverse effects of CYP3A4 substrates.

Read the full interaction Major Likelihood Likely Grapefruit + Dextromethorphan HBr, Guaifenesini

Grapefruit juice can increase levels of drugs metabolized by CYP3A4.

Read the full interaction Major Likelihood Probable Activated Charcoal + Dextromethorphan HBr, 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
The complete list

Every Supplement Checked Against Dextromethorphan HBr, Guaifenesin

All 1,452 ingredients in our database, ranked by severity — 171 with a Dextromethorphan HBr, 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 HBr, 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 Cannabidiol (cbd) with Dextromethorphan HBr, Guaifenesin?

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

Full Cannabidiol (cbd) + Dextromethorphan HBr, Guaifenesin answer

Can you take Gymnema with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, gymnema might increase levels of drugs metabolized by CYP3A4.

Full Gymnema + Dextromethorphan HBr, Guaifenesin answer

Can you take Greater Celandine with Dextromethorphan HBr, Guaifenesin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Research in vitro shows that chelidonine, a constituent of greater celandine, inhibits cytochrome P450 2D6 (CYP2D6) enzyme activity.

Full Greater Celandine + Dextromethorphan HBr, Guaifenesin answer

Can you take Indian Long Pepper with Dextromethorphan HBr, Guaifenesin?

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

Full Indian Long Pepper + Dextromethorphan HBr, Guaifenesin answer

Can you take Breadfruit with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, breadfruit might inhibit cytochrome P450 3A4 (CYP3A4) and increase levels of drugs metabolized by these enzymes; until more i...

Full Breadfruit + Dextromethorphan HBr, Guaifenesin answer

Can you take Carob with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, carob might also impair the absorption of oral drugs.

Full Carob + Dextromethorphan HBr, Guaifenesin answer

Can you take Cascara Sagrada with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, cascara sagrada might decrease the effects of CYP3A4 substrates.

Full Cascara Sagrada + Dextromethorphan HBr, Guaifenesin answer

Can you take Fucus Vesiculosus with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, concomitant use of Fucus vesiculosus with CYP2D6 substrates might alter the effects of these substrates.

Full Fucus Vesiculosus + Dextromethorphan HBr, Guaifenesin answer

Can you take Hemp with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, hemp might decrease the levels and clinical effects of CYP3A4 substrates.

Full Hemp + Dextromethorphan HBr, Guaifenesin answer

Can you take Hibiscus Sabdariffa with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, Hibiscus sabdariffa extract might reduce the metabolism of CYP2D6 substrates.

Full Hibiscus Sabdariffa + Dextromethorphan HBr, Guaifenesin answer

Can you take Honey with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, honey might decrease levels of drugs metabolized by CYP3A4, but research is conflicting.

Full Honey + Dextromethorphan HBr, Guaifenesin answer

Can you take Hops with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, hops extract might alter metabolism of CYP3A4 substrates; however, this effect may not be clinically significant.

Full Hops + Dextromethorphan HBr, Guaifenesin answer

Can you take Hordenine with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Hordenine weakly inhibits cytochrome P450 2D6 (CYP2D6) enzymes in vitro.

Full Hordenine + Dextromethorphan HBr, Guaifenesin answer

Can you take Karaya Gum with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Co-administration of oral drugs with bulk forming laxatives such as karaya gum may decrease, increase, or have no effect on the absorption o...

Full Karaya Gum + Dextromethorphan HBr, Guaifenesin answer

Can you take Marshmallow with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, mucilage in marshmallow might impair absorption of oral drugs.

Full Marshmallow + Dextromethorphan HBr, Guaifenesin answer

Can you take Melatonin with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, melatonin might increase levels of drugs metabolized by CYP2D6.

Full Melatonin + Dextromethorphan HBr, Guaifenesin answer

Can you take Passion Flower with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, passion flower might decrease the effects of CYP3A4 substrates.

Full Passion Flower + Dextromethorphan HBr, Guaifenesin answer

Can you take Puravive with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Puravive contains Panax ginseng.

Full Puravive + Dextromethorphan HBr, Guaifenesin answer

Can you take Rhodiola with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Theoretically, rhodiola might increase levels of drugs metabolized by CYP3A4.

Full Rhodiola + Dextromethorphan HBr, Guaifenesin answer

Can you take Valerian with Dextromethorphan HBr, Guaifenesin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. Valerian does not seem to have a clinically relevant effect on levels of drugs metabolized by CYP3A4.

Full Valerian + Dextromethorphan HBr, 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 HBr, Guaifenesin is classified into the pharmacology categories it belongs to, (2) every supplement interaction documented against any of those categories is inherited by Dextromethorphan HBr, 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 HBr, 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 HBr, 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 HBr, 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 HBr, 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 HBr, 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 HBr, 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 HBr, Guaifenesin through this category.

Check a real product

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

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Pharmacist Counseling Corner

Dextromethorphan HBr, Guaifenesin & Supplements: Common Questions

What supplements interact with Dextromethorphan HBr, Guaifenesin?
In our interaction database, 171 supplement and herbal ingredients have an interaction with Dextromethorphan HBr, 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 HBr, 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 HBr, Guaifenesin?
That depends entirely on which supplement. The honest answer for Dextromethorphan HBr, 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 Vicks Formula 44E Cough & Chest Congestion Relief have the same supplement interactions as Dextromethorphan HBr, Guaifenesin?
Yes — Vicks Formula 44E Cough & Chest Congestion Relief, Pediatric Vicks Formula 44e Cough & Chest Congesti all contain Dextromethorphan HBr, 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 HBr, Guaifenesin and my other medications?
This page covers Dextromethorphan HBr, Guaifenesin against supplements and herbal ingredients. Checking Dextromethorphan HBr, 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 September 17, 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.