Medication interaction hub

What Supplements Interact with Dextromethorphan, Methscopolamine, Phenylephrine?

Dextromethorphan, Methscopolamine, Phenylephrine brand name: DA Chewable. Every interaction below applies to the brands too.

220 Interactions 10 Major 166 Moderate 44 Minor
Curated & coded by · Clinical Pharmacist · Updated September 15, 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, Methscopolamine, Phenylephrine? 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, Methscopolamine, Phenylephrine 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 methscopolamine and phenylephrine (DA Chewable) packs a cough suppressant, a drying agent, and a decongestant into one tablet, which gives supplements several distinct ways to cause trouble, so I treat this as a list deserving real caution. Grapefruit can drive levels of the drug up by blocking its breakdown, St. John's wort can strip its effect, and stimulant herbs, plus plain caffeine, stack onto the decongestant, pushing heart rate and blood pressure higher.

Drying anticholinergic herbs add to the methscopolamine's side effects (dry mouth, constipation, confusion in older adults), and a smaller group raises serotonin alongside the dextromethorphan. A few entries block absorption outright, so space those well apart from your dose. The list runs to 220 ingredients, and while 166 rate moderate and 44 minor, the 10 rated major are the ones to understand first.

— , Clinical Pharmacist · July 18, 2026

Major 10 Moderate 166 Minor 44 No known interaction 1,232

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, Methscopolamine, Phenylephrine: Top Interactions at a Glance

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

Showing the 12 highest-ranked of 220 interacting ingredients — plus 1,232 more checked with no known interaction. See the complete ranked list.

Start here

The Major Interactions to Know About

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

Major Likelihood Likely Grapefruit + Dextromethorphan, Methscopolamine, Phenylephrinei

Grapefruit juice can increase levels of drugs metabolized by CYP3A4.

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

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 Ephedra + Dextromethorphan, Methscopolamine, Phenylephrinei

Theoretically, concomitant use might increase the risk for serious adverse effects.

Read the full interaction Major Likelihood Probable Henbane + Dextromethorphan, Methscopolamine, Phenylephrinei

Concomitant use of henbane can have additive anticholinergic effects and adverse effects with amantadine, antihistamines, atropine, belladonna alkaloids, hyoscy...

Read the full interaction Major Likelihood Probable Lithium + Dextromethorphan, Methscopolamine, Phenylephrinei

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

Read the full interaction Major Likelihood Probable Peyote + Dextromethorphan, Methscopolamine, Phenylephrinei

Concomitant use of peyote with stimulant drugs may increase the risk of adverse CNS effects.

Read the full interaction
The complete list

Every Supplement Checked Against Dextromethorphan, Methscopolamine, Phenylephrine

All 1,452 ingredients in our database, ranked by severity — 220 with a Dextromethorphan, Methscopolamine, Phenylephrine interaction on file and 1,232 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, Methscopolamine, Phenylephrine?

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 Dhea with Dextromethorphan, Methscopolamine, Phenylephrine?

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

Full Dhea + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take Dimethylhexylamine (dmha) with Dextromethorphan, Methscopolamine, Phenylephrine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, combining DMHA with stimulant drugs might increase the risk of adverse cardiovascular effects.

Full Dimethylhexylamine (dmha) + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take Diosmin with Dextromethorphan, Methscopolamine, Phenylephrine?

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

Full Diosmin + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take Echinacea with Dextromethorphan, Methscopolamine, Phenylephrine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Echinacea may induce hepatic CYP3A4 and inhibit intestinal CYP3A4.

Full Echinacea + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take English Ivy with Dextromethorphan, Methscopolamine, Phenylephrine?

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

Full English Ivy + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take Ergot with Dextromethorphan, Methscopolamine, Phenylephrine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Certain ergot alkaloids, such as dihydroergotamine, act as serotonin agonists.

Full Ergot + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take Eucalyptus with Dextromethorphan, Methscopolamine, Phenylephrine?

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

Full Eucalyptus + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take European Barberry with Dextromethorphan, Methscopolamine, Phenylephrine?

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

Full European Barberry + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take Evodia with Dextromethorphan, Methscopolamine, Phenylephrine?

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

Full Evodia + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take False Unicorn with Dextromethorphan, Methscopolamine, Phenylephrine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. In vitro, false unicorn extract inhibits cytochrome P450 2D6 (CYP2D6) activity.

Full False Unicorn + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take Fennel with Dextromethorphan, Methscopolamine, Phenylephrine?

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

Full Fennel + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take Fermented Wheat Germ Extract with Dextromethorphan, Methscopolamine, Phenylephrine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use of fermented wheat germ extract with serotonergic medications may increase the risk of serotonergic adverse e...

Full Fermented Wheat Germ Extract + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take Feverfew with Dextromethorphan, Methscopolamine, Phenylephrine?

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

Full Feverfew + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take Fo-ti with Dextromethorphan, Methscopolamine, Phenylephrine?

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

Full Fo-ti + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take Garcinia with Dextromethorphan, Methscopolamine, Phenylephrine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, combining garcinia with other serotonergic drugs might increase the risk of serotonergic side effects, including serotonin sy...

Full Garcinia + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take Garlic with Dextromethorphan, Methscopolamine, Phenylephrine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, garlic products containing allicin might induce intestinal CYP3A4 and inhibit hepatic CYP3A4.

Full Garlic + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take German Chamomile with Dextromethorphan, Methscopolamine, Phenylephrine?

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

Full German Chamomile + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take Ginger with Dextromethorphan, Methscopolamine, Phenylephrine?

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

Full Ginger + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take Ginkgo with Dextromethorphan, Methscopolamine, Phenylephrine?

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

Full Ginkgo + Dextromethorphan, Methscopolamine, Phenylephrine answer

Can you take Goji with Dextromethorphan, Methscopolamine, Phenylephrine?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, goji berry might inhibit CYP2D6 and reduce metabolism of CYP2D6 substrates.

Full Goji + Dextromethorphan, Methscopolamine, Phenylephrine 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, Methscopolamine, Phenylephrine is classified into the pharmacology categories it belongs to, (2) every supplement interaction documented against any of those categories is inherited by Dextromethorphan, Methscopolamine, Phenylephrine, 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, Methscopolamine, Phenylephrine sits in 10 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, Methscopolamine, Phenylephrine 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, Methscopolamine, Phenylephrine through this category.

Stimulant Drugs 44 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.

44 of the supplement ingredients on this page reach Dextromethorphan, Methscopolamine, Phenylephrine through this category.

Anticholinergic Drugs 30 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.

30 of the supplement ingredients on this page reach Dextromethorphan, Methscopolamine, Phenylephrine 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, Methscopolamine, Phenylephrine 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, Methscopolamine, Phenylephrine 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, Methscopolamine, Phenylephrine through this category.

Scopolamine (Transderm Scop) 2 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.

2 of the supplement ingredients on this page reach Dextromethorphan, Methscopolamine, Phenylephrine through this category.

Alpha-Adrenergic Agonists 1 ingredient

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.

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

Check a real product

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

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, Methscopolamine, Phenylephrine.

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Pharmacist Counseling Corner

Dextromethorphan, Methscopolamine, Phenylephrine & Supplements: Common Questions

What supplements interact with Dextromethorphan, Methscopolamine, Phenylephrine?
More than you might expect — 220 in total, though they are far from equal: 10 are rated major, 166 moderate, and 44 minor. The ranked list on this page puts the ones that genuinely matter first, and every entry opens a full report on that exact pair. The highest-ranked right now: Grapefruit, Activated Charcoal, Ephedra.
Which Dextromethorphan, Methscopolamine, Phenylephrine supplement interactions are the most serious?
Focus on the major group: Grapefruit, Activated Charcoal, Ephedra, Henbane and Lithium, among others. A major rating means the combination can be clinically significant, not that harm is guaranteed — but it's exactly the kind of thing to run past your pharmacist before your next dose, not after. Jump to the ranked list.
Can I take vitamins or supplements while on Dextromethorphan, Methscopolamine, Phenylephrine?
Usually yes — most people on Dextromethorphan, Methscopolamine, Phenylephrine can take most supplements. The catch is the exceptions, and they aren't always the exotic ones (St. John's Wort trips up more prescriptions than almost anything sold next to it). Look up each ingredient you actually take in the list above, and treat "no known interaction" as a green-ish light, not a guarantee. Try the label scanner or the interaction checker.
Do brands like DA Chewable have the same supplement interactions as Dextromethorphan, Methscopolamine, Phenylephrine?
Yes — DA Chewable all contain Dextromethorphan, Methscopolamine, Phenylephrine, 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, Methscopolamine, Phenylephrine and my other medications?
This page covers Dextromethorphan, Methscopolamine, Phenylephrine against supplements and herbal ingredients. Checking Dextromethorphan, Methscopolamine, Phenylephrine 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 15, 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.