Drug & supplement interaction

Iboga + Dextromethorphan, Guaifenesin, Pseudoephedrine

Dextromethorphan, Guaifenesin, Pseudoephedrine brand names: Pseudovent DM, Profen Forte DM, Profen II DM, Med Rx DM, Protuss DM, and others.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Iboga has a moderate interaction with Dextromethorphan, Guaifenesin, Pseudoephedrine. Theoretically, taking iboga with serotonergic drugs might increase levels of serotonin, resulting in additive effects with serotonergic drugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Iboga and Dextromethorphan, Guaifenesin, Pseudoephedrine

Here is the interaction we found between these two, with the evidence behind it.

Moderate

SEROTONERGIC DRUGS

Why this applies to Dextromethorphan, Guaifenesin, Pseudoephedrine

Dextromethorphan, Guaifenesin, Pseudoephedrine falls under SEROTONERGIC DRUGS — the group Iboga interacts with.

Theoretically, taking iboga with serotonergic drugs might increase levels of serotonin, resulting in additive effects with serotonergic drugs.
Ibogaine, a constituent in iboga, has serotonergic effects. Theoretically, combining serotonergic drugs with iboga might increase the risk of serotonergic side effects, including serotonin syndrome and cerebral vasoconstrictive disorders. Monitor patients for signs of serotonin syndrome and other serotonergic side effects if using iboga with serotonergic drugs.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the piece that matters in your combo cough and cold product: the dextromethorphan. It nudges serotonin levels up in the brain, and Iboga (through ibogaine) does the same thing. Stack two serotonin-raising things together and you can theoretically push serotonin too high, a state called serotonin syndrome. Warning signs include agitation, a racing heart, sweating, shivering, muscle twitching, and confusion.

I'll be honest, this concern is based on how these two work on paper, not on solid human studies, so the real-world risk is uncertain. That said, Iboga also carries its own serious heart rhythm dangers and isn't legal here. The pseudoephedrine and guaifenesin aren't the issue. Please run this by your pharmacist or doctor before mixing anything with Iboga.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Glick SD, Maisonneuve IS. Mechanisms of antiaddictive actions of ibogaine. Ann N Y Acad Sci 1998;844:214-26.
  2. Singhal AB, Caviness VS, Begleiter AF, et al. Cerebral vasoconstriction and stroke after use of serotonergic drugs. Neurology 2002;58:130-3. PubMed
  3. Litjens RP, Brunt TM. How toxic is ibogaine? Clin Toxicol (Phila). 2016;54(4):297-302. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction 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.
  • PossibleInteraction 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.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Iboga Also Interacts With Other Medications

Iboga has 1 major, 500 moderate known drug interactions in our database — the Dextromethorphan, Guaifenesin, Pseudoephedrine one above is one of them. If you take anything else, check it against the full list below.

Major 1 Moderate 500 No known interaction 2,329 (incl. Dextromethorphan, Guaifenesin, Pseudoephedrine)
Taking anything else?

Check Another of Your Medications Against Iboga

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

Everything else you take

See Every Supplement That Interacts With Dextromethorphan, Guaifenesin, Pseudoephedrine

This page covers Iboga only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Dextromethorphan, Guaifenesin, Pseudoephedrine page lists 198 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Ephedra (major), Grapefruit (major), Lithium (major) and Peyote (major).

By severity: 8 major · 149 moderate · 41 minor.

Open the Dextromethorphan, Guaifenesin, Pseudoephedrine interaction page

How much people look this up

Where Iboga and Dextromethorphan, Guaifenesin, Pseudoephedrine 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 Iboga
Top half

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

29 days ago today
Medication Dextromethorphan, Guaifenesin, Pseudoephedrine
Steady interest

#2,151 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.

Supplement

About Iboga

What is Iboga?

Iboga
  • Drug and alcohol addiction
  • Opioid withdrawal
  • Spiritual and ceremonial rituals
  • Fatigue and stimulant effects
  • Mood and emotional issues

Iboga is a Central African shrub whose root bark contains ibogaine, a powerful hallucinogenic compound studied mainly for addiction. It carries serious safety risks, including dangerous heart rhythm changes and deaths, and ibogaine is illegal in the United States and many other countries. We do not recommend its use outside of tightly controlled research settings.

Read the full Iboga monograph & all interactions
Keep checking

Other Drugs & Iboga

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

1Major
500Moderate
0Minor
2,328No known interaction
1 Major 500 Moderate 2,328 No interaction
Major

1 interaction

Moderate

500 interactions

Showing 60 of 500 moderate interactions — see all 500 on the Iboga page.

No interaction 2,328 drugs checked — show the list

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

Showing the 60 most looked-up of 2,328 medications checked with no known interaction — see the full Iboga list.

See the full Iboga interactions page
See every supplement checked against Dextromethorphan, Guaifenesin, Pseudoephedrine, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Iboga monograph › Uses, safety, and every drug interaction in one place Dextromethorphan, Guaifenesin, Pseudoephedrine supplement interactions › Every supplement checked against Dextromethorphan, Guaifenesin, Pseudoephedrine, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Iboga and Dextromethorphan, Guaifenesin, Pseudoephedrine Together: Common Questions

Can you take Iboga with Dextromethorphan, Guaifenesin, Pseudoephedrine?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Iboga and Dextromethorphan, Guaifenesin, Pseudoephedrine interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Dextromethorphan, Guaifenesin, Pseudoephedrine and Iboga?

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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.