Drug & supplement interaction

Iboga + Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine

Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine brand names: Tylenol Cold Ex Strength, Children's Tylenol Cold Plus Cough.

Moderate Interaction
The bottom line Moderate

Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine falls into 3 drug categories that Iboga can interact with; the most serious is rated moderate. 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
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Iboga and Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Iboga interacts with whole categories of medication. Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine falls into 3 of those categories, so it can interact with Iboga in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

SEROTONERGIC DRUGS

1 of 3

Why this applies to Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine

Acetaminophen, Chlorpheniramine, Dextromethorphan, 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

In this cold-and-cough combo, the ingredient I'd zero in on is dextromethorphan (the cough suppressant). It nudges serotonin levels up, and Iboga (through its main compound, ibogaine) does the same thing. Stack the two and you could get an additive serotonin effect. In rare cases that can build toward serotonin syndrome, with symptoms like agitation, a racing heart, sweating, shivering, muscle twitching, or confusion.

I'll be honest: this concern is theoretical, based on how these substances work rather than real-world reports, so don't panic. That said, Iboga carries serious heart-rhythm risks of its own and is illegal in the U.S. We don't recommend using it. Please run any combination past your pharmacist or doctor first.

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
Moderate

ANTICHOLINERGIC DRUGS

2 of 3

Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine also falls under ANTICHOLINERGIC DRUGS.

Theoretically, iboga might decrease the effectiveness of anticholinergic drugs.
In vitro research shows that iboga can inhibit acetylcholinesterase and might increase acetylcholine levels. However, the constituent ibogaine does not appear to have this effect.
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 for this combo product: it contains chlorpheniramine, an antihistamine with anticholinergic (drying) effects. Lab studies suggest Iboga may raise acetylcholine levels, which is the opposite of what chlorpheniramine does. In theory, that could blunt some of the antihistamine's action, so you might notice your runny nose or sneezing isn't quite as controlled. The rest of the ingredients (acetaminophen for pain/fever, dextromethorphan for cough, pseudoephedrine for congestion) aren't really the focus here.

I'll be honest with you: this is theoretical, based only on test-tube research, and the main Iboga compound (ibogaine) didn't show this effect. Frankly, Iboga's serious heart and safety risks are the far bigger concern. Please talk with your pharmacist before mixing them.

References
  1. Alper K, Reith ME, Sershen H. Ibogaine and the inhibition of acetylcholinesterase. J Ethnopharmacol. 2012;139(3):879-82. PubMed
Moderate

CYTOCHROME P450 2D6 (CYP2D6) INHIBITORS

3 of 3

Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine also falls under CYTOCHROME P450 2D6 (CYP2D6) INHIBITORS.

Theoretically, taking iboga with CYP2D6 inhibitors might increase the levels and clinical effects of ibogaine.
Ibogaine, the active constituent of iboga, is a substrate of CYP2D6. One pharmacokinetic study shows that taking the CYP2D6 inhibitor paroxetine prior to taking ibogaine 20 mg increases the exposure to ibogaine and its metabolite noribogaine by 2-fold when compared with ibogaine alone.
Severity Moderate Likelihood Possible Evidence B

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 key thing with this combo: one ingredient in your cold medicine, dextromethorphan (the cough suppressant), is broken down by the same liver enzyme, CYP2D6, that handles ibogaine from Iboga. Dextromethorphan is actually a known blocker of that enzyme. So in theory, taking it alongside Iboga could slow down how fast ibogaine clears, letting ibogaine and its byproduct build up to higher levels (a study with another CYP2D6 blocker showed roughly a doubling). That matters because ibogaine itself carries real dangers, including serious heart rhythm changes.

This is mostly theoretical, and honestly the bigger concern is Iboga's own risks. Ibogaine is illegal in the U.S. and not something we recommend. Please talk with your pharmacist before mixing these, and don't change any medication on your own.

References
  1. Henstra M, Wong L, Chahbouni A, et al. Toxicokinetics of ibogaine and noribogaine in a patient with prolonged multiple cardiac arrhythmias after ingestion of internet purchased ibogaine. Clin Toxicol (Phila). 2017;55(6):600-602. PubMed
  2. Glue P, Winter H, Garbe K, et al. Influence of CYP2D6 activity on the pharmacokinetics and pharmacodynamics of a single 20?mg dose of ibogaine in healthy volunteers. J Clin Pharmacol. 2015;55(6):680-7. PubMed
  3. Rodriguez P, Urbanavicius J, Prieto JP, et al. A single administration of the atypical psychedelic ibogaine or its metabolite noribogaine induces an antidepressant-like effect in rats. ACS Chem Neurosci 2020;11(11):1661-1672. 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 Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine one above is among them. If you take anything else, check it against the full list below.

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 Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine

This page covers Iboga only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine page lists 301 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 14 major · 242 moderate · 45 minor.

From our pharmacist’s overview on the Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine page

“Because Tylenol Cold Extra Strength packs four drugs into one dose (acetaminophen, chlorpheniramine, dextromethorphan, and pseudoephedrine), its supplement list runs to 301 ingredients, and 14 carry a major rating, so I'd approach this one with real care. The biggest hazards mirror the drugs themselves.”

Reviewed by 2 · Jul 18, 2026

Open the Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine interaction page

How much people look this up

Where Iboga and Acetaminophen, Chlorpheniramine, Dextromethorphan, 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

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

29 days ago today
Medication Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine
Top 10%

#220 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
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
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

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Pharmacist Counseling Corner

Taking Iboga and Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine Together: Common Questions

Can you take Iboga with Acetaminophen, Chlorpheniramine, Dextromethorphan, 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.
Why are there 3 interactions listed for Iboga and Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine?
Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine belongs to more than one drug category, and Iboga interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Iboga and Acetaminophen, Chlorpheniramine, Dextromethorphan, 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

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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.