Drug & supplement interaction

Delta-9-tetrahydrocannabinol (thc) + Acetaminophen, Pseudoephedrine, Triprolidine

Acetaminophen, Pseudoephedrine, Triprolidine brand name: Actifed Plus ES.

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

Delta-9-tetrahydrocannabinol (thc) has a moderate interaction with Acetaminophen, Pseudoephedrine, Triprolidine. Theoretically, THC might decrease the levels and clinical effects of CYP2E1 substrates.

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

Delta-9-tetrahydrocannabinol (thc) and Acetaminophen, Pseudoephedrine, Triprolidine

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

Moderate

CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES

Why this applies to Acetaminophen, Pseudoephedrine, Triprolidine

Acetaminophen, Pseudoephedrine, Triprolidine falls under CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES — the group Delta-9-tetrahydrocannabinol (thc) interacts with.

Theoretically, THC might decrease the levels and clinical effects of CYP2E1 substrates.
In vitro research shows that cannabis containing THC can induce the activity of CYP2E1, which might increase the metabolism of CYP2E1 substrates. It is unclear if this effect is due to THC, other constituents, or the combination.
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

Of the three ingredients in Actifed Plus ES, the one worth talking about here is the acetaminophen (Tylenol) part. A small amount of acetaminophen is handled by a liver enzyme called CYP2E1. Lab studies suggest THC (or something in cannabis) might speed that enzyme up. In theory, a faster CYP2E1 could shift more acetaminophen down the pathway that produces a harmful byproduct, which is the same pathway that matters when people take too much acetaminophen.

I want to be honest: this is only test-tube and animal data, so it's theoretical and not proven in people. The everyday takeaway is simple. Stay within the recommended acetaminophen dose, don't double up on other products that also contain it, and go easy on alcohol. If you use cannabis regularly and take acetaminophen often, check in with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Sheweita, S. A. Narcotic drugs change the expression of cytochrome P450 2E1 and 2C6 and other activities of carcinogen-metabolizing enzymes in the liver of male mice. Toxicology 9-30-2003;191(2-3):133-142. 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

Delta-9-tetrahydrocannabinol (thc) Also Interacts With Other Medications

Delta-9-tetrahydrocannabinol (thc) has 761 moderate, 336 minor known drug interactions in our database — the Acetaminophen, Pseudoephedrine, Triprolidine one above is one of them. If you take anything else, check it against the full list below.

Moderate 761 Minor 336 No known interaction 1,733 (incl. Acetaminophen, Pseudoephedrine, Triprolidine)
Taking anything else?

Check Another of Your Medications Against Delta-9-tetrahydrocannabinol (thc)

Covers the 2,830 medications we’ve checked against Delta-9-tetrahydrocannabinol (thc). Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Acetaminophen, Pseudoephedrine, Triprolidine

This page covers Delta-9-tetrahydrocannabinol (thc) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acetaminophen, Pseudoephedrine, Triprolidine page lists 197 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 Peyote (major).

By severity: 9 major · 149 moderate · 39 minor.

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

“Actifed Plus ES combines acetaminophen, pseudoephedrine, and triprolidine, and the pseudoephedrine is why I would check this page carefully before adding any supplement. Stimulation dominates the list: 44 ingredients, from ephedra to the everyday caffeine in coffee, tea, and cocoa, can stack on the decongestant and push blood pressure…”

Reviewed by 2 · Jul 18, 2026

Open the Acetaminophen, Pseudoephedrine, Triprolidine interaction page

How much people look this up

Where Delta-9-tetrahydrocannabinol (thc) and Acetaminophen, Pseudoephedrine, Triprolidine 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 Delta-9-tetrahydrocannabinol (thc)
Top half

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

29 days ago today
Medication Acetaminophen, Pseudoephedrine, Triprolidine
Steady interest

#1,772 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 Delta-9-tetrahydrocannabinol (thc)

What is Delta-9-tetrahydrocannabinol (thc)?

Delta-9-tetrahydrocannabinol (thc)
  • Chronic or nerve pain
  • Nausea and vomiting from chemotherapy
  • Appetite loss and weight loss
  • Muscle spasticity
  • Sleep problems
  • Anxiety and stress

THC is the main mind-altering compound in cannabis and is best known for causing a 'high.' A prescription form (dronabinol) is approved for chemotherapy-related nausea and appetite loss, but for most other uses the evidence is mixed or limited, and THC can impair thinking and driving. It should be avoided in pregnancy and breastfeeding and used only with medical guidance.

Read the full Delta-9-tetrahydrocannabinol (thc) monograph & all interactions
Keep checking

Other Drugs & Delta-9-tetrahydrocannabinol (thc)

Browse every other medication we’ve checked against Delta-9-tetrahydrocannabinol (thc) — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
761Moderate
336Minor
1,732No known interaction
761 Moderate 336 Minor 1,732 No interaction
Moderate

761 interactions

Showing 60 of 761 moderate interactions — see all 761 on the Delta-9-tetrahydrocannabinol (thc) page.

Minor

336 interactions

Showing 60 of 336 minor interactions — see all 336 on the Delta-9-tetrahydrocannabinol (thc) page.

No interaction 1,732 drugs checked — show the list

We also checked Delta-9-tetrahydrocannabinol (thc) against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 1,732 medications checked with no known interaction — see the full Delta-9-tetrahydrocannabinol (thc) list.

See the full Delta-9-tetrahydrocannabinol (thc) interactions page
See every supplement checked against Acetaminophen, Pseudoephedrine, Triprolidine, 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
Delta-9-tetrahydrocannabinol (thc) monograph › Uses, safety, and every drug interaction in one place Acetaminophen, Pseudoephedrine, Triprolidine supplement interactions › Every supplement checked against Acetaminophen, Pseudoephedrine, Triprolidine, 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 Delta-9-tetrahydrocannabinol (thc) and Acetaminophen, Pseudoephedrine, Triprolidine Together: Common Questions

Can you take Delta-9-tetrahydrocannabinol (thc) with Acetaminophen, Pseudoephedrine, Triprolidine?
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 Delta-9-tetrahydrocannabinol (thc) and Acetaminophen, Pseudoephedrine, Triprolidine 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 Acetaminophen, Pseudoephedrine, Triprolidine and Delta-9-tetrahydrocannabinol (thc)?

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