Drug & supplement interaction

Delta-9-tetrahydrocannabinol (thc) + Rifapentine

Rifapentine brand name: Priftin.

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

Rifapentine falls into 2 drug categories that Delta-9-tetrahydrocannabinol (thc) can interact with; the most serious is rated moderate. Theoretically, CYP3A4 inducers might reduce the levels and clinical effects of THC.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Delta-9-tetrahydrocannabinol (thc) and Rifapentine

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Delta-9-tetrahydrocannabinol (thc) interacts with whole categories of medication. Rifapentine falls into 2 of those categories, so it can interact with Delta-9-tetrahydrocannabinol (thc) in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 3A4 (CYP3A4) INDUCERS

1 of 2

Why this applies to Rifapentine

Rifapentine falls under CYTOCHROME P450 3A4 (CYP3A4) INDUCERS — the group Delta-9-tetrahydrocannabinol (thc) interacts with.

Theoretically, CYP3A4 inducers might reduce the levels and clinical effects of THC.
THC is a substrate of CYP3A4 enzymes.
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 gist: rifapentine (Priftin) is a strong 'enzyme booster.' It revs up a liver pathway called CYP3A4, which happens to be one of the systems that breaks down THC. So if you're using cannabis or a THC product while taking rifapentine, your body may clear the THC faster than usual. In plain terms, that high or the relief you're looking for could feel weaker or shorter-lasting.

Keep in mind this is mostly a theoretical interaction based on how these substances behave, not on solid human studies, so it shouldn't alarm you. The bigger priority is taking your rifapentine exactly as prescribed so your TB treatment works. If you use THC for any reason, just mention it to your pharmacist or doctor so they can keep an eye on things.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Product information for Marinol. AbbVie. North Chicago, IL 60064. August 2017. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/018651s029lbl.pdf.
Moderate

CYTOCHROME P450 2C9 (CYP2C9) INDUCERS

2 of 2

Rifapentine also falls under CYTOCHROME P450 2C9 (CYP2C9) INDUCERS.

Theoretically, drugs that are CYP2C9 inducers might decrease the levels and clinical effects of THC.
THC is a substrate of CYP2C9 enzymes.
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 gist if you use cannabis or THC products while you're on rifapentine (Priftin) for TB. Rifapentine is a strong revver of the liver's drug-processing enzymes, including one called CYP2C9 that helps break down THC. By speeding that enzyme up, rifapentine could clear THC out of your system faster, so the THC may feel weaker or wear off sooner than you'd expect.

I want to be straight with you: this is a theoretical interaction, based on how these two work on paper rather than on real patient studies. It doesn't make rifapentine itself less effective at treating your TB, and it isn't dangerous. The bigger point is to take your TB medicine exactly as directed and finish the full course. If you use cannabis, just mention it to your pharmacist or doctor so they have the full picture.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Product information for Marinol. AbbVie. North Chicago, IL 60064. August 2017. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/018651s029lbl.pdf.

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 Rifapentine one above is among them. If you take anything else, check it against the full list below.

Moderate 761 Minor 336 No known interaction 1,733 (incl. Rifapentine)
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 Rifapentine

This page covers Delta-9-tetrahydrocannabinol (thc) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Rifapentine page lists 64 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Alkanna (moderate), Alpine Ragwort (moderate), Bacillus Coagulans (moderate) and Bacillus Subtilis (moderate).

By severity: 1 major · 53 moderate · 10 minor.

From our pharmacist’s overview on the Rifapentine page

“Rifapentine (Priftin) treats tuberculosis and is often dosed just once or twice a week, so a single blunted dose costs more than it would with a daily pill. That is why I read this list of 64 interacting supplements as a real warning rather than routine fine print.”

Reviewed by 2 · Jul 18, 2026

Open the Rifapentine interaction page

How much people look this up

Where Delta-9-tetrahydrocannabinol (thc) and Rifapentine 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

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

29 days ago today
Medication Rifapentine
Top half

#900 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
Medication

About Rifapentine

What Is Rifapentine Used For?

Brand name: Priftin

Rifapentine (brand name Priftin) is used to treat two forms of tuberculosis (TB) caused by Mycobacterium tuberculosis. For active pulmonary TB — an active infection in the lungs — it is approved for patients 12 years and older, always used alongside other TB medicines, never alone. For latent TB infection (LTBI) — where the bacteria are in the body but not causing active illness — it is approved for patients 2 years and older who are at high risk of the infection becoming active, always combined with isoniazid.

Priftin is not appropriate for every TB situation. It should not be used alone at any stage of active TB treatment, and it is not recommended as a once-weekly continuation regimen combined with isoniazid in people living with HIV who have active pulmonary TB, due to a higher risk of treatment failure or relapse.

See full Rifapentine drug information
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 Rifapentine, 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 Rifapentine supplement interactions › Every supplement checked against Rifapentine, ranked by severity Rifapentine drug information › The full plain-English guide to this medication 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 Rifapentine Together: Common Questions

Can you take Delta-9-tetrahydrocannabinol (thc) with Rifapentine?
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 2 interactions listed for Delta-9-tetrahydrocannabinol (thc) and Rifapentine?
Rifapentine belongs to more than one drug category, and Delta-9-tetrahydrocannabinol (thc) 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 Delta-9-tetrahydrocannabinol (thc) and Rifapentine 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.