Drug & supplement interaction

Milk Thistle + Buproprion, Dextromethorphan

Buproprion, Dextromethorphan brand name: Auvelity.

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

Buproprion, Dextromethorphan falls into 2 drug categories that Milk Thistle can interact with; the most serious is rated moderate. Theoretically, milk thistle might inhibit CYP2B6.

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

Milk Thistle and Buproprion, Dextromethorphan

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

Why Are There 2 Interactions?

Milk Thistle interacts with whole categories of medication. Buproprion, Dextromethorphan falls into 2 of those categories, so it can interact with Milk Thistle 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 2B6 (CYP2B6) SUBSTRATES

1 of 2

Why this applies to Buproprion, Dextromethorphan

Buproprion, Dextromethorphan falls under CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES — the group Milk Thistle interacts with.

Theoretically, milk thistle might inhibit CYP2B6.
An in vitro study shows that silybin, a constituent of milk thistle, binds to and noncompetitively inhibits CYP2B6. Additionally, silybin might downregulate the expression of CYP2B6 by decreasing mRNA and protein levels.
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

Auvelity combines bupropion and dextromethorphan, and the bupropion piece relies on an enzyme called CYP2B6 to be processed. Here's the wrinkle: bupropion is actually changed by that enzyme into an active form (hydroxybupropion) that does a lot of the work. Milk thistle's silybin has been shown, in test-tube studies only, to block CYP2B6. If that happened in the body, it could shift how much active drug forms and how much parent bupropion lingers.

What this means in real life is uncertain. The evidence here is lab-dish data, not human studies, so I wouldn't lose sleep over it. Still, since bupropion can cause jitteriness, insomnia, or (rarely) seizures, it's worth a quick chat with your pharmacist or doctor before adding concentrated milk thistle.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Zhang W, Zhang Y, Wen C, Jiang X, Wang L. In vitro Assessment of the Effects of Silybin on CYP2B6-mediated Metabolism. Planta Med 2023. PubMed
Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

Buproprion, Dextromethorphan also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

It is unclear if milk thistle inhibits CYP3A4; research is conflicting.
While laboratory research shows conflicting results, pharmacokinetic research shows that taking milk thistle extract 420-1350 mg daily does not significantly affect the metabolism of the CYP3A4 substrates irinotecan, midazolam, or indinavir. However, 8 case reports from the World Health Organization (WHO) adverse drug reaction database describe increased toxicity in patients taking milk thistle and cancer medications that are CYP3A4 substrates, including gefitinib, sorafenib, doxorubicin, and vincristine.
Severity Minor Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

Auvelity combines dextromethorphan and bupropion. The bupropion piece is there partly to slow down how fast your body clears the dextromethorphan, which helps it work. Here, the question is whether milk thistle blocks the CYP3A4 enzyme. The honest answer is that the science is muddy. Careful human studies found milk thistle did not meaningfully change CYP3A4-handled drugs, so any real effect on Auvelity is unlikely.

If milk thistle did slightly slow this pathway, you might notice a touch more dizziness, dry mouth, jitteriness, or trouble sleeping. That said, this is mostly theoretical, and rated minor. Still, it never hurts to run your supplement list past your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Venkataramanan R, Ramachandran V, Komoroski BJ, et al. Milk thistle, a herbal supplement, decreases the activity of CYP3A4 and uridine diphosphoglucuronosyl transferase in human hepatocyte cultures. Drug Metab Dispos 2000;28:1270-3. DOI
  2. Piscitelli SC, Formentini E, Burstein AH, et al. Effect of milk thistle on the pharmacokinetics of indinavir in healthy volunteers. Pharmacotherapy 2002;22:551-6. PubMed
  3. Sridar C, Goosen TC, Kent UM, et al. Silybin inactivates cytochromes P450 3A4 and 2C9 and inhibits major hepatic glucuronosyltransferases. Drug Metab Dispos 2004;32:587-94. PubMed
  4. van Erp NP, Baker SD, Zhao M, et al. Effect of milk thistle (Silybum marianum) on the pharmacokinetics of irinotecan. Clin Cancer Res 2005;11:7800-6.
  5. Budzinski JW, Trudeau VL, Drouin CE, et al. Modulation of human cytochrome P450 3A4 (CYP3A4) and P-glycoprotein (P-gp) in Caco-2 cell monolayers by selected commercial-source milk thistle and goldenseal products. Can J Physiol Pharmacol 2007;85:966-78.
  6. Doehmer J, Weiss G, McGregor GP, Appel K. Assessment of a dry extract from milk thistle (Silybum marianum) for interference with human liver cytochrome-P450 activities. Toxicol In Vitro 2011;25:21-7. PubMed
  7. Jalloh MA, Gregory PJ, Hein D, et al. Dietary supplement interactions with antiretrovirals: a systematic review. Int J STD AIDS. 2017 Jan;28(1):4-15. PubMed
  8. Kawaguchi-Suzuki M, Frye RF, Zhu HJ, et al. The effects of milk thistle (Silybum marianum) on human cytochrome P450 activity. Drug Metab Dispos. 2014;42(10):1611-6. PubMed
  9. Pochet S, Lechon AS, Lescrainier C, et al. Herb-anticancer drug interactions in real life based on VigiBase, the WHO global database. Sci Rep 2022;12(1):14178. 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

Milk Thistle Also Interacts With Other Medications

Milk Thistle has 253 moderate, 700 minor known drug interactions in our database — the Buproprion, Dextromethorphan one above is among them. If you take anything else, check it against the full list below.

Moderate 253 Minor 700 No known interaction 1,877 (incl. Buproprion, Dextromethorphan)
Taking anything else?

Check Another of Your Medications Against Milk Thistle

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

From our Q&A

Questions About Milk Thistle or Buproprion, Dextromethorphan

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Milk Thistle or Buproprion, Dextromethorphan, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Buproprion, Dextromethorphan

This page covers Milk Thistle only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Buproprion, Dextromethorphan page lists 178 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), Lithium (major), St. John's Wort (major) and 1,3-dmaa (moderate).

By severity: 4 major · 134 moderate · 40 minor.

From our pharmacist’s overview on the Buproprion, Dextromethorphan page

“Auvelity pairs dextromethorphan with bupropion to treat depression, and its interaction list is one to approach carefully, with 178 supplements on file and four of them rated major. St.”

Reviewed by 2 · Jul 18, 2026

Open the Buproprion, Dextromethorphan interaction page

One more smart check

Taking Milk Thistle as Part of a Dietary Supplement Product? Check It for Interactions

We hold 4,560 real supplement products containing Milk Thistle, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Milk Thistle. Your product may carry other ingredients that interact with Buproprion, Dextromethorphan too, on top of Milk Thistle — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Milk Thistle and Buproprion, Dextromethorphan 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 Milk Thistle
Top 5%

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

29 days ago today
Medication Buproprion, Dextromethorphan
Steady interest

#1,871 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 Milk Thistle

What is Milk Thistle?

Milk Thistle
  • Liver health and protection
  • Hepatitis
  • Cirrhosis
  • Gallbladder problems
  • High cholesterol
  • Type 2 diabetes support

Milk thistle is a popular herbal supplement most often used for liver health, and its main active component is a group of compounds called silymarin. While it is generally well tolerated, the scientific evidence that it meaningfully improves liver disease or other conditions is mixed and far from conclusive. Talk with your pharmacist or doctor before using it, especially if you have a liver condition or take other medicines.

Read the full Milk Thistle monograph & all interactions
Medication

About Dextromethorphan and Bupropion

What Is Dextromethorphan and Bupropion Used For?

Brand name: Auvelity

Auvelity (dextromethorphan/bupropion) is approved to treat major depressive disorder (MDD) in adults. It is also approved to treat agitation associated with dementia due to Alzheimer's disease in adults.

For Alzheimer's-related agitation, Auvelity is not meant to be taken only when agitation flares up — it is a scheduled, ongoing treatment, not an as-needed medication.

See full Dextromethorphan and Bupropion drug information
Keep checking

Other Drugs & Milk Thistle

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

0Major
253Moderate
700Minor
1,876No known interaction
253 Moderate 700 Minor 1,876 No interaction
Moderate

253 interactions

Showing 60 of 253 moderate interactions — see all 253 on the Milk Thistle page.

Minor

700 interactions

Showing 60 of 700 minor interactions — see all 700 on the Milk Thistle page.

No interaction 1,876 drugs checked — show the list

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

Showing the 60 most looked-up of 1,876 medications checked with no known interaction — see the full Milk Thistle list.

See the full Milk Thistle interactions page
See every supplement checked against Buproprion, Dextromethorphan, 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
Milk Thistle monograph › Uses, safety, and every drug interaction in one place Buproprion, Dextromethorphan supplement interactions › Every supplement checked against Buproprion, Dextromethorphan, ranked by severity Dextromethorphan and Bupropion 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 Milk Thistle and Buproprion, Dextromethorphan Together: Common Questions

Can you take Milk Thistle with Buproprion, Dextromethorphan?
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 Milk Thistle and Buproprion, Dextromethorphan?
Buproprion, Dextromethorphan belongs to more than one drug category, and Milk Thistle 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 Milk Thistle and Buproprion, Dextromethorphan 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.