Drug & supplement interaction

Milk Thistle + Apomorphine

Apomorphine brand names: Uprima, Apokyn, APO-go, APO-go Pen, APO-go PFS.

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

Apomorphine falls into 2 drug categories that Milk Thistle can interact with; the most serious is rated moderate. Theoretically, milk thistle might affect the clearance of drugs that undergo glucuronidation.

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

Milk Thistle and Apomorphine

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. Apomorphine 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

GLUCURONIDATED DRUGS

1 of 2

Why this applies to Apomorphine

Apomorphine falls under GLUCURONIDATED DRUGS — the group Milk Thistle interacts with.

Theoretically, milk thistle might affect the clearance of drugs that undergo glucuronidation.
Laboratory research shows that milk thistle constituents inhibit uridine diphosphoglucuronosyl transferase (UGT), the major phase 2 enzyme that is responsible for glucuronidation. Theoretically, this could decrease the clearance and increase levels of glucuronidated drugs. Other laboratory research suggests that a milk thistle extract of silymarin might inhibit beta-glucuronidase, although the significance of this effect is unclear.
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 for your apomorphine (Apokyn). Your body partly clears this medicine by attaching a sugar molecule to it, a process called glucuronidation that's handled by an enzyme called UGT. In test-tube studies, milk thistle's active compounds (silymarin) appear to slow that enzyme down. In theory, that could let apomorphine clear a little more slowly and build up slightly, which might mean stronger effects, more nausea or vomiting, sleepiness, dizziness, or low blood pressure when you stand.

I want to be honest with you though: this is based only on lab work, not on real people taking both together, so it's a possible concern rather than a proven one. Since apomorphine already causes nausea and blood pressure drops, it's worth a quick chat with your doctor or pharmacist before adding milk thistle. Don't change anything on your own.

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. Kim DH, Jin YH, Park JB, Kobashi K. Silymarin and its components are inhibitors of beta-glucuronidase. Biol Pharm Bull 1994;17:443-5. 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
Minor

P-GLYCOPROTEIN SUBSTRATES

2 of 2

Apomorphine also falls under P-GLYCOPROTEIN SUBSTRATES.

Theoretically, milk thistle might increase the absorption of P-glycoprotein substrates. However, this effect does not seem to be clinically significant.
In vitro research shows that milk thistle can inhibit P-glycoprotein activity and 1 case report from the World Health Organization (WHO) adverse drug reaction database describes increased abdominal pain in a patient taking milk thistle and the cancer medication vincristine, a P-glycoprotein substrate, though this patient was also taking methotrexate. However, a small pharmacokinetic study in healthy volunteers shows that taking milk thistle (Enzymatic Therapy Inc.) 900 mg, standardized to 80% silymarin, in 3 divided doses daily for 14 days does not affect absorption of digoxin, a P-glycoprotein substrate.
Severity Minor Likelihood Unlikely Evidence B

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

Here's the short version: this combination is very low on the worry list. Milk thistle's active part, silymarin, can mildly block a transporter called P-glycoprotein in lab studies. Apomorphine is carried by that same transporter, so in theory milk thistle could let a little more apomorphine into your system. In real life, though, this effect looks too small to matter.

The evidence backing any real-world problem is thin and mostly theoretical. If anything did happen, you might notice slightly stronger apomorphine effects like nausea, yawning, dizziness, lightheadedness when standing, or drowsiness. That's unlikely. Still, since apomorphine is a potent medicine for Parkinson's off episodes, it's worth mentioning milk thistle to your pharmacist or neurologist before you start it.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Gurley, B. J., Barone, G. W., Williams, D. K., Carrier, J., Breen, P., Yates, C. R., Song, P. F., Hubbard, M. A., Tong, Y., and Cheboyina, S. Effect of milk thistle (Silybum marianum) and black cohosh (Cimicifuga racemosa) supplementation on digoxin phar
  2. Derosa G, Romano D, D'Angelo A, Maffioli P. Berberis aristata/Silybum marianum fixed combination (Berberol(®)) effects on lipid profile in dyslipidemic patients intolerant to statins at high dosages: a randomized, placebo-controlled, clinical trial. Phyto PubMed
  3. 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 Apomorphine 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. Apomorphine)
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 Apomorphine

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 Apomorphine, 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 Apomorphine

This page covers Milk Thistle only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Apomorphine page lists 67 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), St. John's Wort (major), Ayahuasca (moderate), Bitter Melon (moderate) and Black Horehound (moderate).

By severity: 2 major · 49 moderate · 16 minor.

From our pharmacist’s overview on the Apomorphine page

“Apomorphine is often used as a rescue treatment for sudden "off" episodes in Parkinson's disease, which makes a reliable dose worth protecting, and this is a list to read with real care rather than skim. Of the 67 supplements and herbs on file, two carry a major rating: St.”

Reviewed by 2 · Jul 18, 2026

Open the Apomorphine 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 Apomorphine 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 Apomorphine 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%

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

29 days ago today
Medication Apomorphine
Top half

#920 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 Apomorphine Injection

What Is Apomorphine Injection Used For?

Brand names: Uprima, Apokyn, APO-go, APO-go Pen, APO-go PFS

Apomorphine Injection treats “off” episodes in advanced Parkinson's disease. These are periods of poor movement and stiffness, sometimes called hypomobility. They include “end-of-dose wearing off” and unpredictable “on/off” episodes.

It is used for acute, intermittent treatment, meaning as-needed treatment of episodes as they happen. It has been studied as an add-on to other Parkinson's medicines.

See full Apomorphine Injection 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 Apomorphine, 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 Apomorphine supplement interactions › Every supplement checked against Apomorphine, ranked by severity Apomorphine Injection 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 Apomorphine Together: Common Questions

Can you take Milk Thistle with Apomorphine?
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 Apomorphine?
Apomorphine 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 Apomorphine 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 Apomorphine and Milk Thistle?

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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.