Drug & supplement interaction

Milk Thistle + Procainamide

Procainamide brand names: Pronestyl, Procanbid, Procan SR, Procan, Pronestyl-SR.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Milk Thistle and Procainamide in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Milk Thistle and Procainamide

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Procainamide and Milk Thistle in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Milk Thistle safety at a glance

Milk Thistle overall Use caution Generally well tolerated in most adults, but quality and effectiveness vary and a doctor should be involved for liver conditions.
Pregnancy Avoid There is not enough reliable safety information, so it is best avoided during pregnancy.
Breastfeeding Use caution Safety during breastfeeding is not well studied, so caution is advised.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Procainamide and Milk Thistle? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Procainamide

Interactions in our licensed database are recorded against drug classes, not just single drug names. Procainamide is filed under 4 classifications — including qt interval-prolonging drugs, anticholinergic drugs, oral drugs. Milk Thistle has documented interactions with 17 drug classes — the most serious being antidiabetes drugs (moderate), cytochrome p450 2b6 (cyp2b6) substrates (moderate) and glucuronidated drugs (moderate) — and none of Procainamide’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Milk Thistle Does Interact With Other Medications

Milk Thistle has 254 moderate, 700 minor known drug interactions in our database — Procainamide isn’t one of them. If you take anything else, check it against the full list below.

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.

What to actually watch for

No Interaction Found — But Data Suggests Milk Thistle and Procainamide May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • Hives Worth acting on Additional detail

    Milk Thistle

    “Orally, milk thistle may cause allergic reactions including urticaria, eczema, skin rash, and anaphylaxis in some people. Allergic reactions may be more likely to occur in patients sensitive to the Asteraceae/Compositae family. A case report describes a 49-year-old female who developed clinical, serologic, and immunopathologic features of bullous pemphigoid after taking milk thistle orally for 6 weeks.”

    Milk Thistle · Natural Medicines adverse-effect record, reported in eczema.

    6 sources cited
    1. 6879. Anon. Milk thistle: Effects on liver disease and cirrhosis and clinical adverse effects. Summary, Evidence Report/Technology Assessment: Number 21, September 2000. Agency for Healthcare Research and Quality, Rockville, MD. Available at: http://www.ahrq.g
    2. 7355. Pares A, Planas R, Torres M, et al. Effects of silymarin in alcoholic patients with cirrhosis of the liver: results of a controlled, double-blind, randomized and multicenter trial. J Hepatol 1998;28:615-21. PubMed
    3. 8956. Boerth J, Strong KM. The clinical utility of milk thistle (Silybum marianum) in cirrhosis of the liver. J Herb Pharmacother 2002;2:11-7.
    4. 63210. El-Kamary, S. S., Shardell, M. D., Abdel-Hamid, M., Ismail, S., El-Ateek, M., Metwally, M., Mikhail, N., Hashem, M., Mousa, A., Aboul-Fotouh, A., El-Kassas, M., Esmat, G., and Strickland, G. T. A randomized controlled trial to assess the safety and effic
    5. 63212. Gharagozloo, M., Moayedi, B., Zakerinia, M., Hamidi, M., Karimi, M., Maracy, M., and Amirghofran, Z. Combined therapy of silymarin and desferrioxamine in patients with beta-thalassemia major: a randomized double-blind clinical trial. Fundam.Clin.Pharmaco
    6. 63238. Ramirez-Santos, A., Perez-Bustillo, A., Gonzalez-Sixto, B., Suarez-Amor, O., and Rodriguez-Prieto, M. A. [Acute generalized exanthematous pustulosis due to milk thistle (Silybum marianum) tea]. Actas Dermosifiliogr. 2011;102(9):744-745. DOI

    Procainamide

    Listed in the ADVERSE REACTIONS section of the FDA label for Procainamide. Read the label on DailyMed ›

  • A change in taste / Reduced appetite / Stomach pain / Vomiting Additional detail

    Milk Thistle

    “Mild gastrointestinal symptoms have been reported, including nausea, vomiting, bloating, diarrhea, epigastric pain, abdominal colic or discomfort, dyspepsia, dysgeusia, flatulence, constipation, and loss of appetite. There is one report of a 57-year-old female with sweating, nausea, colicky abdominal pain, diarrhea, vomiting, weakness, and collapse after ingesting milk thistle;”

    Milk Thistle · Natural Medicines adverse-effect record, reported in constipation.

    6 sources cited
    1. 2616. Ferenci P, Dragosics B, Dittrich H, et al. Randomized controlled trial of silymarin treatment in patients with cirrhosis of the liver. J Hepatol 1989;9:105-13. PubMed
    2. 6879. Anon. Milk thistle: Effects on liver disease and cirrhosis and clinical adverse effects. Summary, Evidence Report/Technology Assessment: Number 21, September 2000. Agency for Healthcare Research and Quality, Rockville, MD. Available at: http://www.ahrq.g
    3. 8956. Boerth J, Strong KM. The clinical utility of milk thistle (Silybum marianum) in cirrhosis of the liver. J Herb Pharmacother 2002;2:11-7.
    4. 13170. Tanamly MD, Tadros F, Labeeb S, et al. Randomised double-blinded trial evaluating silymarin for chronic hepatitis C in an Egyptian village: study description and 12-month results. Dig Liver Dis 2004;36:752-9. PubMed
    5. 63140. Allain, H., Schuck, S., Lebreton, S., Strenge-Hesse, A., Braun, W., Gandon, J. M., and Brissot, P. Aminotransferase levels and silymarin in de novo tacrine-treated patients with Alzheimer's disease. Dement.Geriatr.Cogn Disord. 1999;10(3):181-185. PubMed
    6. 63146. Angulo, P., Patel, T., Jorgensen, R. A., Therneau, T. M., and Lindor, K. D. Silymarin in the treatment of patients with primary biliary cirrhosis with a suboptimal response to ursodeoxycholic acid. Hepatology 2000;32(5):897-900. PubMed

    Procainamide

    Listed in the ADVERSE REACTIONS section of the FDA label for Procainamide. Read the label on DailyMed ›

  • Dizziness Additional detail

    Milk Thistle

    “With oral milk thistle use, CNS symptoms have been reported, including headache, dizziness, and sleep disturbances.”

    Milk Thistle · Natural Medicines adverse-effect record, reported in cluster headache.

    2 sources cited
    1. 114913. Rustamzadeh A, Sadigh N, Vahabi Z, et al. Effects silymarin and rosuvastatin on amyloid-carriers level in dyslipidemic Alzheimer's patients: A double-blind placebo-controlled randomized clinical trial. IBRO Neurosci Rep 2024;17:108-121. PubMed
    2. 114914. Fatemi Shandiz A, Karimi G, Dayyani M, Hosseini S, Elyasi S. Evaluation of oral silymarin formulation efficacy in prevention of doxorubicin induced hepatotoxicity in patients with non-metastatic breast cancer. J Oncol Pharm Pract 2024. PubMed

    Procainamide

    Listed in the ADVERSE REACTIONS section of the FDA label for Procainamide. Read the label on DailyMed ›

  • Diarrhea / Nausea Additional detail

    Milk Thistle

    “Orally, milk thistle is well tolerated.

    Most Common Adverse Effects:

    Orally: Abdominal bloating, diarrhea, dyspepsia, flatulence, and nausea. However, these adverse effects do not typically occur at a greater frequency than with placebo.

    Serious Adverse Effects (Rare):

    Orally: Allergic reactions, including anaphylaxis, have been reported.”

    Milk Thistle · Natural Medicines adverse-effect record, reported in diarrhea.

    Procainamide

    Listed in the ADVERSE REACTIONS section of the FDA label for Procainamide. Read the label on DailyMed ›

  • A skin rash Additional detail

    Milk Thistle

    Recorded for Milk Thistle in the same Natural Medicines adverse-effect record shown under Hives above.

    Procainamide

    Listed in the ADVERSE REACTIONS section of the FDA label for Procainamide. Read the label on DailyMed ›

Reported for Milk Thistle but not commonly for Procainamide: trouble sleeping, an allergic reaction, constipation and a severe allergic reaction.

Effects for Procainamide come from the ADVERSE REACTIONS section of its FDA label; effects for Milk Thistle come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

From our Q&A

Questions About Milk Thistle or Procainamide

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 Procainamide, 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 Procainamide

This page covers Milk Thistle only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Procainamide page lists 59 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Cesium (major) and Ephedra (major).

By severity: 9 major · 39 moderate · 11 minor.

From our pharmacist’s overview on the Procainamide page

“Procainamide treats serious heart rhythm problems, and anything that nudges the heart's electrical timing further can turn a helpful drug into a hazard, so I would give this list genuine care. Nine of the 59 supplements on file carry a major rating, and the 13 QT prolongers are the ones to understand first.”

Reviewed by 2 · Jul 18, 2026

Open the Procainamide 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. Even though Milk Thistle itself has no known interaction with Procainamide, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Milk Thistle and Procainamide 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%

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

29 days ago today
Medication Procainamide
Top 10%

#242 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Milk Thistle reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Milk Thistle and Procainamide records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
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.

Silybum marianum · Asteraceae · Seeds (fruit) · Capsules, tablets, softgels, liquid extracts, tinctures, tea

An interaction check asks whether these two react with each other — it does not ask whether Milk Thistle is a good idea for someone in your situation. Here is what our Milk Thistle record says about it on its own.

Milk Thistle: dosing

There is no single official or proven dose for milk thistle. Studies have used a wide range of amounts, and products differ in how much silymarin they contain, which makes comparing doses difficult.The best approach is to follow the directions on the product label and choose a reputable brand. Look for products that list a standardized silymarin content.

From our Milk Thistle monograph — the full record covers uses, side effects and every documented interaction.

Read the full Milk Thistle monograph & all interactions
Medication

About Procainamide

What Is Procainamide Used For?

Brand names: Pronestyl, Procanbid, Procan SR, Procan, Pronestyl-SR

Procainamide hydrochloride injection is used to treat documented, life-threatening ventricular arrhythmias — most notably sustained ventricular tachycardia (a dangerously fast heart rhythm originating in the lower chambers of the heart). Because of its serious risk profile, it is reserved for situations where the benefit clearly outweighs the risk.

Procainamide is not recommended for minor or asymptomatic arrhythmias, and treatment should always be started in a hospital setting where close monitoring is possible. Antiarrhythmic drugs, including procainamide, have not been shown to improve survival in patients with arrhythmias that are not life-threatening.

See full Procainamide 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
254Moderate
700Minor
1,875No known interaction
Moderate

254 interactions

Showing 60 of 254 moderate interactions — see all 254 on the Milk Thistle page.

Minor

700 interactions

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

No interaction 1,875 drugs checked — show the list
Evidence & sources

Milk Thistle References

The 69 references that drive our Milk Thistle monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Ferenci P, Dragosics B, Dittrich H, et al. Randomized controlled trial of silymarin treatment in patients with cirrhosis of the liver. J Hepatol 1989;9:105-13. PubMed
  2. Anon. Milk thistle: Effects on liver disease and cirrhosis and clinical adverse effects. Summary, Evidence Report/Technology Assessment: Number 21, September 2000. Agency for Healthcare Research and Quality, Rockville, MD. Available at: http://www.ahrq.g
  3. Beckmann-Knopp S, Rietbrock S, Weyhenmeyer R, et al. Inhibitory effects of silibinin on cytochrome P-450 enzymes in human liver microsomes. Pharmacol Toxicol 2000;86:250-6. PubMed
  4. 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
  5. 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
  6. Pares A, Planas R, Torres M, et al. Effects of silymarin in alcoholic patients with cirrhosis of the liver: results of a controlled, double-blind, randomized and multicenter trial. J Hepatol 1998;28:615-21. PubMed
  7. 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
  8. Boerth J, Strong KM. The clinical utility of milk thistle (Silybum marianum) in cirrhosis of the liver. J Herb Pharmacother 2002;2:11-7.
  9. Tanamly MD, Tadros F, Labeeb S, et al. Randomised double-blinded trial evaluating silymarin for chronic hepatitis C in an Egyptian village: study description and 12-month results. Dig Liver Dis 2004;36:752-9. PubMed
  10. Gurley BJ, Gardner SF, Hubbard MA, et al. In vivo assessment of botanical supplementation on human cytochrome P450 phenotypes: Citrus aurantium, Echinacea purpurea, milk thistle, and saw palmetto. Clin Pharmacol Ther 2004;76:428-40. .
  11. Huseini HF, Larijani B, Heshmat R, et al. The efficacy of Silybum marianum (L.) Gaertn. (silymarin) in the treatment of type II diabetes: a randomized, double-blind, placebo-controlled, clinical trial. Phytother Res 2006;20;1036-9.
  12. Deng JW, Shon JH, Shin HJ, et al. Effect of silymarin supplement on the pharmacokinetics of rosuvastatin. Pharm Res 2008;25:1807-14. PubMed
  13. Kim CS, Choi SJ, Park CY, et al. Effects of silybinin on the pharmacokinetics of tamoxifen and its active metabolite, 4-hydroxytamoxifen in rats. Anticancer Res 2010;30:79-85.
  14. 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
  15. 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.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Milk Thistle and Procainamide Together: Common Questions

Is it safe to take Milk Thistle with Procainamide?
We do not list a known interaction between Milk Thistle and Procainamide. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Milk Thistle and Procainamide have any of the same side effects?
Yes — our sources link each of them separately to 9 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the Milk Thistle and Procainamide combination checked?
Interactions in our licensed database are recorded against drug classes. Procainamide is filed under 4 classifications, and Milk Thistle has documented interactions with 17 drug classes — none of Procainamide's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Milk Thistle interact with any other medications?
Yes. Milk Thistle has 954 documented drug interactions in our database — Procainamide is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Procainamide interact with any supplements?
Yes. Procainamide has documented interactions with 59 supplements in our database — Milk Thistle is not one of them. The Procainamide interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Procainamide 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.