Drug & supplement interaction

Manchurian Thorn + Tolcapone

Tolcapone brand name: Tasmar.

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

Manchurian Thorn has a moderate interaction with Tolcapone. Animal research suggests that high doses of Manchurian thorn can induce liver damage.

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

Manchurian Thorn and Tolcapone

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

Moderate

HEPATOTOXIC DRUGS

Why this applies to Tolcapone

Tolcapone falls under HEPATOTOXIC DRUGS — the group Manchurian Thorn interacts with.

Animal research suggests that high doses of Manchurian thorn can induce liver damage. Theoretically, concomitant use with other potentially hepatotoxic drugs might increase the risk of developing liver damage.
Some of these drugs include acarbose (Precose, Prandase), amiodarone (Cordarone), atorvastatin (Lipitor), azathioprine (Imuran), carbamazepine (Tegretol), cerivastatin (Baycol), diclofenac (Voltaren), felbamate (Felbatol), fenofibrate (Tricor), fluvastatin (Lescol), gemfibrozil (Lopid), isoniazid, itraconazole, (Sporanox), ketoconazole (Nizoral), leflunomide (Arava), lovastatin (Mevacor), methotrexate (Rheumatrex), nevirapine (Viramune), niacin, nitrofurantoin (Macrodantin), pioglitazone (Actos), pravastatin (Pravachol), pyrazinamide, rifampin (Rifadin), ritonavir (Norvir), rosiglitazone (Avandia), simvastatin (Zocor), tacrine (Cognex), tamoxifen, terbinafine (Lamisil), valproic acid, and zileuton (Zyflo).
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 thing about tolcapone (Tasmar): it already comes with a serious warning about liver injury, which is why your doctor checks your liver enzymes with regular blood tests while you take it. The concern with Manchurian Thorn isn't about how tolcapone is broken down. Instead, it's that both can be hard on the liver, so stacking them together could add up and raise your risk of liver trouble.

I'll be straight with you: this caution comes only from animal studies using high doses, so it's theoretical, not proven in people. Still, since tolcapone is one of the riskier Parkinson's medicines for the liver, I'd play it safe. Please check with your doctor or pharmacist before pairing the two, and watch for yellowing skin, dark urine, belly pain, or unusual tiredness.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Burgos R, Hancke J, Caceres DD, et al. Hepatotoxic effect of Aralia mandshurica dried root extract in pigs. Phytotherapy Res 1997;11(1):59-61. DOI
  2. Burgos R, Hancke J, Wikman G, et al. Toxicological assessment of Aralia mandshurica (Araliaceae) root extract after subchronic administration in rats. A biochemical and histological study. Phytotherapy Res 1994;8(1):1-9.

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

Manchurian Thorn Also Interacts With Other Medications

Manchurian Thorn has 441 moderate known drug interactions in our database — the Tolcapone one above is one of them. If you take anything else, check it against the full list below.

Moderate 441 No known interaction 2,389 (incl. Tolcapone)
Taking anything else?

Check Another of Your Medications Against Manchurian Thorn

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

Everything else you take

See Every Supplement That Interacts With Tolcapone

This page covers Manchurian Thorn only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tolcapone page lists 58 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Siberian Cocklebur (major), Wine (major) and Ashwagandha (moderate).

By severity: 4 major · 45 moderate · 9 minor.

Open the Tolcapone interaction page

One more smart check

Taking Manchurian Thorn as Part of a Dietary Supplement Product? Check It for Interactions

We hold 5 real supplement products containing Manchurian Thorn, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Manchurian Thorn. Your product may carry other ingredients that interact with Tolcapone too, on top of Manchurian Thorn — 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 Manchurian Thorn and Tolcapone 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 Manchurian Thorn
Top half

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

29 days ago today
Medication Tolcapone
Steady interest

#2,476 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 Manchurian Thorn

What is Manchurian Thorn?

  • Blood sugar support
  • Joint and arthritis discomfort
  • Fatigue and general weakness
  • Digestive complaints
  • General tonic / adaptogen-like use

Manchurian Thorn (Aralia elata) is a thorny shrub or small tree used in traditional East Asian medicine, mainly for blood sugar, joint pain, and as a general tonic. Human evidence is very limited, so its benefits are not well proven. If you are considering it, talk with your pharmacist or doctor first, and avoid it during pregnancy and breastfeeding.

Read the full Manchurian Thorn monograph & all interactions
Medication

About Tolcapone

What Is Tolcapone Used For?

Brand name: Tasmar

Tolcapone tablets (sold as Tasmar and as generic tolcapone) are used as an add-on therapy to levodopa/carbidopa for idiopathic Parkinson's disease — meaning Parkinson's that arises on its own, not from another cause. It is intended for patients who are experiencing symptom fluctuations and are not responding well to, or are not good candidates for, other add-on treatments.

Because of the serious risk of liver failure, tolcapone is reserved for patients who need additional symptom control and must be stopped within 3 weeks if it is not producing a clear benefit.

See full Tolcapone drug information
Keep checking

Other Drugs & Manchurian Thorn

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

0Major
441Moderate
0Minor
2,388No known interaction
441 Moderate 2,388 No interaction
Moderate

441 interactions

Showing 60 of 441 moderate interactions — see all 441 on the Manchurian Thorn page.

No interaction 2,388 drugs checked — show the list

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

Showing the 60 most looked-up of 2,388 medications checked with no known interaction — see the full Manchurian Thorn list.

See the full Manchurian Thorn interactions page
See every supplement checked against Tolcapone, 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
Manchurian Thorn monograph › Uses, safety, and every drug interaction in one place Tolcapone supplement interactions › Every supplement checked against Tolcapone, ranked by severity Tolcapone 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 Manchurian Thorn and Tolcapone Together: Common Questions

Can you take Manchurian Thorn with Tolcapone?
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 Manchurian Thorn and Tolcapone 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 Tolcapone and Manchurian Thorn?

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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.