Drug & supplement interaction

Wheatgrass + Tolcapone

Tolcapone brand name: Tasmar.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Wheatgrass and Tolcapone 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

Wheatgrass and Tolcapone

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 Tolcapone and Wheatgrass 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.

Wheatgrass safety at a glance

Wheatgrass overall Use caution Generally well tolerated as a food, but quality and contamination concerns mean caution is wise.
Pregnancy Avoid Safety is not established, and raw products may carry contamination risk, so avoid unless cleared by your doctor.
Breastfeeding Avoid There is not enough safety information, so avoid unless your doctor approves.

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

Still wondering about combining Tolcapone and Wheatgrass? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Tolcapone

Interactions in our licensed database are recorded against drug classes, not just single drug names. Tolcapone is filed under 3 classifications — dopamine agonists, hepatotoxic drugs, oral drugs. Wheatgrass has documented interactions with 2 drug classes — the most serious being antidiabetes drugs (moderate) and cytochrome p450 1a2 (cyp1a2) substrates (moderate) — and none of Tolcapone’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

Wheatgrass Does Interact With Other Medications

Wheatgrass has 272 moderate known drug interactions in our database — Tolcapone isn’t one of them. If you take anything else, check it against the full list below.

Moderate 272 No known interaction 2,558 (incl. Tolcapone)
Taking anything else?

Check Another of Your Medications Against Wheatgrass

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

What to actually watch for

No Interaction Found — But Data Suggests Wheatgrass and Tolcapone 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.

  • An allergic reaction Worth acting on Additional detail

    Wheatgrass

    “Wheat can cause allergic reactions in sensitive individuals. Due to the prevalence of this allergy in the general population, wheat and wheat products, such as wheatgrass, are classified as major food allergens in the United States.”

    Wheatgrass · Natural Medicines adverse-effect record, reported in allergic rhinitis (hay fever).

    1 source cited
    1. 105410. Food and Drug Administration. Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA); Public Law 108-282, Title II. Accessed on May 19, 2021. Available at: https://www.fda.gov/food/food-allergensgluten-free-guidance-documents-regulatory-infor

    Tolcapone

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

  • Reduced appetite / Constipation / Nausea Additional detail

    Wheatgrass

    “Orally, wheatgrass may cause nausea, anorexia, and constipation.”

    Wheatgrass · Natural Medicines adverse-effect record, reported in anorexia.

    1 source cited
    1. 11165. Ben-Arye E, Golden E, Wengrower D, et al. Wheat grass juice in the treatment of active distal ulcerative colitis a randomized double-blind placebo-controlled trial. Scand J Gastroenterol 2002;4:444-9.. PubMed

    Tolcapone

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

Effects for Tolcapone come from the ADVERSE REACTIONS section of its FDA label; effects for Wheatgrass 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.

Everything else you take

See Every Supplement That Interacts With Tolcapone

This page covers Wheatgrass 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 Wheatgrass as Part of a Dietary Supplement Product? Check It for Interactions

We hold 104 real supplement products containing Wheatgrass, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Wheatgrass. Even though Wheatgrass itself has no known interaction with Tolcapone, 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 Wheatgrass 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 Wheatgrass
Top half

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

29 days ago today
Medication Tolcapone
Steady interest

#2,465 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 Wheatgrass reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Wheatgrass and Tolcapone 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 Wheatgrass

What is Wheatgrass?

Wheatgrass
  • General nutrition support
  • Digestive health
  • Antioxidant support
  • Energy and wellness
  • Arthritis symptoms
  • Detox or cleansing routines

Wheatgrass is the young grass of the wheat plant, taken as a juice or powder, and is mainly used as a concentrated source of vitamins and plant nutrients. Solid scientific evidence for most health claims is limited, and it is best viewed as a nutritional add-on rather than a treatment. It is generally well tolerated, but people with celiac disease, wheat allergy, or who are pregnant should be cautious and check with a healthcare provider.

Triticum aestivum · Poaceae · Young grass (leaves/shoots) of the wheat plant · Fresh juice, powder, tablets, capsules, and added to smoothies or health drinks

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

Wheatgrass: dosing

There is no official or standardized dose for wheatgrass. Amounts vary widely between fresh juice, powder, and tablets, so the right amount depends on the specific product.The safest approach is to follow the directions on the product label and start with a small amount to see how your body responds.

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

Read the full Wheatgrass 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.

Most-Reported Side Effects for Tolcapone

From FAERS, the FDA’s public side-effect reporting system (349 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fall 30 reports
Hallucination 27 reports
Dyskinesia 26 reports
Pneumonia 20 reports
General physical health deterioration 19 reports
See full Tolcapone drug information
Keep checking

Other Drugs & Wheatgrass

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

0Major
272Moderate
0Minor
2,557No known interaction
272 Moderate 2,557 No interaction
Moderate

272 interactions

Showing 60 of 272 moderate interactions — see all 272 on the Wheatgrass page.

No interaction 2,557 drugs checked — show the list

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

Showing the 60 most looked-up of 2,557 medications checked with no known interaction — see the full Wheatgrass list.

See the full Wheatgrass interactions page
See every supplement checked against Tolcapone, ranked by severity
Evidence & sources

Wheatgrass References

The 5 references that drive our Wheatgrass 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. Ben-Arye E, Golden E, Wengrower D, et al. Wheat grass juice in the treatment of active distal ulcerative colitis a randomized double-blind placebo-controlled trial. Scand J Gastroenterol 2002;4:444-9.. PubMed
  2. Mohan Y, Jesuthankaraj GN1, Ramasamy Thangavelu N. Antidiabetic and antioxidant properties of Triticum aestivum in streptozotocin-induced diabetic rats. Adv Pharmacol Sci 2013;2013:716073.
  3. Shakya G, Randhi PK, Pajaniradje S, Mohankumar K, Rajagopalan R. Hypoglycaemic role of wheatgrass and its effect on carbohydrate metabolic enzymes in type II diabetic rats. Toxicol Ind Health 2016;32(6):1026-32. PubMed
  4. Food and Drug Administration. Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA); Public Law 108-282, Title II. Accessed on May 19, 2021. Available at: https://www.fda.gov/food/food-allergensgluten-free-guidance-documents-regulatory-infor
  5. Haron MH, Dale O, Martin K, et al. Evaluation of the Herb-Drug Interaction Potential of Commonly Used Botanicals on the US Market with Regard to PXR- and AhR-Mediated Influences on CYP3A4 and CYP1A2. J Diet Suppl 2022. PubMed

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 Wheatgrass and Tolcapone Together: Common Questions

Is it safe to take Wheatgrass with Tolcapone?
We do not list a known interaction between Wheatgrass and Tolcapone. 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 Wheatgrass and Tolcapone have any of the same side effects?
Yes — our sources link each of them separately to 4 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 Wheatgrass and Tolcapone combination checked?
Interactions in our licensed database are recorded against drug classes. Tolcapone is filed under 3 classifications, and Wheatgrass has documented interactions with 2 drug classes — none of Tolcapone'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 Wheatgrass interact with any other medications?
Yes. Wheatgrass has 272 documented drug interactions in our database — Tolcapone 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 Tolcapone interact with any supplements?
Yes. Tolcapone has documented interactions with 58 supplements in our database — Wheatgrass is not one of them. The Tolcapone interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Wheatgrass monograph Uses, safety profile, and every drug interaction in one place Tolcapone drug information The full plain-English guide to this medication Tolcapone supplement interactions Every supplement checked against Tolcapone, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 5 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Tolcapone and Wheatgrass?

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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.