Drug & supplement interaction

Wheatgrass + Tizanidine

Tizanidine brand names: Zanaflex, Ontralfy.

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

Wheatgrass has a moderate interaction with Tizanidine. Theoretically, wheatgrass might decrease the levels and clinical effects of CYP1A2 substrates.

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

Wheatgrass and Tizanidine

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

Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

Why this applies to Tizanidine

Tizanidine falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Wheatgrass interacts with.

Theoretically, wheatgrass might decrease the levels and clinical effects of CYP1A2 substrates.
In vitro research shows that wheatgrass induces CYP1A2 enzymes.
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 situation with these two. Your body relies on an enzyme called CYP1A2 to clear tizanidine out of your system. Some early lab research suggests wheatgrass may speed that enzyme up a bit. If that happened in real life, your body could break down tizanidine a little faster, which might make it less effective at easing your muscle spasms and tightness.

I want to be honest about how shaky this evidence is. This concern comes only from test-tube and animal studies, not from people, so it's very much theoretical. Tizanidine isn't a prodrug, so it doesn't flip the other way. Most likely a glass of wheatgrass juice won't cause trouble, but if you take concentrated supplements regularly, mention it to your pharmacist or doctor and watch whether your medication still feels like it's working.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. 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

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

Wheatgrass Also Interacts With Other Medications

Wheatgrass has 271 moderate known drug interactions in our database — the Tizanidine one above is one of them. If you take anything else, check it against the full list below.

Moderate 271 No known interaction 2,559 (incl. Tizanidine)
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.

From our Q&A

Questions About Wheatgrass or Tizanidine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Wheatgrass or Tizanidine, 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 Tizanidine

This page covers Wheatgrass only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tizanidine page lists 143 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), Beer (major) and Cesium (major).

By severity: 11 major · 101 moderate · 31 minor.

Open the Tizanidine 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. Your product may carry other ingredients that interact with Tizanidine too, on top of Wheatgrass — 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 Wheatgrass and Tizanidine 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

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

29 days ago today
Medication Tizanidine
Steady interest

#1,823 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 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.

Read the full Wheatgrass monograph & all interactions
Medication

About Tizanidine

What Is Tizanidine Used For?

Brand names: Zanaflex, Ontralfy

Tizanidine — available as tablets, capsules, and as the oral solution Ontralfy — is used to manage spasticity (abnormal muscle stiffness or spasms). Because it works for a relatively short window of time, it is typically scheduled around the activities when spasm relief matters most.

Ontralfy (oral solution) and Zanaflex capsules are specifically indicated for the treatment of spasticity in adults. Other tizanidine tablets and capsules are indicated for the management of spasticity more broadly.

See full Tizanidine 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
271Moderate
0Minor
2,558No known interaction
271 Moderate 2,558 No interaction
Moderate

271 interactions

Showing 60 of 271 moderate interactions — see all 271 on the Wheatgrass page.

No interaction 2,558 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 2,558 medications checked with no known interaction — see the full Wheatgrass list.

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

Can you take Wheatgrass with Tizanidine?
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 Wheatgrass and Tizanidine 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 Tizanidine 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.