Wheatgrass - Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine Interaction
Herbal: Wheatgrass
Also Known As: Triticum aestivum, Agropyre, Blé en Herbe, Bread Wheat, Brote del Trigo, Common Wheat, Grano, Herbe de Blé, Wheat, Wheat Grass
Drug: Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine
Brand names:
Conar-A

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 04, 2025
Interaction Details
Acetaminophen, Dextromethorphan, Guaifenesin, Phenylephrine is classified as belonging to the following category: Cytochrome P450 1A2 (Cyp1A2) Substrates
Theoretically, wheatgrass might decrease the levels and clinical effects of CYP1A2 substrates.
In vitro research shows that wheatgrass induces CYP1A2 enzymes.
Interaction Rating
Likelihood of Occurrence
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
References
- 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.
Wheatgrass Overview

Wheatgrass - More Interactions
Wheatgrass interacts with 269 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
Unknown | No interactions have been reported or no interaction data is currently available. |
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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.
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Drug descriptions are provided by MedlinePlus.