Rosemary - Vicks NyQuil (Acetaminophen, Dextromethorphan, Doxylamine, Pseudoephedrine) Interaction
Herbal: Rosemary
Also Known As: Rosmarinus officinalis, Alecrim, Compass Plant, Compass Weed, Encensier, Herbe Aux Couronnes, Old Man, Polar Plant, Romarin, Romarin Des Troubadours, Romero, Rose de Marie, Rose Des Marins, Rosée De Mer, Rosemarine, Rusmari, Rusmary
Drug: Acetaminophen, Dextromethorphan, Doxylamine, Pseudoephedrine
Brand names:
Vicks NyQuil

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 04, 2025
Interaction Details
Acetaminophen, Dextromethorphan, Doxylamine, Pseudoephedrine is classified as belonging to the following category: Cytochrome P450 1A2 (Cyp1A2) Substrates
Theoretically, rosemary might decrease the levels and clinical effects of CYP1A2 substrates.
In vitro research shows that rosemary induces CYP1A2 enzymes. This effect has not been reported in humans.
Interaction Rating
Likelihood of Occurrence
UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
References
- Debersac P, Heydel JM, Amiot MJ, et al. Induction of cytochrome P450 and/or detoxication enzymes by various extracts of rosemary: description of specific patterns. Food Chem Toxicol 2001;39(9):907-18.
- Debersac P, Vernevaut MF, Amiot MJ, et al. Effects of a water-soluble extract of rosemary and its purified component rosmarinic acid on xenobiotic-metabolizing enzymes in rat liver. Food Chem Toxicol 2001;39(2):109-17.
Rosemary Overview

Rosemary - More Interactions
Rosemary interacts with 368 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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