Valerian - NyQuil (acetaminophen, dextromethorphan, doxylamine) Interaction
Herbal: Valerian
Also Known As: Valeriana officinalis, All-Heal, Amantilla, Baldrian, Baldrianwurzel, Belgium Valerian, Garden Heliotrope, Garden Valerian, Tagar, Tagara, Valeriana, Valeriana Pseudofficinalis, Valériane Mexicaine
Drug: acetaminophen, dextromethorphan, doxylamine
Brand names:
NyQuil

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 04, 2025
Interaction Details
acetaminophen, dextromethorphan, doxylamine is classified as belonging to the following category: Cns Depressants
Valerian can have additive sedative effects when used concomitantly with CNS depressant drugs.
Theoretically, concomitant use of valerian and drugs with sedative and anesthetic properties may cause additive therapeutic and adverse effects.
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
Pharmacist Analysis
Valerian With NyQuil - Additional Details
NyQuil contains the sedating antihistamine doxylamine, which, when combined with valerian, can cause additive sedative effects.
While additive sedation may not be much of an issue if you are only planning on taking NyQuil in the evening to help you sleep, the interaction is still important to be aware of.
- Dr. Brian Staiger, PharmDReferences
- Houghton PJ. The scientific basis for the reputed activity of Valerian. J Pharm Pharmacol 1999;51:505-12.
- Yuan CS, Mehendale S, Xiao Y, et al. The gamma-aminobutyric acidergic effects of valerian and valerenic acid on rat brainstem neuronal activity. Anesth Analg 2004;98:353-8.
- Carrasco MC, Vallejo JR, Pardo-de-Santayana M, et al. Interactions of Valeriana officinalis L. and Passiflora incarnata L. in a patient treated with lorazepam. Phytother Res. 2009 Dec;23:1795-6.
Valerian Overview

Valerian - More Interactions
Valerian interacts with 878 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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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.
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Drug descriptions are provided by MedlinePlus.