5-htp - DayQuil (acetaminophen, dextromethorphan, phenylephrine) Interaction
Herbal: 5-htp
Also Known As: 5 Hydroxy-Tryptophan, 5 Hydroxy-Tryptophane, 5-Hydroxytryptophan, 5-Hydroxytryptophane, 5-Hydroxy L-Tryptophan, 5-Hydroxy L-Tryptophane, 5-Hydroxy Tryptophan, 5-L-Hydroxytryptophan, L-5 HTP, L-5-Hydroxytryptophan, L-5-Hydroxytryptophane, Oxitriptan
Drug: acetaminophen, dextromethorphan, phenylephrine
Brand names:
DayQuil
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Apr 20, 2025
Interaction Details
There were no interactions found between acetaminophen, dextromethorphan, phenylephrine and 5-htp. This does not mean the potential for an interaction does not exist, however. There is often a lack of studies and data surrounding traditional medicine, especially concerning drug interactions, so it is important to always consult your provider before making any changes to your medication regimen.
5-htp Overview
5-HTP, or 5-hydroxytryptophan, is a naturally-occurring amino acid and a precursor to the neurotransmitter serotonin. It is used as a dietary supplement to improve mood and help with anxiety, sleep disorders, and other conditions. It is also sometimes used in combination with other medications to treat migraines and fibromyalgia. The 5-HTP found in supplements is most often obtained from the seeds of the tropical shrub Griffonia simplicifolia
5-htp - More Interactions
5-htp interacts with 394 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. |
Return to the main supplement interaction checker page
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
Drug descriptions are provided by MedlinePlus.
Ask A Pharmacist About Your Herbal Questions!
Dr. Brian Staiger, PharmD
In addition to being a clinical pharmacist specializing in pharmacotherapy, Dr. Brian Staiger is a registered herbalist through the American Herbalist Guild. He has combined his passion for pharmacy practice with the study of medical ethnobotany to improve patient care. Feel free to reach out about any of your herbal or medication questions!
Ask A Pharmacist