Evaluating how oregano affects drug metabolism

Evaluating the Pharmacokinetics of Oregano and Potential Oregano-drug Interactions Using a Drug Cocktail Approach

Early Phase 1 Interventional Washington State University · NCT06693960

This study is testing whether taking oregano supplements affects how the body processes certain medications in healthy adults.

Quick facts

PhaseEarly Phase 1
Study typeInterventional
Enrollment16 (estimated)
Ages18 Years to 64 Years
SexAll
SponsorWashington State University Academic / other
Locations1 site (Spokane, Washington)
Trial IDNCT06693960 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to investigate the impact of oregano on the pharmacokinetics of pharmaceutical drugs. By utilizing a drug cocktail approach, the study will assess how oregano supplements may influence the activity of key drug-metabolizing enzymes, particularly cytochrome P450 enzymes. Healthy participants aged 18-64 will be recruited, and they will need to abstain from various substances that could interfere with the study. The findings could provide insights into potential drug interactions caused by oregano consumption.

Who should consider this trial

Good fit: Ideal candidates for this study are healthy adults aged 18-64 who are not taking any medications or supplements that could interfere with drug metabolism.

Not a fit: Patients currently taking medications or dietary supplements that affect drug metabolism may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could help identify potential drug interactions with oregano, improving patient safety and medication management.

How similar studies have performed: While there is existing research on herbal supplements and drug interactions, this specific investigation into oregano's effects is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Between 18-64 years old and healthy
* Not taking any medications (prescription and non-prescription) or dietary/herbal supplements that can interfere with study drug pharmacokinetics
* Willing to abstain from consuming dietary/herbal supplements and citrus juices for several weeks
* Willing to abstain from cannabis/marijuana, hemp, and THC- and CBD-containing products for several weeks
* Willing to abstain from consuming caffeinated beverages or other caffeine-containing products the evening before and the morning of the first day of each study arm
* Willing to abstain from consuming any alcoholic beverages for at least 1 day prior to any study day and during the study day
* Willing to use a secondary method of birth control that does not include the introduction or discontinuance of hormonal-based birth control (such as abstinence, copper IUD, or condoms). Specifically, regardless of the use hormonal-based birth control, a non-hormonal method should be used for the duration of the study and for three weeks following cessation of participation.
* Willing to abstain from consuming oregano (as a food additive or otherwise) for the duration of the study
* Geographically located within a 40-mile radius of Spokane and have the time to participate

Exclusion Criteria:

* Under 18 or over 64 years old
* Taking medications or dietary/herbal supplements that can interfere with study drug pharmacokinetics
* Have a major illness
* Taking medication/supplements for a mineral deficiency
* History of intolerance or allergy to oregano or any of the cocktail drugs (caffeine, dextromethorphan, losartan, midazolam, and omeprazole)
* Use of cannabis/marijuana, hemp, and CBD- and/or THC-containing products within the last month
* Currently using drugs or illicit substances for recreational purposes
* Pregnant or nursing
* Geographically located outside the 40-mile radius of Spokane and do not have the time to participate
* Cannot read and speak English

Where this trial is running

Spokane, Washington

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Interactionpharmacokineticsdrug interactionnatural productsoreganocytochrome P450cocktail
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.