Pharmacokinetics of Essential Oils in Different Capsules

Pharmacokinetic Evaluation of Essential Oils in Different Capsule Matrices

This open label study will recruit healthy adults to investigate the pharmacokinetics of oral ingestion of frankincense, lemon, and wild orange essential oils. This study will also evaluate whether the delivery matrix (capsule type) affects the pharmacokinetics of the oils. Secondary outcomes include safety markers (liver and kidney function, hematology, urinalysis, and adverse events).

Study Overview

• Status: Completed
• Conditions: Healthy; Health, Subjective
• Intervention / Treatment: Other: Frankinscense Essential Oil Capsule; Other: Lemon Essential Oil Capsule; Other: Wild Orange Essential Oil Capsule

Detailed Description

This open label study will recruit healthy adults to investigate the pharmacokinetics of oral ingestion of frankincense, lemon, and wild orange essential oils. This study will also evaluate whether the delivery matrix (capsule type) affects the pharmacokinetics of the oils. Secondary outcomes include safety markers (liver and kidney function, hematology, urinalysis, and adverse events). Samples will be collected at 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, and 24 hours after ingestion of assigned essential oil. Blood and urine markers will be assessed to determine the pharmacokinetics of each essential oil and how the capsule matrix effects these.

Pharmacokinetic parameters will be measured in serum. Chromatography and mass spectrometry will be used to detect and measure the essential oil constituents of interest in serum. Each arm of the study includes a pharmacokinetic analysis, and arms will be compared to one another. T-max (time to constituent concentration maximum in serum), C-max (maximum constituent concentration level), and T1/2 (time for the constituent concentration to decrease by half) will serve as the primary outcome measurements. Pharmacokinetics analysis software will be used to generate pharmacokinetic data from the chromatography and mass spectrometry results.

• Study Type: Interventional
• Enrollment (Actual): 19
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Mississippi
    • Jackson, Mississippi, United States, 39216
      • University of Mississippi Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Selection Criteria:

Participants must meet all the following criteria:

• Adults ages 18-35 years old
• Local to metropolitan Jackson, MS, and/or willing to come to the clinical research center for study visits
• Willing to wash out of all internally consumed essential oil and botanical products for at least 2 weeks prior to starting the study and willing to maintain the washout for the duration of the study (approximately 8 weeks)
• Willing to avoid all frankincense, wild orange, and lemon essential oil in any form (aromatic, topical, or internal) for the duration of the study (approximately 5 weeks).
• Willing to avoid alcohol, recreational drugs, and smoking/vaping for 3 days prior to each arm of the study
• Willing to receive an intravenous catheter in the arm or hand every two weeks for 4 weeks (three times total)
• History of successful blood/plasma donation, IV insertion, or blood collection by phlebotomy
• Weigh at least 110 pounds
• No uncontrolled metabolic disease
• No unstable major diseases under treatment by healthcare professional
• No pregnancy within the last 60 days or currently breastfeeding (females)
• No allergy to olive oil or frankincense, lemon, or wild orange essential oils
• No regular internal consumption of frankincense, lemon, or wild orange essential oil regularly within the last 1 month (regularly is defined as dosing daily for more than 2 consecutive weeks, or dosing more than 2-3 times per week for 4 consecutive weeks)
• No alcohol, recreational drug, or smoking/vaping use in the past 3 days
• No evidence of medical condition, significant disease or disorder, medication, or surgery within the past 12 months that may, in the judgment of the medical provider, put the participant at risk or affect study results, procedures, or outcomes
• Not currently or previously participating in any other clinical trial within the last 30 calendar days

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Frankinscense; Frankincense essential oil capsule (150mg per visit). Participants will consume one capsule containing 150 mg of frankincense oil and 150 mg of olive oil at each visit.	Other: Frankinscense Essential Oil Capsule; Frankincense essential oil capsule (150mg per visit). Participants will consume one capsule containing 150 mg of frankincense oil and 150 mg of olive oil at each visit. At the first visit, participants will receive the essential oil in a delayed-release hypromellose (HPMC capsule), followed by a HPMC Capsule at the second visit, and a Tapioca softgel capsule at the third visit.
Experimental: Lemon; Lemon essential oil capsule (150mg per visit). Participants will consume two capsules: one capsule containing 150 mg of lemon oil and one capsule containing 150 mg of olive oil at each visit.	Other: Lemon Essential Oil Capsule; Lemon essential oil capsule (150mg per visit). Participants will consume one capsule containing 150 mg of frankincense oil and one capsule containing 150 mg of olive oil at each visit. At the first visit, participants will receive the essential oil in a delayed-release hypromellose (HPMC capsule), followed by a HPMC Capsule at the second visit, and a Tapioca softgel capsule at the third visit.
Experimental: Wild Orange; Wild Orange essential oil capsule (150mg per visit). Participants will consume two capsules: one capsule containing 150 mg of wild orange oil and once capsule containing 150 mg of olive oil at each visit.	Other: Wild Orange Essential Oil Capsule; Wild Orange essential oil capsule (150mg per visit). Participants will consume one capsule containing 150 mg of frankincense oil and once capsule containing 150 mg of olive oil at each visit. At the first visit, participants will receive the essential oil in a delayed-release hypromellose (HPMC capsule), followed by a HPMC Capsule at the second visit, and a Tapioca softgel capsule at the third visit.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to constituent concentration maximum in serum (T-max)	Amount of time it takes for each essential oil to reach the maximum concentration in serum compared to baseline, 30 minutes, 1 hour, 1 hour 30 minutes, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 8 hours, and 24 hours.	24 hours
Maximum constituent concentration level (C-max)	Maximum amount of each essential oil concentration measured in the blood. Timepoints will be measured at baseline, 30 minutes, 1 hour, 1 hour 30 minutes, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 8 hours, and 24 hours.	24 hours
Time for the constituent concentration to decrease by half (T 1/2)	Amount of time it takes for each essential oil level to decrease by half as measured at baseline, 30 minutes, 1 hour, 1 hour 30 minutes, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 8 hours, and 24 hours.	24 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference in T-max for each capsule type	Difference in the T-max levels compared between the types of capsule types based off analysis from primary outcomes.	24 hours
Difference in C-max for each capsule type	Difference in the C-max levels compared between the types of capsule types based off analysis from primary outcomes.	24 hours
Difference in T 1/2 for each capsule type	Difference in the T-max levels compared between the types of capsule types based off analysis from primary outcomes.	24 hours

Collaborators and Investigators

• Sponsor: University of Mississippi Medical Center
• Investigators: Principal Investigator: Gailen D Marshall Jr., MD, PhD, University of Mississippi Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): July 2, 2025
• Primary Completion (Actual): December 19, 2025
• Study Completion (Actual): December 19, 2025

Study Registration Dates

• First Submitted: May 23, 2025
• First Submitted That Met QC Criteria: May 5, 2026
• First Posted (Actual): May 12, 2026

Study Record Updates

• Last Update Posted (Actual): May 12, 2026
• Last Update Submitted That Met QC Criteria: May 5, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Frankincense; Essential Oils; Lemon; Wild Orange
• Other Study ID Numbers: 2025-112

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No