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).

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.

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