Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
This randomized, double-blind, placebo-controlled study evaluates the acute physiological and subjective responses to essential oil inhalation in healthy adults. Participants are assigned to inhale either an essential oil or a placebo via an aroma stick during standardized laboratory procedures designed to induce temporary psychosocial stress (Trier Social Stress Test - Group version) and during a guided relaxation session.
Physiological responses, including heart rate, heart rate variability, and electrodermal activity, are measured using a wearable sensor. Subjective stress and affect are assessed using validated questionnaires and visual analog scales. The purpose of this study is to characterize short-term autonomic and self-reported responses associated with essential oil inhalation under controlled experimental conditions. This study is exploratory and is not intended to diagnose, treat, or prevent any medical condition.
Essential oils and essential oil blends are widely used in non-clinical settings; however, objective data describing short-term physiological and subjective responses to inhalation under controlled experimental conditions remain limited. This study is designed to evaluate acute autonomic and self-reported responses to essential oil inhalation during standardized laboratory procedures involving psychosocial stress and guided relaxation.
This is a randomized, double-blind, placebo-controlled, parallel-group study conducted in healthy adults aged 18-45 years. Participants are assigned to inhale either an essential oil (or essential oil blend) or a placebo comparator administered via an identical aroma stick. Inhalation occurs at standardized time points during two study visits.
During Study Visit 1, participants undergo the Trier Social Stress Test - Group version (TSST-G), a validated laboratory paradigm designed to induce temporary psychosocial stress through public speaking and mental arithmetic tasks performed under observation. Inhalation occurs during baseline, preparation, stress, and recovery phases. During Study Visit 2, participants undergo a structured guided meditation session under controlled environmental conditions, with inhalation occurring at standardized intervals.
Physiological measures are collected continuously using a wrist-worn wearable device capable of measuring heart rate, heart rate variability (HRV), and electrodermal activity (EDA). Subjective responses are assessed using validated instruments including visual analog scales for stress and calm, PROMIS Anxiety, GAD-7, and PANAS. The primary outcome is change in stress response as measured by area under the curve (AUC) for visual analog scale stress scores across the stress and recovery period.
The study employs an adaptive design with an initial planned enrollment of 100 participants (50 per arm) and a prespecified interim analysis for potential expansion to a maximum of 200 participants. Statistical analyses include comparison of stress and physiological responses between groups using baseline-adjusted models.
This study is exploratory in nature and is intended to characterize acute responses associated with essential oil inhalation under controlled conditions. It is not designed to diagnose, treat, mitigate, or prevent any disease or medical condition.
Not provided
Not provided
Not provided
Not provided
| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Essential Oil Inhalation | Experimental | Participants inhale an essential oil or essential oil blend via an individual aroma stick during standardized stress induction (TSST-G) and guided relaxation procedures across two study visits. |
|
| Placebo Inhalation | Placebo Comparator | Participants inhale a placebo aroma stick matched in appearance and delivery method but without active essential oil components during identical stress and relaxation procedures. |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Essential Oil Inhalation | Other | Participants inhale an essential oil or essential oil blend administered via an individual aroma stick. At prespecified time points during baseline, stress induction (Trier Social Stress Test - Group version), and recovery or guided meditation procedures, participants are instructed to take five normal breaths from the aroma stick. The intervention is delivered in a randomized, double-blind manner and is standardized across participants within each study phase. |
| Measure | Description | Time Frame |
|---|---|---|
| Change in Visual Analog Scale (VAS) Stress Area Under the Curve (AUC) | Area under the curve (AUC) for self-reported stress measured using a Visual Analog Scale (VAS) across baseline, stress induction (Trier Social Stress Test - Group version), and post-stressor recovery periods. The VAS-stress scale ranges from low stress to high stress, with higher scores indicating greater perceived stress. | Baseline through 30 minutes post-stressor recovery (Study Visit 1) |
Not provided
| Measure | Description | Time Frame |
|---|---|---|
| Change in Heart Rate During Stress and Recovery | Mean heart rate measured using a wearable sensor during baseline, stress induction (Trier Social Stress Test - Group version), and post-stressor recovery. A higher heart rate, measured beats per minute (BPM), indicates higher stress. | Baseline through 30 minutes post-stressor recovery (Study Visit 1), approximately 90 minutes from baseline |
Inclusion Criteria:
Age 18-45 years, inclusive
Able to read, write, and understand English
Willing and able to provide informed consent
Willing to attend two in-person study visits
Generally healthy, as determined by medical history and screening review
Exclusion Criteria:
Known asthma, chronic obstructive pulmonary disease (COPD), significant lung disease, heart disease, or other medical condition that may compromise safety or data integrity
Pregnancy or pregnancy within the past 90 days
Known allergy or sensitivity to essential oils or study placebo materials
Current smoking, vaping, chewing tobacco, or use of recreational drugs
Regular use of essential oils applicable to the study phase (>3 times per week for â¥2 weeks within the past month) without a minimum 1-month washout
Unwillingness to abstain from alcohol for at least 72 hours prior to each study visit
Failure to meet inclusion criteria
Not provided
Not provided
Not provided
Not provided
Not provided
| Name | Affiliation | Role |
|---|---|---|
| Nicole Stevens, PhD | DoTERRA International LLC. | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| dÅTERRA International | Pleasant Grove | Utah | 84062 | United States |
Not provided
| ID | Term |
|---|---|
| D013315 | Stress, Psychological |
| D001008 | Anxiety Disorders |
| ID | Term |
|---|---|
| D001526 | Behavioral Symptoms |
| D001519 | Behavior |
| D001523 | Mental Disorders |
Not provided
Not provided
Participants are randomized in a 1:1 ratio to one of two parallel groups: essential oil inhalation or placebo inhalation. Randomization is maintained across two study visits. Participants remain in their assigned group for the duration of the study. An initial cohort of 100 participants (50 per arm) will be enrolled, with a prespecified interim analysis to determine whether enrollment will expand to a maximum of 200 participants.
Not provided
Not provided
Not provided
|
| Placebo Aroma Stick | Other | Participants inhale a placebo comparator administered via an aroma stick identical in appearance and delivery method to the experimental intervention but without active essential oil components. The inhalation schedule and procedures are identical to those used in the experimental arm to maintain blinding. |
|
| Change in Electrodermal Activity During Stress and Recovery | Tonic electrodermal activity measured using a wearable sensor during baseline, stress induction, and recovery periods. This is measured in microsiemens, which is the SI unit of conductance. Higher tonic ectodermal activity indicates higher stress. | Baseline through 30 minutes post-stressor recovery (Study Visit 1), approximately 90 minutes from baseline. |
| Change in PROMIS Anxiety Scores | PROMIS Anxiety short form scores collected at baseline and during post-stressor recovery to assess subjective anxiety symptoms. A higher score indicates higher anxiety. The measurement scale ranges from 1 ("never") to 5 ("always"). | Baseline and post-stressor recovery (Study Visit 1), approximately 90 minutes from baseline. |
| Change in Positive and Negative Affect Schedule (PANAS) Scores | PANAS scores assessing positive and negative affect collected at baseline and post-stressor recovery. The rating scale ranges from 1 ("Very slightly or not at all") to 5 ("extremely"). Higher scores with regard to the positive affect questions indicate greater levels of joy, enthusiasm, and active engagement. Higher scores with regard to the negative affect questions indicate higher levels of fear, anger, or distress. | Baseline and post-stressor recovery (Study Visit 1), approximately 90 minutes from baseline |
| Change in Visual Analog Scale (VAS) Calm Scores | Self-reported calmness measured using a visual analog scale across baseline, stress, and recovery phases. It is measured on a score of 0 to 100, with 0 representing "Not at all", and 100 representing "extremely". | Baseline through 30 minutes post-stressor recovery (Study Visit 1), approximately 90 minutes after baseline. |
| Incidence of Adverse Events | Number and severity of participant-reported adverse events occurring during study visits. | Through completion of Study Visit 2, up to 1 week post baseline. |