This randomized, double-blind, placebo-controlled clinical trial will evaluate the safety and efficacy of an essential oil-based product system for immune support in healthy adolescents and adults aged 18-45 years. Participants will be randomized to receive aromatic, topical, internal, or combined use of the investigational product or matching placebo for 30 days.

The aromatic intervention consists of overnight diffusion, the topical intervention consists of diluted application to specified areas prior to bedtime, and the internal intervention consists of oral capsule administration twice daily. Study visits will occur at baseline and at the end of the 30-day intervention period.

Primary outcomes include changes in immune-related biomarkers, including complete blood count, comprehensive metabolic panel, salivary immunoglobulin A (IgA), and inflammatory cytokines (IL-6, TNF-α, IL-10). Epigenetic markers will also be evaluated. Secondary outcomes include validated subjective assessments of immune status and overall well-being, as well as evaluation of safety and tolerability.

The study includes an adaptive design with interim analysis to assess enrollment and study continuation parameters.

This study is a randomized, double-blind, placebo-controlled, parallel-group clinical trial designed to evaluate the safety and efficacy of a multi-modal essential oil-based product system in healthy adolescents and adults aged 18-45 years. Approximately 20 participants per arm will be enrolled and randomized, with the option for sample size expansion following a planned interim analysis.

Participants will be randomized to receive either the investigational product or matching placebo administered through one of four intervention approaches: aromatic use, topical use, internal use, or combined use of all three modalities. The intervention period will be 30 days.

The aromatic intervention consists of diffusion of the assigned product overnight (approximately 8 hours) using a standardized protocol. The topical intervention consists of application of a diluted preparation to specified skin areas prior to bedtime. The internal intervention consists of oral capsule administration twice daily with meals. Participants assigned to the combined group will use all three modalities concurrently. Placebo preparations will be matched for appearance and administration method.

Study assessments will occur at baseline and at the end of the 30-day intervention period. Biological samples will be collected for evaluation of immune-related biomarkers, including complete blood count (CBC), comprehensive metabolic panel (CMP), salivary immunoglobulin A (IgA), and inflammatory cytokines (interleukin-6 [IL-6], tumor necrosis factor alpha [TNF-α], and interleukin-10 [IL-10]). Epigenetic analyses will also be conducted to evaluate changes in gene expression patterns associated with immune function.

Validated subjective outcome measures, including the PROMIS Global Health instrument and the Immune Status Questionnaire, will be administered to assess perceived immune status and overall well-being. Participants will complete compliance and tolerability reporting throughout the study period.

Safety monitoring will include assessment of adverse events, with particular attention to dermatologic, respiratory, and gastrointestinal symptoms potentially associated with essential oil exposure. The study incorporates an adaptive design with planned interim analysis after initial enrollment targets are reached to guide potential expansion or completion of study arms.

The primary objective is to evaluate changes in immune-related biomarkers following 30 days of product use. Secondary objectives include assessment of subjective immune status, hedonic response, and safety/tolerability of aromatic, topical, internal, and combined administration modalities.

Inclusion Criteria:

• Healthy male or female participants aged 18 to 45 years
• Able to read, write, and understand English
• Willing and able to attend study visits at the study site
• Willing to comply with study procedures, including daily use of assigned study product for 30 days
• Willing to refrain from use of essential oils (topical, aromatic, or internal) outside of the study during the study period
• If previously using essential oils regularly (defined as more than 3 times per week for 2 or more weeks in the past month), must complete a washout period of at least 1 month prior to enrollment

Exclusion Criteria:

• Known asthma, chronic obstructive pulmonary disease (COPD), chronic lung disease, heart disease, or other medical condition that would make inhalation of essential oils unsafe, as determined by the investigator
• Known allergy or hypersensitivity to essential oils or components of the placebo preparation
• Current use of tobacco products, including smoking, vaping, or chewing tobacco
• Use of recreational drugs
• Pregnant or breastfeeding, or pregnancy within the past 3 months
• Current regular use of essential oils (defined as more than 3 times per week for 2 or more weeks within the past month) without completion of a 1-month washout period
• Initiation of new botanical supplements during the study period
• Any medical, psychiatric, or social condition that, in the opinion of the investigator, would interfere with safe participation or study compliance

This study is double-blind. Participants, investigators, study staff, and outcome assessors will be blinded to treatment assignment. Active and placebo products will be matched in appearance, packaging, labeling, and method of administration. Randomization codes will be generated and maintained by an independent party and will not be accessible to blinded study personnel. Unblinding will occur only after completion of the study or at the time of a pre-specified interim analysis conducted by a designated statistician not involved in participant interaction or outcome assessment.