Effects of Rosemary Essential Oil on Human Cognition (Rosmarinus)

April 28, 2026 updated by: Heloisa de Freitas Pacífico, Federal University of Paraíba

The Use of Rosmarinus Officinalis L. Essential Oil (Camphor and Cineol Chemotypes) in Cognition: a Randomized, Double-blind, Placebo-controlled Study

Aromatherapy is one of the complementary therapies that is carried out through essential oils. The essential oil of Rosmarinus Officinalis L. (rosemary) has been gaining attention in aromatherapy research, as studies have shown that the use of this oil is one of the promising non-pharmacological therapies for cognition. In this way, inhalation of rosemary essential oil is one of the forms of cognitive intervention across different age groups. The study will aim to analyze the effect of rosemary essential oil, with the following chemotypes: camphor and cineole, on the cognitive performance of adults. Significant differences are expected between the control (placebo) and experimental groups, given that studies in humans have already shown significant effects of rosemary essential oil on cognition. Considering the inclusion and exclusion criteria of the study, participants will be allocated to either the control or experimental group. Consequently, the application of the tests will be carried out neuropsychological tests for the pre-test evaluation, followed by aromatherapy (acute phase) and the reapplication of the tests (post-test phase 1). For 14 days, the participants will chronically use rosemary essential oil and at the end they will participate in the reapplication of the neuropsychological tests (post-test phase 2). For inferential analyses, the ANOVA test or its non-parametric equivalent will be used. In addition, linear regressions may be performed to verify how much the essential oil can predict the outcome of the study's dependent variables. Effect Size will also be calculated. Keywords: Chronic intervention; neuropsychology; aromatherapy.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

63

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Brazil
    • Paraíba
      • João Pessoa, Paraíba, Brazil, 58062-106
        • Helô

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

  1. Inclusion Criteria:

    • 1a Healthy adults
    • 1b should be able to inhale the essential oil

  2. Exclusion Criteria:

    • 2a Neurodegenerative diseases
    • 2b Traumatic brain injury
    • 2c Brain tumors
    • 2d Multiple sclerosis
    • 2e Epileptic seizures
    • 2f Anxiety Disorder
    • 2g Depressive Disorders,
    • 2h Uncontrolled arterial hypertension,
    • 2i nutritional deficiency or thyroid disease.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: essential oil of Rosmarinus officinalis 1
Inhalation of 2 drops of rosemary camphor essential oil for 5 minutes, once a day for 1 week consecutive on a cotton pad followed
Other: rosemary1
oil essential
No Intervention: Placebo
Inhalation of 2 drops of sunflower essential oil for 5 minutes, once a day for 1 week consecutive on a cotton pad followed
Active Comparator: essential oil of Rosmarinus officinalis 2
Inhalation of 2 drops of rosemary cineol essential oil for 5 minutes, for once a day for 1 week consecutive on a cotton pad followed
Other: rosemary1
oil essential

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
STROOP TEST
Time Frame: Cognitive tests were administered at the following stages: "Before the intervention (baseline), immediately after the intervention, and 1 week after the intervention."
Unit of measurement: time (seconds)
Cognitive tests were administered at the following stages: "Before the intervention (baseline), immediately after the intervention, and 1 week after the intervention."
Subteste Digits of the Test WAIS-III - (Wechsler Adult Scale)
Time Frame: Cognitive tests were administered at the following stages: "Before the intervention (baseline), immediately after the intervention, and 1 week after the intervention."

1a. Maximum raw score: 30

1b. Minimum raw score: 2
Cognitive tests were administered at the following stages: "Before the intervention (baseline), immediately after the intervention, and 1 week after the intervention."
Subtest Number and Letter Sequence of the WAIS-III Test - (Wechsler Adult Scale)
Time Frame: Cognitive test were administered at the following times: "Before the intervention (baseline), immediately after the intervention, and 1 week after the intervention."

1.0 Measurement Units: raw score 1a. Maximum raw score: 21

1b. Minimum raw score: 0
Cognitive test were administered at the following times: "Before the intervention (baseline), immediately after the intervention, and 1 week after the intervention."
Tower of London
Time Frame: Cognitive test were administered at the following times: "Before the intervention (baseline), immediately after the intervention, and 1 week after the intervention."

1.0 Measurement Units: raw score 1a. Maximum raw score: 46

1b. Minimum raw score: 0
Cognitive test were administered at the following times: "Before the intervention (baseline), immediately after the intervention, and 1 week after the intervention."
Token Test
Time Frame: Cognitive test were administered at the following times: "Before the intervention (baseline), immediately after the intervention, and 1 week after the intervention."

1.0 Measurement Units: raw score 1a. Maximum raw score: 36

1b. Minimum raw score: 0
Cognitive test were administered at the following times: "Before the intervention (baseline), immediately after the intervention, and 1 week after the intervention."
Corsi Blocks
Time Frame: Cognitive test were administered at the following times: "Before the intervention (baseline), immediately after the intervention, and 1 week after the intervention."

1.0 Measurement Units: raw score 1a. Maximum raw score: 30

1b. Minimum raw score: 0
Cognitive test were administered at the following times: "Before the intervention (baseline), immediately after the intervention, and 1 week after the intervention."
Hopkins Verbal Learning
Time Frame: Cognitive test were administered at the following times: "Before the intervention (baseline), immediately after the intervention, and 1 week after the intervention."

1.0 Measurement Units: raw score 1a. Maximum raw score: 0

1b. Minimum raw score: 36
Cognitive test were administered at the following times: "Before the intervention (baseline), immediately after the intervention, and 1 week after the intervention."

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Federal University of Paraíba

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 1, 2025

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

December 31, 2026

Study Registration Dates

First Submitted

April 13, 2026

First Submitted That Met QC Criteria

April 28, 2026

First Posted (Actual)

May 1, 2026

Study Record Updates

Last Update Posted (Actual)

May 1, 2026

Last Update Submitted That Met QC Criteria

April 28, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • 80434324.0.0000.5188

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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