IFA Logo


Essential Oil Aroma, Subjective Stress and Diurnal Cortisol Secretion in

Healthy Adults

A single blind, placebo controlled, cross over study


As the authoritative body for aromatherapy, we wanted to invest in research that kept the essential oils active throughout the duration of the trials, to establish empirical evidence of their effectiveness. Previous studies on essential oils have not kept the essential oil active, subjecting it to oxygen and sunlight which quickly kills the active ingredients, so previous findings to date have not been accurate. That is until now.

We chose the subject of chronic stress as we wanted to establish unequivocally, if essential oils can have a long-term impact rather than just lowering stress levels for a small amount of time in response to an immediate stressor. In the past, previous studies have only investigated acute effects of stress with the impact of a single exposure of an essential oil sniffed over 10, 20 or 30 minutes once. There have been many studies that have identified the effects of massage on stress but none on the effects of essential oils on stress alone using such a rigorous research protocol. With mental health issues acutely on the rise, continued activation of the stress response can result in negative, physical, behavioral and psychological symptoms, which is why this research is so pertinent.

Another unique aspect of this research is that we will be comparing the difference in effect between CO2 and traditionally obtained essential oils, which has never been tested before. The ramifications of the results of this third trial have the potential to radically change the industry.

Ultimately, this pioneering research aims to further validate the profession we present.  ​​​​​


The International Federation of Aromatherapists (IFA)


The University of Northumbria undertook three research trials on behalf of the IFA. Headed by Dr Mark Moss, head of the Department of Psychology and Professor of Psychobiology Mark Wetherell, lead for the Health and Wellbeing research cluster.


The IFA appointed Northumbria University to undertake three studies to determine whether essential oils can reduce stress levels within people using saliva and hair samples to determine cortisol levels, the biological marker of stress, and therefore stress levels. The IFA through decades of extensive oil knowledge, created a blend using five essential oils that are ‘known’ to decrease stress and wanted to see if this information was correct using scientific research methods.


The aroma line (orange line) indicates how essential oils affects diurnal cortisol levels. As this suggests, cortisol levels upon waking are a lot lower than baseline and after the spike 45 minutes after waking, diurnal cortisol levels dramatically drop throughout the day till bedtime. 


No other body of research has tested essential oils over a long period of time in the lab and in real life.

The protocol involved participants sniffing the essential oils over an eight-week period. Saliva and hair samples were taken at the beginning and end of the study to test for diurnal cortisol secretion levels, the biological marker of stress and therefore stress levels. Questionnaires were given to participants at the beginning, during, and at end the research period. Research participants were selected across the age range and had equal proportion of Female and Male participants.

Two research protocols were undertaken in the first study:

  1. The first protocol involved a study undertaken in the laboratory at the Northumbria University with 100 participants using saliva to test cortisol levels over 8 weeks. 50 were given the essential oil blend and 50 were given the placebo. They employed the use of a perceptible placebo to reduce the potential impact of expectancy effects on subjective measures as the saliva and hair cortisol level tests are a reliable marker of stress levels within an individual and is independent therefore of expectancy effects.
  2. The second protocol also involved a ‘live’ study whereby therapists submitted volunteers who used the oils at home themselves, answered questionnaires online and hair samples were taken at the beginning and at the end.​​​​​​

This is phenomenal, not only are people waking up less stressed, sniffing essential oils once a day helped keep their cortisol levels down, no matter what they were facing till bedtime. People slept better and awoke more refreshed.

Preorder the Blend 

More details to follow ...