The Science of Scent: How Your Sense of Smell Shapes Your Wellbeing

We don’t often think of our sense of smell as being that important; however, let me dismiss that misconception.

Our sense of smell, our olfactory system, is one of the oldest and most fundamental sensory systems we have. In many animals, it’s essential for communication, safety, and attraction. Even in humans, a newborn baby’s sense of smell is the most developed of all the senses, functioning at a level that supports survival and bonding. 

The Evolution of Scent

Modern humans don’t rely on smell as much as our ancient ancestors did because many tasks that once depended on scent are now handled by tools and technology.

·       Instead of smelling spoiled food, we use fridges and expiry dates.

·       Instead of detecting danger by scent, we rely on alarms and lighting.

·       Instead of using natural body odour for social cues, we use perfumes and deodorants.

However, that doesn’t mean smell is unimportant – far from it.

What Happens When We Smell Something?

When you inhale an aroma, tiny airborne molecules enter your nasal cavity and dissolve into the olfactory epithelium, a specialised patch of tissue high inside the nose. Here, the scent molecules bind to specific receptors and are converted into chemical signals, which trigger an electrical impulse. 

This signal travels to the olfactory bulb, which processes the information and sends it along the olfactory tract deep into the brain, ending in the Limbic System. While most other senses take multiple pathways through the brain before reaching their final processing centres, smell is unique: it follows a single, direct route.

What is the Limbic System?

The limbic system is found deep within the brain, almost in the center. This region is responsible for basic survival needs, including:

·       Hunger, thirst, temperature regulation

·       Instinctive reactions and emotional processing

·       Memory and automatic bodily functions via the autonomic nervous system and the endocrine (hormone) system.

Because smell feeds straight into these networks, a single scent can influence mood, trigger physiological responses, or unlock vivid memories. This is why a familiar aroma can suddenly transport you to another moment in your life.

The Chemistry of Essential Oils

Essential oils aren’t mystical; it’s chemistry meeting neurobiology. Different essential oils contain specific volatile compounds that activate different combinations of receptors, creating distinct neural ‘barcodes’:

·       Linalool in Lavender: Known to be sedative and calming

·       Menthol in Peppermint: Understood to be refreshing and energising.

Over the past few decades, modern analytical tools such as gas chromatography and mass spectrometry have allowed us to identify these compounds precisely. We can now link the traditional uses of essential oils to measurable biochemical properties rather than relying solely on anecdotal experience.

The Tisserand Heritage and Understanding

At Tisserand, we have over 50 years of experience in sourcing our essential oils. We have a panel that meets weekly to assess new batches and ensure we are only sourcing the best.

·       We look (or smell) for consistency of aroma, thickness, colour.

·       We check the country of origin, safety data sheets, and paperwork to ensure the essential oil is 100% pure.

Discover more about how we source our oils with integrity

Understanding how smell works shows just how deeply this sense is woven into our biology and everyday wellbeing. It is a direct line into the most instinctive parts of the brain, shaping how we feel, respond, and connect.

About Jo Kellett

Our essential oil expert, Jo Kellett TIDHA MIFPA CIMI, graduated from the Tisserand Institute of Holistic Aromatherapy in 1996. She returned to the college in 1999 as an Essential Oil Therapeutics Tutor, where she taught until the college closed. Jo runs a successful private Aromatherapy practice in Brighton, specialising in Women’s health. Jo is also an internationally published author and has lectured on the subject of Aromatherapy both in the UK and abroad.
For more information on Jo Kellett, check out her website or Instagram.