Why Some Aromas Soothe the Nervous System While Others Quietly Escalate Stress

Walk into a hotel lobby, your childhood home, or even a friend’s kitchen, and you will know how you feel within seconds. Before you see furniture, lighting, or people, your brain has already formed its first impression.

Scent is one of the fastest ways the environment communicates with the nervous system.

This is why the scent of home-cooked food can make you feel safe.

It is why the smell of a familiar pillow can help you sleep.

And it is why intense, dense aromas in public spaces can sometimes make you feel unsettled, even when the intention is luxury or relaxation.

Across neuroscience and environmental psychology, research consistently shows that scent can either stabilise the nervous system or heighten emotional activation [1,2]. The difference depends on both what the scent is and how intense it is.

Understanding this relationship is critical for hospitality, workplace design, wellbeing environments, and personal performance.

Why Scent Influences Emotion So Quickly

The direct pathway to the limbic system

Smell is the only sensory channel with a direct connection to the amygdala and limbic system, bypassing the brain’s usual filters.

This is why:

• The smell of your childhood home can instantly trigger comfort
• The smell of a favourite meal can lower stress
• The smell of your own bed on a pillow can improve sleep onset
• Strong or unfamiliar scents can trigger alertness even before you consciously notice them
  
  

The olfactory system evolved as an early warning mechanism. Potent volatile compounds often signal risk: smoke, decay, irritants.

The brain still reacts to intensity as if it must decide: “Am I safe?”

This is why overly strong scents, even pleasant ones, can increase sympathetic activation and emotional tension [1,3].

Comfort Scents: Why “Smells Like Home” Matters

The biology of familiarity and safety

Familiar scents have a unique ability to signal safety because they are tied to autobiographical memory. Studies show that well-known scents:

• Reduce amygdala activation
• Lower heart rate
• Increase parasympathetic tone
• Increase perceived emotional safety [8]
  

This is why:

The smell of fresh bread, coffee, or warm spices often feels grounding
The aroma of clean laundry can create calm
Certain cultural food scents evoke emotional security
People sleep better on pillows that smell like home or a partner

The scent of a familiar pillow is one of the strongest examples.

Research shows that sleep quality improves when people sleep on a pillow carrying the scent of a partner or familiar home environment, because the brain interprets the aroma as “safe to switch off” [9,10].

This is environmental design at the deepest biological level, which is why we suggest that people pack their pillowcases. 

Calming Aromas vs Stimulating Aromas

What science tells us

Scents that calm 

These scents contain volatile compounds shown to activate calming pathways, lower cortisol, or increase vagal tone:

• Lavender, bergamot, chamomile (linalool, linalyl acetate)
• Green tea and white tea profiles (soft aldehydes supporting clarity)
• Hinoki, cedar, and gentle woods (alpha pinene)
• Mild vanilla, warm light baking notes, fresh linen profiles

• Jasmine and neroli (benzyl acetate, nerolidol)

They induce calm because they align with biological signals of safety and familiarity [8,10].

Scents that stimulate

These tend to raise alertness or sympathetic activation:

• Sharp mint, menthol, or camphor
• Strong spices like clove or cinnamon (eugenol, cinnamaldehyde)
• Heavy musks, dense florals, or thick synthetic fragrances
• Smoky, resinous, or overly complex aromatics

Again, these are not “bad”. They simply push the nervous system toward alertness. Strategic use is where the magic lies. 

Great for a gym. Poor for a hotel lobby or bedtime.

The Hidden Factor: Intensity Overrides Intent

Why strength matters more than the note itself

Environmental psychology shows that if a scent is too strong, the body often interprets it as:

• Reduced airflow
• Reduced cleanliness
• Higher chemical load
• Environmental clutter
• A need for vigilance [4,11]

This happens even with “pleasant” aromas.

This is why a subtle smell of cookies can feel comforting, but a heavy cloud of synthetic vanilla can feel suffocating.

Intensity shapes emotional clarity more than the specific scent.

What This Means for Hospitality, Workplaces, and Everyday Life

Whether designing a hotel, a corporate space, a spa, or even your home, scent must align with the physiological intention of the space.

For example:

• Transition spaces (lobbies, corridors, reception areas) benefit from light citrus, green tea, soft botanicals.
• Recovery spaces (spa rooms, suites, bedrooms) require subtle, familiar, calming notes like lavender, hinoki, or linen clean scents.
• Performance spaces (work areas, gyms) can use crisp mint or bright citrus to enhance alertness.
• Sleep environments should maximise familiarity: personal pillow scent, light botanical notes, and extremely low intensity.

When scent conflicts with the environment's purpose, the nervous system receives mixed signals.

And mixed signals reduce performance, recovery, and comfort.

How This Fits Into Human Performance Protocols

Arousal state management is the foundation of modern performance.

Scent is merely one environmental lever. But an easy one to manage. 

Light, behaviour, temperature, workload, and supplementation are others.

When environments overstimulate the nervous system with bright lights, noise, synthetic scent, and travel stress, people need tools that help them rebalance.

Environment and supplementation are not competitors and just as the HMN24 range is biologically aligned all other points of stimulus should also follow suit.

They are part of the same biological ecosystem.

The smells we trust shape how we feel before we think

We often believe our mood is driven by thoughts, motivation, or willpower. But the nervous system makes many decisions before we are conscious of them.

• The scent of home cooked food can calm you because it signals safety.
• A familiar pillow can improve sleep because it signals belonging.
• A strong commercial fragrance can elevate stress because it signals intensity.
• A light botanical scent can ease tension because it mimics natural cues.

When we understand how scent shapes physiology, we design better spaces, improve sleep, support recovery, and enhance performance.

This is the philosophy we apply at HMN24: aligning tools, environments, and behaviours to support a healthier, more consistent you.

References

1. Elman, I., and Borsook, D. (2018). Threat response system. Frontiers in Psychiatry, 9, 1 to 14.

2. Owens, A., Allen, M., Ondobaka, S., and Friston, K. (2018). Interoceptive inference in sensory processing. Neuroscience and Biobehavioral Reviews, 90, 174 to 183.

3. Pang, C., Tu, Y., Chou, F., and Chang, S. (2024). Aromatherapy and stress. Journal of Clinical Nursing, 34, 1000 to 1012.

4. Bartczak Szermer, D., Szymanski, L., and Stankiewicz, W. (2016). Psychoneuroimmunology of environmental stress. Central European Journal of Immunology, 2, 209 to 216.

5. Dopfel, D., Perez, P., Verbitsky, A., Bravo-Rivera, H., Ma, Y., and Zhang, N. (2018). Individual variability in scent driven stress responses.

6. Kao, W., Hsiang, C., Ho, S., Ho, T., and Lee, K. (2018). Volatile compounds and sensory intensity. Molecules, 23, 2969.

7. Hou, W., Feng, J., Sun, Y., Chen, X., and Wei, J. (2024). Chemical composition of aromatics and nervous system activity. Frontiers in Pharmacology, 15, 1357381.

8. Liu, Y., Dong, Y., Wang, X., Huang, Y., Wu, F., and Wang, B. (2025). Lavender aromatherapy and autonomic balance. Frontiers in Pharmacology, 16, 1584998.

9. McBurney, D., Balaban, C., Christopher, D., and Harvey, C. (1997). The influence of odour on perceived sleep quality. Physiology and Behavior, 62, 321 to 327.

10. Biegler, R., Weiss, D., and Konig, S. (2017). Familiar scents and sleep depth. Journal of Sleep Research, 26, 629 to 636.

11. Chen, X., Wang, C., He, Q., Feng, J., and Liu, Y. (2022). Environmental aroma intensity and perceived air quality. Molecules, 27, 4528.