How Essential Oils Support Mood: The Brain–Breath Connection

A Rei Hirano Guide to Calm, Clarity and Emotional Balance

Essential oils are more than just beautiful scents. These concentrated plant extracts contain active compounds that can influence how we feel—helping us unwind, feel more grounded, and gently support our emotional wellbeing.

At Rei Hirano, we’re especially interested in how inhaling essential oils interacts with both the nervous system and the respiratory system. In simple terms: the way you breathe in aroma can affect your brain, your mood, and your stress levels.

This article explores:

• How essential oils may ease feelings of stress and low mood
• Why breathing in aroma is such a powerful delivery method
• What’s happening at a brain and body level (in easy language)
• How this science connects to your everyday aromatherapy rituals

⚠️ Important: Essential oils are a complementary wellness tool, not a replacement for professional care. If you’re experiencing depression, anxiety, or other mental health concerns, please speak with a qualified health professional.

What Are Essential Oils, Really?

Essential oils are highly concentrated aromatic extracts from plants—flowers, leaves, bark, peels and resins. They contain dozens (sometimes hundreds) of naturally occurring molecules that can:

• Influence mood and stress response
• Support relaxation or alertness
• Affect breathing patterns and heart rate
• Interact with various brain and body systems

You’ll often find them used in:

• Diffusers
• Roll-ons and pulse-point oils
• Massage blends
• Bath soaks and inhalation rituals

At Rei Hirano, we focus on blends that are calming, grounding and emotionally supportive, like lavender-led blends, citrus uplift blends, and floral mood-balancing blends.

How Essential Oils May Help With Mood, Stress and Emotional Balance

A growing body of research suggests that certain essential oils can help:

• Ease feelings of anxiety or nervousness
• Support relaxation and improved sleep quality
• Reduce perceived stress
• Support a more positive mood

Oils frequently studied for mood support include:

• Lavender – associated with calming, relaxation, and more settled sleep
• Bergamot & other citrus oils (orange, yuzu) – often linked with uplifted mood and reduced tension
• Chamomile – known for its soothing, comforting emotional profile
• Rose – supportive for the heart and mood, often used in emotional care
• Rosemary & sage family oils – sometimes associated with mental clarity and cognitive support
• Ylang-ylang – deeply floral and relaxing, used for inner calm and tension relief

These findings come from both human and animal studies, but the key takeaway for everyday life is simple:

Certain essential oils, especially when inhaled, appear to help the body move out of “fight or flight” and into a calmer, more balanced state.

Why Inhalation Is So Powerful

You can use essential oils in many ways—on the skin (diluted), in baths, or less commonly as oral preparations under professional guidance. But inhalation is the most common—and often the most effective—route for emotional and mood support.

When you inhale an essential oil:

1. Aroma molecules enter through the nose
2. They interact with the olfactory system (your sense of smell)
3. Simultaneously, some molecules travel down the respiratory tract into the lungs
4. From there, certain components can enter the bloodstream and reach the brain

This dual route—the nose–brain pathway and the lungs–blood–brain pathway—is what makes inhalation so interesting for mood support.

Route 1: The Smell Pathway (Olfactory System → Brain → Emotions)

Your sense of smell is directly plugged into the parts of the brain that deal with emotion, memory and stress responses.

What happens when you smell an essential oil?

1. Aroma molecules bind to specialised smell receptors high in the nasal cavity.
2. These receptors send electrical signals to the olfactory bulb in the brain.
3. From there, signals travel to regions such as:

• • The amygdala (emotional processing, especially fear and anxiety)
  • The hippocampus (memory)
  • The hypothalamus (hormones and stress response)

Because of this direct wiring, scent can:

• Trigger emotional memories
• Shift mood quickly
• Influence the stress response system (the hypothalamic–pituitary–adrenal, or HPA axis)

That’s why something as simple as turning on your Rei Hirano diffuser with a lavender-citrus blend can visually and emotionally “soften” the room.

Route 2: The Breath Pathway (Lungs → Bloodstream → Brain)

When you inhale, essential oil vapours also travel into the lungs, reaching tiny air sacs called alveoli. Here:

• Some lipid-loving (fat-soluble) components can cross into the blood
• From the bloodstream, they may cross the blood–brain barrier and reach specific brain regions

This is where essential oils may work more like classic pharmacology:

• Interacting directly with receptors (for example, GABA, serotonin or dopamine receptors)
• Modulating inflammation and oxidative stress
• Influencing circulation, heart rate and breathing pattern

The result can be a combination of:

• Psychological effects (how you feel emotionally)
• Physiological effects (what your body is doing—heart rate, breathing, blood pressure)

 

What’s Going on Inside the Brain? (Simplified Science)

You absolutely don’t need to know all the biochemistry to enjoy your oils—but if you’re curious, here’s what current research suggests essential oils may influence:

1. Mood Chemicals (Monoamines)

Certain essential oils seem to influence brain messengers like:

• Serotonin (5-HT) – linked to mood stability, calm and emotional resilience
• Dopamine (DA) – connected to motivation, pleasure, and reward
• GABA – the brain’s main calming neurotransmitter

For example, some animal and human studies suggest that inhaling specific oils or blends may:

• Increase serotonin levels or serotonin activity
• Support more balanced dopamine signalling
• Interact with GABA-related pathways, promoting relaxation

This doesn’t turn essential oils into antidepressant medications—but it does help explain why a calm blend can feel more than just “nice.”

2. Neurogenesis & Brain Nourishment (Neurotrophic Factors)

Modern neuroscience has shown that the brain can continue to create new neurons—especially in areas related to mood and memory, such as the hippocampus. Some research suggests that:

• Chronic stress can reduce neurogenesis (new brain cell growth)
• Certain treatments, including some antidepressants, can increase it
• Some essential oils may also support this process

One key protein in this story is BDNF (brain-derived neurotrophic factor), which supports neuron growth and plasticity. Some studies indicate that exposure to certain oils or blends may:

• Protect or boost BDNF levels
• Support healthier neuronal growth under stress

In everyday terms: this may be one way aromatherapy supports long-term mood resilience—although more research is needed.

3. Stress Hormones & the Neuroendocrine System

Your stress response is largely regulated by the HPA axis—a network that includes the brain and adrenal glands. When you’re under prolonged stress, cortisol (the main stress hormone) can stay elevated, affecting mood, energy, sleep, and more.

Some human and animal studies report that inhalation of certain essential oils (especially lavender, bergamot, and some mixed blends) can:

• Reduce salivary or blood cortisol levels
• Promote relaxation and a calmer nervous system
• Support more balanced cardiovascular responses (e.g. heart rate, blood pressure)

This aligns with what many people feel when they use lavender-heavy blends in a diffuser or massage oil:

A sense of “unwinding” both mentally and physically.

4. Oxidative Stress & Inflammation

Chronic stress, low mood and anxiety can be linked with increased:

• Oxidative stress (too many reactive oxygen species)
• Inflammation in the body and possibly in the brain

Several essential oils are known for their antioxidant and anti-inflammatory properties. While many of these studies are still early and often focus on other conditions (like skin or immune health), they suggest that:

• Essential oils may help neutralise oxidative stress
• They may influence inflammatory signalling molecules

Could this contribute to their mood-supportive effects? Possibly—and this is a key area for future research.

What Does This Mean for Your Rei Hirano Rituals?

You don’t need a lab coat to enjoy the benefits. Here’s how you can translate the science into daily practice.

1. Create a Breathing Ritual, Not Just a Scented Room

Instead of just turning on a diffuser in the background:

• Sit or lie down comfortably
• Take slow, deep breaths through the nose
• Gently lengthen your exhale

This way you’re using both sides of the mechanism: the olfactory pathway and the respiratory pathway.

2. Choose Oils by Mood

• For calm & emotional comfort:
  Lavender, chamomile, rose, ylang-ylang, neroli
• For uplift & motivation:
  Sweet orange, bergamot, lemon, grapefruit, rosemary
• For grounding & safety:
  Cedarwood, frankincense, patchouli (often blended with florals or citrus)

Rei Hirano blends are crafted with this emotional layering in mind—pairing calming florals with soft woods or bright citrus to balance comfort and clarity.

3. Layer Your Sensory Environment

Combine aromatherapy with:

• Soft lighting (warm lamps, salt lamps, candles)
• Gentle sound (white noise, ambient music, nature sounds)
• Tactile comfort (weighted blankets, soft throws, comfortable loungewear)

This multi-sensory approach taps into sight, sound, touch and smell—all working together to guide the brain into a calmer state.

A Gentle Reminder About Mental Health

While essential oils and aromatherapy can be wonderful supporting tools:

• They are not a cure for depression, anxiety, or other mood disorders
• They should not replace medical advice, therapy, or prescribed medication
• They work best as part of a broader self-care and treatment plan

If you’re struggling with your mental health, please reach out to a doctor, psychologist, counsellor, or appropriate support service in your area. You deserve proper care.

The Future of Essential Oils & Mood: Where Research Is Heading

Scientists are still exploring:

• Which specific plant compounds (like linalool, limonene, etc.) have the strongest mood benefits
• How different blends interact with brain receptors and mood circuits
• The best ways to standardise essential oils in clinical research

As this field grows, we expect to see more targeted use of essential oils alongside conventional care—especially for stress-related or mood-related challenges.

At Rei Hirano, we’re inspired by this developing science. Our goal is to translate it into beautiful, everyday rituals so you can experience the benefits in a simple, accessible, and luxurious way at home.

Explore Mood-Supportive Aromatherapy with Rei Hirano

Discover our curated range of:

• Calming diffuser blends for evening wind-down
• Daytime uplift blends for clarity and focus
• Bath and body rituals to support nervous system soothing
• Bedroom aromatherapy designed to pair with deeper, more restorative rest

Your breath is with you all day.
With the right aroma, it can become one of your most powerful tools for emotional balance.