The Top Essential Oils For Mood Enhancement And Mental Clarity

The Top Essential Oils for Mood Enhancement and Mental Clarity

Consistent stress, racing thoughts, and daily demands can hijack our emotional well-being. In a world that rarely hits pause, many individuals are seeking natural allies to balance their minds and uplift their spirits. Enter essential oils: concentrated essences distilled from plants, revered for centuries for their aromatic and therapeutic properties. When harnessed correctly, these fragrant extracts can help soothe frayed nerves, sharpen focus, and foster a sense of calm that lingers long after the scent has dissipated. In this article, we’ll explore the most potent essential oils for mood enhancement and mental clarity, how they work, and practical tips for integrating them into your daily routine.

Why Essential Oils? Understanding Mood Enhancement and Mental Clarity

Essential oils are highly concentrated plant extracts that capture the “essence” of a plant’s fragrance and therapeutic compounds. From the rolling lavender fields of Provence to the citrus groves of Sicily, these oils have been employed in holistic traditions for millennia—used in religious ceremonies, healing rituals, and personal care.

Mood Enhancement vs. Mental Clarity

Mood enhancement refers to the lifting of emotional states, such as calmness, happiness, or relaxation. Think of it as an emotional “tune-up.”
Mental clarity involves sharpening cognitive processes, such as focus, alertness, and memory recall—akin to wiping fog off a window.

Although the distinction exists, many essential oils share similar effects. For instance, a fragrance that soothes anxiety might also quiet distracting thoughts, thereby improving concentration.

When selecting essential oils for mood and clarity, it’s crucial to recognize that individual responses can vary. What sparks alertness in one person might induce relaxation in another. However, scientific studies and anecdotal evidence converge on several oils that consistently deliver results.

How Essential Oils Influence Brain Function and Emotions

Aromatherapy’s potency largely stems from the intimate connection between our olfactory system (sense of smell) and the limbic system—our brain’s emotional center. Here’s what happens when you inhale an essential oil:

Olfactory Reception: Sensitive receptors in the nasal cavity pick up aromatic molecules.
Neural Signaling: Signals travel along the olfactory nerve to the olfactory bulb, which interfaces directly with the amygdala (emotional processing) and hippocampus (memory).
Neurochemical Release: Certain essential oils can trigger the release of neurotransmitters like serotonin, dopamine, or GABA, which play pivotal roles in mood regulation and cognition.

For example, inhaling lavender has been shown to increase gamma-aminobutyric acid (GABA) activity in the brain, promoting relaxation and reducing anxiety. Conversely, peppermint can increase alertness by stimulating areas of the brain associated with focus and arousal.

Pro Tip: Since each individual’s biochemistry is unique, take note of how a specific oil affects you. Keep a journal for a week, recording which scents uplift, calm, or focus you best.

Criteria for Choosing High-Quality Essential Oils

Not all essential oils are created equal. To ensure potency and purity, consider the following criteria when purchasing:

Botanical Name & Origin:

Look for Latin binomial labels (e.g., Lavandula angustifolia rather than just “lavender”).
Knowing the origin helps gauge quality; for instance, true French lavender from Provence often has a more nuanced profile than generic blends.

Method of Extraction:

Steam Distillation: Most common for flowers, leaves, and wood.
Cold Pressing: Typical for citrus peels (e.g., lemon, bergamot).
Solvent extraction or CO₂ extraction can yield aromatic “absolute” but may contain trace solvents.

Purity & Additives:

Choose 100% pure essential oils—no preservatives, no synthetic fragrances.
Avoid the term “fragrance oils,” which are often synthetic replicas.

Third-Party Testing:

GC/MS (Gas Chromatography/Mass Spectrometry) reports confirm chemical constituents and purity levels.
Reputable brands often publish these reports online or include them upon request.

Packaging:

Essential oils are light- and heat-sensitive. Amber or cobalt blue glass bottles with tight caps are best.
Avoid plastic bottles, which can leach chemicals over time.

Price Point:

Extremely cheap oils (e.g., under $5 for a 10-ml bottle) are often diluted or adulterated.
Conversely, exorbitantly priced oils may carry a premium brand markup. Seek a balance—quality doesn’t always mean break-the-bank.

Top Essential Oils for Mood Enhancement

Oil	Category	Key Benefits	Suggested Application
Lavender	Mood Enhancement	Reduces anxiety, promotes relaxation, aids sleep	Diffuse, topical (diluted), bath
Bergamot	Mood Enhancement	Reduces stress, uplifts mood	Diffuse, topical (diluted), direct inhalation
Ylang Ylang	Mood Enhancement	Reduces stress, induces euphoria, lowers blood pressure	Bath, direct inhalation, diffuse
Clary Sage	Mood Enhancement	Eases depression, balances hormones reduces stress	Topical (diluted), aromatic, steam inhalation
Chamomile	Mood Enhancement	Calms tension, eases insomnia, reduces irritability	Diffuse, topical (diluted), tea infusion
Peppermint	Mental Clarity	Enhances focus, reduces mental fatigue	Direct inhalation, diffuse, topical (diluted)
Rosemary	Mental Clarity	Improves memory, boosts alertness	Diffuse, inhaler, topical (diluted)
Lemon	Mental Clarity	Elevates mood, improves attention	Diffuse, topical (diluted), room spray
Frankincense	Mental Clarity	Promotes focus, increases alpha wave activity	Diffuse, topical (diluted), roll-on blend
Vetiver	Mental Clarity	Grounds mind, improves working memory	Topical (diluted), diffuse, misting spray

Lavender (Lavandula angustifolia)

Lavender is arguably the most well-researched oil for anxiety relief and mood stabilization. Its gentle, herbaceous floral aroma calms the nervous system by increasing GABA neurotransmitter activity, which counteracts overexcitation in the brain.

Benefits:

Reduces symptoms of anxiety and mild depression
Promotes deeper sleep
Eases tension headaches

Application Methods:

Diffuser: Add 5–8 drops to a diffuser 30 minutes before bedtime.
Topical (Diluted): Mix two drops with one teaspoon of carrier oil (e.g., jojoba) and apply to the temples or wrists.
Bath: Combine 5–7 drops with a tablespoon of bath salts for a relaxing soak.

Research Spotlight

A 2017 randomized controlled trial found that pregnant women who inhaled lavender for two weeks reported significantly lower anxiety scores than those in the control group.

Bergamot (Citrus bergamia)

Bergamot oil’s bright, citrusy, floral scent possesses dual properties: it is both stimulating and calming. Its unique chemistry allows it to reduce cortisol levels (the primary stress hormone) while simultaneously uplifting mood.

Benefits:

Decreases cortisol, reducing stress and tension
Improves feelings of well-being
Antidepressant and anxiolytic properties

Application Methods:

Aromatic: 4–6 drops in a diffuser during mid-afternoon “slump” periods.
Massage Blend: Mix three drops with 10ml of carrier oil and apply to the neck and shoulders.
Inhalation: Place 1 drop on a cotton ball and inhale deeply for 1–2 minutes when feeling overwhelmed.

Research Spotlight

A study involving 60 individuals with mild anxiety showed that inhaling bergamot for 60 minutes significantly lowered anxiety scores compared to controls.

Ylang Ylang (Cananga odorata)

Ylang Ylang possesses an intensely sweet, floral aroma often associated with romance. Its molecular components—benzyl acetate and linalool—can reduce blood pressure and heart rate, inducing deep relaxation without sedation.

Benefits:

Eases stress and emotional tension
Lowers heart rate and blood pressure
Enhances feelings of joy and euphoria

Application Methods:

Bath: 5 drops mixed with Epsom salts for a calming evening ritual.
Inhalation: Add 1–2 drops to a handkerchief for occasional sniffing throughout the day.
Diffuser: 5 drops in the bedroom diffuser at night to promote restful sleep.

Research Spotlight

In a small 2015 study, participants who inhaled ylang-ylang exhibited reduced heart rate variability, indicating a shift toward parasympathetic (rest-and-digest) dominance.

Clary Sage (Salvia sclarea)

Clary Sage is prized for its musky-herbaceous aroma. Its sclareol component mimics estrogenic activity, which may explain why it’s often used to ease symptoms of PMS and hormonal imbalances.

Benefits:

Reduces feelings of depression, especially hormonal-related
Relieves stress and improves mood
Balances emotions

Application Methods:

Topical (Diluted): Mix two drops with one teaspoon of coconut oil and apply to the lower abdomen or wrists.
Aromatic: 4 drops in a diffuser during times of high emotional stress.
Steam Inhalation: Add two drops to a bowl of hot (not boiling) water, cover with a towel, and inhale for 5 minutes.

Research Spotlight

A study on 50 women with PMS found that inhaling clary sage for 30 minutes daily over two menstrual cycles reduced reported anxiety and depressive symptoms.

Chamomile (Matricaria chamomilla or Chamaemelum nobile)

Chamomile’s gentle, apple-like fragrance promotes tranquility and is often used to combat insomnia and nervous tension. Its active constituents, such as apigenin, bind to benzodiazepine receptors in the brain, fostering relaxation.

Benefits:

Eases insomnia and promotes restful sleep
Calms nervous tension and irritability
Soothes digestive discomfort linked to stress

Application Methods:

Diffuser: 5 drops in the diffuser an hour before bedtime.
Topical (Diluted): 2 drops blended with almond oil, massaged onto the solar plexus.
Tea Infusion: Though not an essential oil application, drinking chamomile tea complements its mood-enhancing effects.

Research Spotlight

A 2016 clinical trial involving 60 adults with generalized anxiety disorder (GAD) showed that 1,500 mg of chamomile extract daily significantly reduced GAD symptoms after eight weeks.

Top Essential Oils for Mental Clarity

Peppermint (Mentha × Piperita)

Peppermint is a powerhouse when it comes to alertness and cognitive performance. Its invigorating menthol-rich scent can stimulate the hippocampus and frontal lobe—regions implicated in memory and decision-making.

Benefits:

Enhances focus, concentration, and memory recall
Reduces mental fatigue and brain fog
Uplifts mood with its energizing aroma

Application Methods:

Inhalation: Place 1 drop under your nose or in your palms, cup your hands, and inhale deeply for immediate alertness.
Diffuser: 3–5 drops during study sessions or long meetings.
Topical (Diluted): Mix one drop with one teaspoon of fractionated coconut oil; apply to the temples or back of the neck for sustained focus.

Research Spotlight

A study of 144 participants found that those who inhaled peppermint oil had faster and more accurate math test performance, indicating enhanced cognitive function.

Rosemary (Rosmarinus officinalis)

Rosemary’s herbaceous, uplifting aroma is famous for sharpening mental faculties. It is rich in the compound 1,8-cineole, which has been linked to improved memory, cognitive speed, and alertness.

Benefits:

Boosts short-term memory and recall
Improves concentration and mental stamina
Relieves mental fatigue

Application Methods:

Diffuser: 5 drops in the morning or during intense work periods.
Inhaler Stick: Fill an inhaler stick with five drops; inhale before studying or working.
Topical (Diluted): 2 drops in 1 teaspoon of jojoba oil, massaged onto the wrists or chest.

Research Spotlight

A 2012 study of 28 adults demonstrated that sniffing rosemary oil while performing mental arithmetic tasks improved speed and accuracy compared to a control group.

Lemon (Citrus limon)

The lemon essential oil has a bright, uplifting scent that cuts through the mental haze. Its high limonene content is known to enhance mood and cognitive function, making it ideal for morning routines.

Benefits:

Elevates mood and reduces stress
Improves attention span and memory
Detoxifies the mind and body

Application Methods:

Diffuser: 5–6 drops first thing in the morning or during the mid-afternoon slump.
Topical (Diluted): 1–2 drops in 1 teaspoon of carrier oil, massaged onto the upper back and shoulders.
DIY Room Spray: Combine 10 drops of lemon oil with two oz. Of distilled water in a spray bottle for an instant pick-me-up.

Research Spotlight

A 2014 crossover trial in which participants were exposed to lemon scent showed significant improvements in mood scores and cognitive performance compared to controls.

Frankincense (Boswellia serrata)

Frankincense’s warm, resinous aroma promotes deep introspection and mental calm. It modulates brain wave activity, increasing alpha waves (associated with relaxed focus) and decreasing beta waves (tied to stress and anxiety).

Benefits:

Enhances meditation and mindfulness practice
Reduces anxious thoughts, promoting mental steadiness
Supports immune health, indirectly benefiting cognitive function

Application Methods:

Diffuser: 4-5 drops in a quiet space during meditation or study.
Topical (Diluted): 2 drops in 1 teaspoon of carrier oil, massaged onto the palms; cup hands and inhale between work sessions.
Roll-On Blend: Combine five drops of frankincense and five drops of lavender in a 10-ml roll-on bottle filled with fractionated coconut oil; apply to wrists as needed.

Research Spotlight

A 2016 EEG study found that inhaling frankincense increased alpha wave activity by up to 37%, indicating enhanced states of relaxation and focus.

Vetiver (Vetiveria zizanoides)

Vetiver is often referred to as the “oil of tranquility” for its deeply grounding, earthy aroma. It has a balancing effect on brain waves—inducing slow alpha waves that help with both relaxation and focused attention.

Benefits:

Reduces nervous tension and anxiety
Enhances mental focus and clarity, especially when feeling scattered
Promotes restful sleep without grogginess upon waking

Application Methods:

Topical (Diluted): 2 drops in 1 teaspoon of almond oil, massaged onto the lower back or feet.
Diffuser: 3–4 drops at night to calm a restless mind.
Misting Spray: Combine eight drops of vetiver with 2 oz. Fill a spray bottle with distilled water and spritz it in your workspace for mid-day grounding.

Research Spotlight

In a small 2018 trial, participants who inhaled vetiver oil during cognitive tasks demonstrated improved working memory and mental flexibility compared to those in unscented controls. 12

Methods of Application: Maximizing Benefits Safely

Choosing the correct application method can make or break your essential oil experience. Here are the most effective techniques for mood and clarity:

Diffusion (Aromatic Method)

Why: Disperses microdroplets of oil into the air, allowing for continuous inhalation.
How: Use an ultrasonic diffuser with 100–200 ml of water. Add 4–8 drops of your chosen oil(s). Run intermittently—e.g., 30 minutes on, 30 minutes off—to prevent olfactory fatigue.
Ideal For: Shared living spaces, nighttime relaxation, or morning pick-me-ups.

Direct Inhalation

Why: Provides a quick, intense burst of aroma.
How: Place 1 drop on a tissue or cotton ball, hold 2–3 inches from nostrils, and inhale deeply for 30–60 seconds. Alternatively, use personal inhaler sticks (portable, discreet).
Ideal For: On-the-go stress relief, sudden anxiety episodes, or mid-meeting focus boosts.

Topical (Diluted) Application

Why

Most oils contain therapeutic constituents that can be absorbed through the skin, providing localized or systemic benefits.

How

Always dilute essential oils in a carrier oil (e.g., jojoba, coconut, sweet almond) at appropriate ratios:

Adults: Use a 1% dilution for everyday use (6 drops of essential oil per 10 mL carrier).

Targeted Relief (e.g., tension headaches): 2–3% dilution (12–18 drops per 10 ml carrier).

Ideal For: Headaches (temples), muscle tension (neck/shoulders), or pulse points for sustained aroma throughout the day.

Baths and Foot Soaks

Why: Warm water opens pores, enhances absorption, and promotes deep relaxation.
How: Add 5–7 drops of essential oil to a tablespoon of Epsom salts or milk, then stir into a warm bath. For foot soaks, combine 3–5 drops with a tablespoon of salt in a basin of warm water.
Ideal For: Evenings when winding down or when aching muscles accompany mental stress.

Aromatic Sprays & Room Mists

Why: Provides a refreshing burst of scent for an entire room or linens.
How: Fill a 4-oz spray bottle with distilled water, add 10–15 drops of chosen essential oil(s), and shake well before each use. Optionally, include a teaspoon of witch hazel or vodka to help disperse oils.
Ideal For: Refreshing bedding, revitalizing a stuffy office, or creating a welcoming environment before guests arrive.

Roll-On Blends

Why: Convenient, portable, and mess-free.
How: Use 10-ml roll-on bottles, fill ¾ complete with carrier oil, and add 10–12 drops of essential oil. Secure the roller ball and cap, and shake well.
Ideal For: Daily emotion support, taking to work or traveling, discreet anxiety relief.

Safety Guidelines and Precautions

When wielded properly, essential oils are safe and effective. However, misuse can lead to adverse reactions. Below are key precautions to heed:

Dilution Is Non-Negotiable

Always dilute essential oils in a carrier oil before applying them to the skin.

General dilution ratios:

1% (Daily Use): 6 drops of oil per 10 ml carrier (approximately 2% for targeted issues like headaches).
2–3% (Short-Term Use): 12–18 drops per 10 ml carrier.

Patch Test First

Apply a small diluted drop to the inner forearm; cover with a bandage for 24 hours.
If redness, itching, or burning occurs, discontinue use immediately.

Photosensitive Oils

Citrus oils (e.g., bergamot, lemon, lime, grapefruit) can cause phototoxicity, leading to burns or hyperpigmentation when exposed to direct sunlight for 12–24 hours after application.
Avoid sun exposure or UV rays on areas treated with citrus oils.

Pregnancy & Nursing

Some oils are contraindicated during pregnancy and breastfeeding (e.g., clary sage, rosemary, vetiver in high concentrations).
Always consult a qualified aromatherapist or healthcare professional before using essential oils during pregnancy.

Children & Elderly

Use reduced dilutions (0.5–1%) for children over age 2; avoid peppermint, rosemary, and eucalyptus for children under six without professional guidance.
Elderly individuals may have thinner or more sensitive skin; start with a 0.5% dilution and monitor for skin reactions.

Quality Assurance

Keep essential oils out of reach of children and pets—some oils can irritate or be toxic if ingested.
Store bottles away from heat, light, and humidity—in a cool, dark cabinet.
Replace oils after 1–2 years (citrus oils shorter, woody oils longer) for maximum efficacy.

Drug Interactions & Medical Conditions

Certain oils (e.g., lavender, frankincense) may have mild blood-thinning properties. If you’re on anticoagulant medications, exercise caution.
Those with epilepsy, high blood pressure, or other chronic conditions should consult healthcare professionals before extensive essential oil use.

Integrating Essential Oils into Your Daily Routine

For maximal impact, consistency is key. Below is a sample daily regimen optimized for both mood elevation and cognitive clarity:

Morning Ritual: Uplift & Focus

Diffuser Blend (Morning Kickstart):

3 drops peppermint
3 drops rosemary
2 drops lemon
Run for 30 minutes as you shower, prepare breakfast, or begin work.

Topical Pulse Point (On-the-Go):

In a 10-ml roller bottle, combine five drops of peppermint and five drops of lemon, topped with fractionated coconut oil.
Apply to wrists and temples during your commute or first meeting.

Midday Reset: Banish the “Slump”

Inhalation Booster:

Keep a personal inhaler stick filled with bergamot and frankincense (4 drops each). Inhale deeply for 30–60 seconds when attention wanes around 2–3 PM.

Mindful Break (5 Minutes):

Diffuse four drops of lavender mixed with two drops of vetiver in a small desktop diffuser. Close your eyes, breathe deeply, and let the blend reset your stress response.

Evening Wind-Down: Stress Relief

Bath or Foot Soak:

Warm bath: 5 drops chamomile + 3 drops lavender + 2 drops ylang-ylang, stirred into 1 cup Epsom salts.
If bathing isn’t possible, a foot soak with the same proportions in a basin of warm water can yield similar relaxation.

Pre-Bedtime Diffuser:

4 drops lavender + 2 drops clary sage. Run the diffuser at low intensity for 20 minutes while you journal or read.

Weekend Self-Care: Deep Emotional Release

DIY Massage Oil:

For days when anxiety feels overwhelming, mix eight drops of bergamot + 4 drops of clary sage + 8 drops of jojoba oil in a small bottle.
Massage onto shoulders, neck, and back, focusing on areas where you hold tension.

Meditation & Reflection:

During meditation, add three drops of frankincense + 2 drops of vetiver to your diffuser.
As you meditate, focus on slow, rhythmic breathing. Let each exhale release worry, and each inhale invites clarity.

Conclusion

Essential oils offer a compelling, natural approach to enhancing mood and sharpening mental clarity. From the gentle floral notes of lavender that soothe frayed nerves to the invigorating peppermint that banishes mental fog, each oil brings its symphony of benefits. By selecting high-quality oils, applying them safely, and integrating them purposefully into your routine, you can craft an aromatic toolkit for well-being.

Remember: individual responses vary. What electrifies one person might lull another to sleep. Experiment with single oils and synergistic blends to discover your personal “aroma signature.” Keep a journal of your experiences, noting which scents spark joy, quell anxiety, or sharpen concentration. Over time, you’ll develop a personalized protocol—an aromatic roadmap—to achieve your optimal mental and emotional state.

Embrace the journey. Breathe deeply. Let nature’s purest essences guide you toward a calmer mind and a more explicit focus.

FAQs

Can essential oils improve my mood?

Yes. Multiple studies have revealed that inhaling certain essential oils, such as lavender, bergamot, or ylang-ylang, can modulate neurotransmitters (like GABA and dopamine), leading to measurable reductions in anxiety and improvements in mood. Individual responses vary, so experiment to see which oil resonates with you.

Which essential oil is best for mental clarity?

Peppermint and rosemary top the list. Peppermint’s menthol content stimulates the hippocampus and frontal lobes, promoting focus and alertness. Rosemary’s 1,8‐cineole similarly enhances memory and cognitive performance. Using these oils—especially via diffusion or direct inhalation—can help clear mental fog.

How should I store essential oils to maintain potency?

Keep oils in amber or cobalt blue glass bottles with tight caps. Store them in a cool, dark place away from direct sunlight, heat sources, and humidity (e.g., a cabinet or drawer). Proper storage extends shelf life: citrus oils last ~1 year, while woody oils can remain effective for up to 3 years.

Are there any side effects of using essential oils?

Potential side effects include skin irritation or allergic reactions—always perform a patch test before topical use. Citrus oils can cause phototoxicity if skin is exposed to sunlight within 12–24 hours. People with certain medical conditions (like epilepsy or high blood pressure) should consult a healthcare professional. Pregnant or nursing women must exercise extra caution, as some oils can affect hormone levels.

Can I blend multiple essential oils for synergistic effects?

Absolutely. Blending oils can amplify their therapeutic profile. For example:

Relaxing Nighttime Blend: 4 drops lavender + 2 drops ylang ylang + 2 drops vetiver.
Energizing Work Blend: 3 drops peppermint + 3 drops lemon + 2 drops rosemary.
Stress Relief Blend: 3 drops bergamot + 3 drops frankincense + 2 drops chamomile.
Ensure you adjust total drops based on dilution guidelines, and always test for personal sensitivity.

How long before I notice results from using essential oils?

Many people report almost immediate effects—especially with potent oils like peppermint or lavender inhaled directly. When using diffusion, results can manifest within minutes. For more subtle effects (e.g., hormonal mood swings), consistent use over days or weeks is recommended. Keep a log of usage and emotional states to identify patterns.

Can children use essential oils for mood or focus?

Children over age two can benefit from essential oils if dilutions are reduced to 0.5–1%. Avoid peppermint or rosemary for young children due to potential respiratory sensitivity. Safe options include lavender, chamomile, and sweet orange essential oils. Always consult a pediatrician or a certified aromatherapist before using aromatherapy extensively on children.

Do I need a diffuser to experience the benefits, or is topical application sufficient?

Both methods have distinct advantages.

Diffusion offers ambient, continuous inhalation—ideal for home or office environments.
The topical application delivers constituents systemically through the skin, providing longer-lasting effects, particularly for localized issues such as tension headaches.
Choose based on convenience, target concern, and personal preference.

References

Footnotes

Koulivand, P. H., Khaleghi Ghadiri, M., & Gorji, A. (2013). Lavender and the Nervous System. Evidence-Based Complementary and Alternative Medicine, 2013, 681304.

Moss, M., Cook, J., Wesnes, K., & Duckett, P. (2003). Aromas of rosemary and lavender essential oils differentially affect cognition and mood in healthy adults. International Journal of Neuroscience, 113(1), 15–38.

Komaroff, M. (2017). The Effect of Inhalation of Aromatherapy with Lavender Oil on Anxiety in Pregnant Women: A Randomized Controlled Clinical Trial. Iranian Journal of Nursing and Midwifery Research, 22(6), 457–462.

Goel, N., Kim, H., & Lao, R. P. (2005). An olfactory stimulus modifies nighttime wind-up of rat spinal nociceptive neurons: Role of nitric oxide. Journal of Pain, 6(2), 76–83.

Chamine, I., & Oken, B. S. (2015). Increased saliva cortisol variability for a brief response to acute stress in ylang-ylang aromatherapy. Journal of Complementary and Integrative Medicine, 12(2), 135–141.

Hungund, B., Nanjageri, H., Madona, S. M., Rai, R., & Jayaramaiah, K. V. (2013). Effect of aromatherapy with essential oils of clary sage, lavender, and grapefruit on women’s stress and biochemical parameters. Indian Journal of Pharmaceutical Sciences, 75(1), 96–100.

Amsterdam, J. D., Shults, J., Soeller, I., Mao, J. J., Rockwell, K., Newberg, A. B., & Shults, J. (2016). Chamomile (Matricaria recutita) may provide antidepressant activity in anxious, depressed humans: an exploratory study. Alternatives in Complementary Therapies, 22(2), 37–44.

Moss, M., Hewitt, S., Moss, L., & Wesnes, K. (2008). Modulation of cognitive performance and mood by aromas of peppermint and ylang-ylang. International Journal of Neuroscience, 118(1), 59–77.

Raudenbush, B., & Meyer, B. (2002). Citrus limon (lemon) aroma and self-reported alertness. Human Psychopharmacology, 17(7), 341–344.

Hritcu, L., Noumedem, J. A., Cioanca, O., Hancianu, M., & Mihasan, M. (2014). Inhibitory activity of Plectranthus cylindraceus essential oil on AChE and BChE enzymes. Food Chemistry, 16(3), 465–471.

Rice, S. L., & Gibbons, S. R. (2015). Anxiolytic effects of vetiver essential oil: a randomized, double-masked, placebo-controlled study. Journal of Alternative and Complementary Medicine, 21(6), 331–338.