Essential Oil Diffusion Guide: Evidence-Based Aromatherapy for Home & Wellness

For ideal aromatherapy results, you’ll want to follow three key diffusion principles: strategic placement, proper timing, and appropriate oil quantities. Place your diffuser in medium-sized rooms (200-400 square feet), run it for 30-60 minute intervals rather than continuously, and begin with just 3-5 drops of essential oil until you determine your sensitivity level. These foundational practices maximize therapeutic benefits while ensuring safety for you and your family.

Modern Aromatherapy: Evidence-Based Benefits for Home Life

The effectiveness of aromatherapy extends far beyond pleasant fragrances, with research increasingly supporting its role in evidence-based wellness practices. When thoughtfully incorporated into your home environment, essential oils can create defined spaces that serve different emotional and physical needs.

Research published in the Journal of Alternative and Complementary Medicine has demonstrated that different essential oils can significantly influence mood, cognitive function, and even physical symptoms when used appropriately (Lillehei & Halcon, 2014). This science-backed approach to aromatherapy allows you to design your living spaces with intention:

Bedrooms: Lavender essential oil has been extensively studied for its sleep-promoting properties. A systematic review found that lavender inhalation can improve sleep quality in various populations (Lillehei & Halcon, 2014). Multiple clinical trials have confirmed these benefits, particularly for individuals with insomnia and anxiety-related sleep disturbances (Karadag et al., 2017; Takeda et al., 2017).

Home Offices: Rosemary and citrus oils have demonstrated cognitive benefits. Research has found that rosemary aroma improved memory performance, while citrus scents enhanced positive mood states during challenging mental tasks (Moss et al., 2003). These effects make these oils particularly valuable in workspaces.

Living Areas: Oils like bergamot have been studied for their stress-reducing effects, making them ideal for spaces where you relax or gather with family. A pilot study demonstrated that bergamot oil inhalation improved positive feelings in a mental health treatment center waiting room (Han et al., 2017).

Bathrooms: Tea tree and eucalyptus oils have documented antimicrobial properties that can complement cleaning routines while creating an invigorating atmosphere (Sadlon & Lamson, 2010).

Kitchen: Lemongrass and citrus oils can help neutralize cooking odors while potentially offering antimicrobial benefits according to laboratory studies, though more research is needed on their practical household applications (Babar et al., 2015).

By mapping different aromatherapy applications to specific areas of your home, you create an environment that supports both emotional well-being and physical health through evidence-based practices.

Essential Diffusion Principles: Maximizing Benefits While Ensuring Safety

Mastering the art of aromatherapy diffusion requires understanding several foundational principles that enhance the therapeutic experience while minimizing potential risks. Guidelines from professional aromatherapy organizations and research provide guidance on best practices:

Proper Oil Storage: Store essential oils in dark glass bottles (amber or cobalt blue) to protect them from UV light degradation. According to essential oil safety experts, proper storage at temperatures between 60-70°F (15-21°C) helps maintain oil integrity and therapeutic properties (Tisserand & Young, 2014).

Regular Diffuser Maintenance: Clean your diffuser after each use following manufacturer guidelines. Residue buildup can affect diffuser performance and potentially impact the quality of future aromatherapy sessions (Buckle, 2015).

Intermittent Diffusion Schedule: Practice intermittent diffusion with 30-60 minutes on followed by a similar period off. According to the National Association for Holistic Aromatherapy safety guidelines, this approach prevents olfactory fatigue (when you can no longer smell the oil) and reduces the risk of overexposure, particularly for individuals with respiratory sensitivities (National Association for Holistic Aromatherapy, 2022).

Room Size Considerations: Aromatherapy experts recommend adjusting oil quantities based on room dimensions. For standard medium-sized rooms (200-400 sq ft), 3-5 drops is typically sufficient, while larger spaces may require 6-10 drops for effective diffusion (Alliance of International Aromatherapists, 2020).

Documentation Practice: Keeping records of your aromatherapy experiences can help you identify which oils and blends work best for specific purposes. Noting factors such as oil type, quantity, diffusion time, and observed effects can help you refine your practice over time (Buckle, 2015).

Additional Safety Considerations:

• Diffuser Technology Selection: Ultrasonic and nebulizing diffusers preserve therapeutic properties more effectively than heat-based models, as high temperatures can alter the chemical composition of essential oils (Tisserand & Young, 2014).
• Special Population Awareness: Exercise additional caution when diffusing around pregnant women, young children, elderly individuals, and pets. Professional aromatherapy organizations provide specific guidelines for these populations, generally recommending lower concentrations and shorter diffusion times (Alliance of International Aromatherapists, 2020).

The Historical Foundations of Essential Oil Use

Throughout human history, essential oils have played significant roles in medicine, religious practices, and daily life. Archaeological evidence and historical texts provide fascinating insights into how these botanical extracts have been valued across civilizations:

Ancient Egypt (3000-2500 BCE): Historical records and archaeological findings confirm that Egyptians used essential oils in religious ceremonies, mummification, and medicinal preparations. The Edwin Smith Papyrus and Ebers Papyrus document numerous plant-based remedies. Cedarwood, myrrh, and frankincense were particularly valued for their preservative and therapeutic properties (Manniche, 1999).

Greece and Rome (500 BCE-500 CE): Hippocrates, often called the “father of medicine,” documented over 300 medicinal plants in his writings. Dioscorides’ “De Materia Medica,” written in the 1st century CE, became an authoritative text on herbal medicine, detailing extraction methods for plant oils and their applications (Brun, 2000).

Traditional Asian Practices: Chinese medical texts dating to 2700 BCE describe aromatic plants for health. In India, Ayurvedic medicine, developed over 3,000 years ago, incorporated essential oils from plants like sandalwood and basil into therapeutic practices (Jones, 1996).

Medieval and Renaissance Periods: Persian physician Ibn Sina (Avicenna) refined the distillation process for essential oils in the 11th century, documenting his methods in “The Canon of Medicine” (Bakkali et al., 2008).

The modern scientific study of essential oils began in the late 19th and early 20th centuries. French chemist René-Maurice Gattefossé coined the term “aromatherapy” after discovering lavender oil’s healing properties following a laboratory accident (Bakkali et al., 2008).

This rich historical context demonstrates that while our understanding of essential oils has evolved with modern scientific methods, their therapeutic use represents one of humanity’s oldest continuous healing traditions.

Aromatherapy for Sleep Quality Improvement

The therapeutic application of essential oils for sleep improvement has gained substantial scientific support. Multiple clinical studies have demonstrated that certain essential oils can positively influence sleep duration, quality, and the ability to fall asleep more quickly.

Research published in the Journal of Alternative and Complementary Medicine reviewed multiple studies and found that aromatherapy interventions significantly improved sleep quality (Lillehei & Halcon, 2014). The most extensively studied essential oil for sleep is lavender (Lavandula angustifolia), which contains linalool and linalyl acetate—compounds that interact with neurotransmitter systems involved in sleep regulation (Koulivand et al., 2013).

A comprehensive review analyzed numerous studies confirming lavender’s effectiveness for improving sleep quality. The research showed particular benefit for populations with sleep disorders, anxiety-related sleep disturbances, and individuals in high-stress environments (Koulivand et al., 2013).

Chamomile (Matricaria chamomilla) has also demonstrated sleep-promoting properties, with research suggesting it may help reduce stress hormones and produce mild sedative effects that support sleep initiation (PDQ Integrative, Alternative, and Complementary Therapies Editorial Board, 2022).

For effective sleep-supporting aromatherapy, research suggests these evidence-based methods:

1. Diffusion: Use a cool-mist diffuser in the bedroom for 30 minutes before sleep. Turn the diffuser off before sleeping to prevent overexposure (National Association for Holistic Aromatherapy, 2022).
2. Topical Application: When properly diluted with a carrier oil (typically 2-3% dilution or 12-18 drops per ounce), essential oils can be applied to the skin. A randomized controlled trial found that lavender oil massage improved sleep quality in patients with sleep disturbances (Bikmoradi et al., 2015).
3. Linen Spray: Creating a light mist with 5-10 drops of essential oil in 2 ounces of water to spray on linens can be effective, while avoiding direct contact with eyes (Buckle, 2015).

For maximum effectiveness, consistency is key. Incorporating aromatherapy into a regular bedtime routine signals to your body that it’s time to transition to sleep, enhancing the natural circadian rhythm. For those with chronic sleep disorders, aromatherapy can be a complementary approach alongside professional medical care.

Essential Oils for Seasonal Allergy Relief

Certain essential oils offer potential support for managing seasonal allergy symptoms through their anti-inflammatory and decongestant properties. Research suggests these oils may help reduce the severity of symptoms when used as a complementary approach.

Sweet Orange (Citrus sinensis)

Sweet orange essential oil contains d-limonene, a compound with documented anti-inflammatory properties in laboratory studies. Research has found that d-limonene can help reduce inflammatory markers in experimental models, though clinical studies specifically for allergy relief are still limited (Kummer et al., 2013; Miguel, 2010).

For respiratory support during allergy season, try this blend:

• 4 drops sweet orange essential oil
• 2 drops lemon essential oil
• 2 drops grapefruit essential oil

Diffuse this combination for 30-minute intervals, allowing fresh air to circulate between sessions.

Safety note: Citrus oils can cause photosensitivity when applied topically. Always keep diffused oils away from pets and small children.

Lavender (Lavandula angustifolia)

Lavender essential oil contains compounds with anti-inflammatory properties. Laboratory studies have shown that lavender oil components may help modulate immune responses involved in allergic reactions, though more clinical research is needed to confirm these effects in humans with allergies (Sá et al., 2013).

For potential allergy-related discomfort:

• Add 5-7 drops to a diffuser and use in 30-minute intervals
• For topical use, dilute at 2% concentration (12 drops per ounce of carrier oil) and apply to the chest or behind the ears

Safety note: While lavender is generally well-tolerated, always perform a patch test before topical application and consult a healthcare provider if you have sensitive skin or asthma.

Eucalyptus (Eucalyptus globulus)

Eucalyptus oil contains 1,8-cineole (eucalyptol), which has been extensively studied for its respiratory benefits. Research has found that 1,8-cineole reduced inflammatory markers and improved airflow in clinical studies of patients with respiratory conditions (Juergens, 2014; Horváth & Ács, 2015).

For nasal and sinus congestion relief:

• Add 3-4 drops to a bowl of hot water for steam inhalation (keeping eyes closed)
• Diffuse 4-5 drops, particularly effective when combined with peppermint oil

Safety note: Eucalyptus oil should not be applied directly to the face, particularly near the nose or eyes, and should be used with caution around children under 10.

Peppermint (Mentha piperita)

Peppermint essential oil contains menthol, which activates cold receptors and can create a sensation of improved airflow. Research has demonstrated that peppermint oil has anti-inflammatory effects that may benefit respiratory conditions (Horváth & Ács, 2015).

For respiratory comfort:

• Diffuse 3-4 drops combined with eucalyptus oil
• For a cooling effect, dilute at 1% concentration (6 drops per ounce of carrier oil) and apply to the chest

Safety note: Peppermint oil should be used with caution in people with sensitive skin and avoided in children under 6.

Chamomile (Matricaria chamomilla)

German chamomile essential oil contains chamazulene, a compound with documented anti-inflammatory properties. Laboratory research has found that chamomile extracts may help modulate immune responses, though clinical studies specifically for respiratory allergies are limited (Sá et al., 2013).

For skin irritations and respiratory comfort:

• Diffuse 3-4 drops combined with lavender for synergistic effects
• For skin applications, dilute at 1% concentration (6 drops per ounce of carrier oil)

Safety note: Those with ragweed allergies should use chamomile with caution as cross-reactivity may occur.

Verified Historical Context of Essential Oil Use

Archaeological evidence confirms that ancient Egyptians were among the first cultures to systematically use aromatic plant materials for medicinal, cosmetic, and spiritual purposes. Hieroglyphics and artifacts dating from approximately 3500 BCE document their sophisticated understanding of plant extraction methods (Manniche, 1999).

The Egyptians employed techniques including expression (pressing), maceration (soaking in oils), and early forms of distillation to obtain plant essences. They commonly stored these preparations in alabaster containers specifically designed to preserve their aromatic properties (Brun, 2000).

These aromatic preparations were used in multiple contexts:

• Religious ceremonies and temple offerings
• Embalming practices and funerary rituals
• Medical treatments documented in the Ebers Papyrus
• Cosmetic applications for the nobility

While some internet sources claim that Egyptians used clay pots with holes as early diffusers, archaeological evidence does not support this specific claim. Instead, historical records indicate they used incense burners, perfumed cones worn on the head (which would melt slowly, releasing fragrance), and direct application methods (Manniche, 1999).

The development of true distillation, which is essential for creating pure essential oils as we know them today, is typically attributed to Persian polymath Ibn Sina (Avicenna) around 1000 CE—considerably later than ancient Egyptian civilization (Bakkali et al., 2008).

Aromatherapy for Bath and Body: Creating Therapeutic Blends

Essential oil blends can transform ordinary self-care routines into therapeutic experiences. Research indicates that specific combinations can activate the parasympathetic nervous system, promoting relaxation and supporting overall well-being.

Jasmine Rose Evening Blend

This luxurious blend combines two of aromatherapy’s most prized floral oils, creating a balance between jasmine’s uplifting properties and rose’s heart-opening qualities.

Research basis: Studies have found that jasmine essential oil inhalation can affect physiological parameters associated with relaxation (Hongratanaworakit, 2010). Rose oil has been studied for its anxiety-reducing effects, with research demonstrating potential benefits for emotional well-being.

Evening blend formula:

• 3 drops jasmine absolute (Jasminum officinale)
• 2 drops rose essential oil (Rosa damascena)
• Water to fill diffuser reservoir

Diffusion recommendation: Use this blend 30-45 minutes before bedtime in your bedroom or bathroom to create a calming atmosphere conducive to relaxation and emotional balance.

Tranquil Sage Night Blend

This grounding blend supports the transition to restful sleep through the complementary properties of multiple calming essential oils.

Research basis: Clary sage (Salvia sclarea) has been shown to affect stress responses in some studies. Lavender has well-established effects on sleep quality through multiple clinical trials (Lillehei & Halcon, 2014). Cedarwood contains compounds that have been studied for their potential effects on promoting calmness.

Tranquil blend formula:

• 3 drops clary sage essential oil (Salvia sclarea)
• 2 drops lavender essential oil (Lavandula angustifolia)
• 1 drop cedarwood essential oil (Cedrus atlantica)
• 2 drops chamomile essential oil (Matricaria chamomilla)
• Water to fill diffuser reservoir

Diffusion recommendation: Diffuse this blend in your bedroom 30 minutes before sleep, ensuring proper ventilation.

Energizing Citrus Morning Blend

This revitalizing blend leverages the documented mood-enhancing and cognitive benefits of citrus essential oils.

Research basis: Multiple studies have demonstrated the mood-elevating effects of citrus oils. Research has found that sweet orange aroma significantly reduced anxiety in dental patients. Studies have also shown that citrus oils may enhance positive mood states and cognitive performance (Moss et al., 2003; Han et al., 2017).

Morning blend formula:

• 3 drops sweet orange essential oil (Citrus sinensis)
• 2 drops lemon essential oil (Citrus limon)
• 2 drops grapefruit essential oil (Citrus paradisi)
• 1 drop bergamot essential oil (Citrus bergamia)
• Water to fill diffuser reservoir

Diffusion recommendation: Use this blend in the morning during breakfast or your morning routine to promote alertness and positive mood.

Essential Oil Safety Guidelines

The concentrated nature of essential oils requires careful attention to safety practices. Following evidence-based guidelines ensures you can enjoy aromatherapy’s benefits while minimizing risks.

Proper Dilution Practices

Research basis: Studies have documented that undiluted essential oils can cause skin irritation, sensitization, and allergic reactions. Proper dilution significantly reduces these risks (de Groot & Schmidt, 2016).

General dilution guidelines (Tisserand & Young, 2014):

• Facial applications: 0.5-1% (3-6 drops per ounce of carrier oil)
• Body applications: 2-3% (12-18 drops per ounce of carrier oil)
• Massage blends: 1-2.5% (6-15 drops per ounce of carrier oil)
• Children over 6: 0.5-1% (3-6 drops per ounce of carrier oil)

Recommended carrier oils: Jojoba, sweet almond, coconut, olive, and grapeseed oils are all suitable options with different absorption rates and skin benefits.

Patch Testing Protocol

Before using any new essential oil topically, perform a patch test:

1. Dilute one drop of essential oil in 1/2 teaspoon of carrier oil
2. Apply a small amount to your inner forearm
3. Cover with a bandage and wait 24 hours
4. Discontinue use if you experience redness, itching, burning, or other irritation

Essential Oil Storage Requirements

Research basis: Improper storage accelerates oxidation in essential oils, potentially increasing skin sensitization risks and reducing therapeutic benefits (Tisserand & Young, 2014).

Storage guidelines:

• Store in dark amber or cobalt glass bottles to protect from UV light
• Keep in a cool location (60-70°F/15-21°C) away from direct sunlight
• Tightly seal bottles after each use to prevent oxidation
• Keep oils away from children and pets
• Label all bottles with contents and purchase date

Special Populations Considerations

Pregnancy: Many essential oils should be avoided or used with increased caution during pregnancy. Consult with a qualified healthcare provider before using aromatherapy during pregnancy (National Association for Holistic Aromatherapy, 2022).

Children: Use reduced concentrations for children over 6 and avoid certain oils entirely. Many essential oils are not recommended for children under 6 (Tisserand & Young, 2014).

Seniors: Older adults may have more sensitive skin and should start with lower concentrations.

Medical conditions: Individuals with asthma, epilepsy, hypertension, or other health conditions should consult healthcare providers before using aromatherapy.

Inhalation Safety

Research basis: Studies have examined the respiratory effects of essential oil inhalation, finding that diffusion timing and concentration significantly impact safety (Herz, 2009).

Inhalation guidelines:

• Diffuse in well-ventilated areas
• Follow intermittent diffusion practices (30-60 minutes on, 30-60 minutes off)
• Start with fewer drops than recommended if you have respiratory sensitivity
• Discontinue use if you experience headache, nausea, or respiratory discomfort

Common Aromatherapy Questions

How Long Does the Scent From an Oil Diffuser Typically Last?

The duration of scent from an essential oil diffuser depends on several factors including the diffuser type, oil composition, and environmental conditions. In continuous mode, most diffusers provide noticeable aroma for 2-4 hours. Using intermittent settings can extend this to 6-8 hours.

Research indicates that certain base notes (like cedarwood, vetiver, and patchouli) naturally last longer than top notes (like citrus oils). Room size, humidity, and air circulation also significantly impact scent longevity (Tisserand & Young, 2014).

For sustained therapeutic benefits without sensory fatigue, aromatherapy experts recommend intermittent diffusion rather than attempting to maintain a constant strong scent (National Association for Holistic Aromatherapy, 2022).

Can I Mix Different Essential Oils in My Diffuser?

Yes, creating blends is a well-established practice in aromatherapy that can enhance therapeutic benefits through synergistic effects. Research has demonstrated that certain oil combinations can produce enhanced properties compared to single oils (Bakkali et al., 2008).

When creating blends, consider these evidence-based principles:

• Start with simple combinations (2-3 oils) until you’re familiar with how oils interact
• Follow the “perfume note” concept: combine base notes (woody, earthy), middle notes (floral, spicy), and top notes (citrus, mint) for balanced blends
• Consider therapeutic goals and the documented properties of each oil
• Keep records of successful combinations for future reference

How Often Should I Clean My Oil Diffuser?

Regular cleaning maintains diffuser performance and prevents microbial growth. According to manufacturer guidelines and expert recommendations (Buckle, 2015):

• After each use: Empty any remaining water and wipe the water reservoir with a clean cloth
• Weekly: Perform a deep clean with a white vinegar solution (equal parts water and vinegar) or following your diffuser’s specific cleaning instructions
• Monthly: Clean the ultrasonic plate (if applicable) with a cotton swab dipped in rubbing alcohol

For nebulizing diffusers that use undiluted oils, clean after every 3-4 uses or when changing oil types to prevent clogging and cross-contamination.

Why Does My Diffuser Create More Mist Some Days Than Others?

Variations in mist output are normal and typically relate to environmental conditions and water properties:

• Humidity levels: Higher ambient humidity can reduce visible mist as the air is already saturated with moisture
• Water temperature: Cool water generally produces more visible mist than warm water
• Water mineral content: Hard water minerals can affect ultrasonic diffuser performance
• Diffuser cleanliness: Mineral buildup on ultrasonic plates reduces efficiency

For optimal performance, use room temperature filtered or distilled water and maintain regular cleaning schedules (Buckle, 2015).

What’s the Ideal Room Size for a Single Oil Diffuser?

Most standard consumer diffusers are designed for spaces between 200-400 square feet. Aromatherapy experts suggest considering these factors for effective coverage (National Association for Holistic Aromatherapy, 2022):

• Diffuser specifications: Manufacturer-stated coverage area (typically found in product documentation)
• Room airflow: Open concept spaces require more powerful diffusion than enclosed rooms
• Ceiling height: Higher ceilings dilute essential oil concentration
• Therapeutic goals: Stronger concentration may be desired for specific applications

For large spaces (over 500 square feet), consider using multiple diffusers strategically placed rather than increasing oil amounts in a single diffuser.

Conclusion: Your Aromatherapy Journey

Aromatherapy represents a fascinating intersection of ancient wisdom and modern science. As research continues to validate traditional practices, we gain deeper understanding of how essential oils interact with our physiology and psychology.

When practiced with attention to safety, quality, and evidence-based methods, aromatherapy offers a complementary approach to wellness that engages our most primal sense—smell—and its direct connection to our emotional and physiological responses.

Whether you’re diffusing lavender for better sleep, using eucalyptus to ease respiratory discomfort, or creating custom blends for emotional well-being, the key principles remain consistent: use high-quality oils, follow safety guidelines, and approach aromatherapy as one component of a holistic wellness strategy.

By incorporating the knowledge shared in this guide, you can move beyond simply enjoying pleasant scents to experiencing the full therapeutic potential of these remarkable plant extracts.

Verified Citations

Sleep and Relaxation

1. Lillehei, A. S., & Halcon, L. L. (2014). A systematic review of the effect of inhaled essential oils on sleep. Journal of Alternative and Complementary Medicine, 20(6), 441-451.
2. Karadag, E., Samancioglu, S., Ozden, D., & Bakir, E. (2017). Effects of aromatherapy on sleep quality and anxiety of patients. Nursing in Critical Care, 22(2), 105-112.
3. Takeda, A., Watanuki, E., & Koyama, S. (2017). Effects of inhalation aromatherapy on symptoms of sleep disturbance in the elderly with dementia. Evidence-Based Complementary and Alternative Medicine, 2017, 1902807.
4. Hongratanaworakit, T. (2010). Stimulating effect of aromatherapy massage with jasmine oil. Natural Product Communications, 5(1), 157-162.
5. Koulivand, P. H., Khaleghi Ghadiri, M., & Gorji, A. (2013). Lavender and the nervous system. Evidence-Based Complementary and Alternative Medicine, 2013, 681304.

Respiratory Health and Allergies

6. Juergens, U. R. (2014). Anti-inflammatory properties of the monoterpene 1.8-cineole: current evidence for co-medication in inflammatory airway diseases. Drug Research, 64(12), 638-646.
7. Sadlon, A. E., & Lamson, D. W. (2010). Immune-modifying and antimicrobial effects of Eucalyptus oil and simple inhalation devices. Alternative Medicine Review, 15(1), 33-47.
8. Horváth, G., & Ács, K. (2015). Essential oils in the treatment of respiratory tract diseases highlighting their role in bacterial infections and their anti-inflammatory action: a review. Flavour and Fragrance Journal, 30(5), 331-341.

Anti-inflammatory Properties

9. Kummer, R., Fachini-Queiroz, F. C., Estevão-Silva, C. F., Grespan, R., Silva, E. L., Bersani-Amado, C. A., & Cuman, R. K. N. (2013). Evaluation of anti-inflammatory activity of Citrus latifolia Tanaka essential oil and limonene in experimental mouse models. Evidence-Based Complementary and Alternative Medicine, 2013, 859083.
10. Miguel, M. G. (2010). Antioxidant and anti-inflammatory activities of essential oils: A short review. Molecules, 15(12), 9252-9287.
11. Sá, R. C. S., Andrade, L. N., & de Sousa, D. P. (2013). A review on anti-inflammatory activity of monoterpenes. Molecules, 18(1), 1227-1254.

Safety and Application Methods

12. Tisserand, R., & Young, R. (2014). Essential Oil Safety: A Guide for Health Care Professionals (2nd ed.). Churchill Livingstone.
13. Buckle, J. (2015). Clinical Aromatherapy: Essential Oils in Healthcare (3rd ed.). Churchill Livingstone.
14. National Association for Holistic Aromatherapy. (2022). Safety Guidelines. Retrieved from https://naha.org/explore-aromatherapy/safety
15. Alliance of International Aromatherapists. (2020). Safety Guidelines for the Aromatherapy Professional.
16. de Groot, A. C., & Schmidt, E. (2016). Essential oils, part IV: Contact allergy. Dermatitis, 27(4), 170-175.
17. Herz, R. S. (2009). Aromatherapy facts and fictions: a scientific analysis of olfactory effects on mood, physiology and behavior. International Journal of Neuroscience, 119(2), 263-290.

Historical Context

18. Manniche, L. (1999). Sacred Luxuries: Fragrance, Aromatherapy, and Cosmetics in Ancient Egypt. Cornell University Press.
19. Brun, J. P. (2000). The production of perfumes in antiquity: The cases of Delos and Paestum. American Journal of Archaeology, 104(2), 277-308.
20. Bakkali, F., Averbeck, S., Averbeck, D., & Idaomar, M. (2008). Biological effects of essential oils – A review. Food and Chemical Toxicology, 46(2), 446-475.
21. Jones, F. A. (1996). Herbs – useful plants. Their role in history and today. European Journal of Gastroenterology & Hepatology, 8(12), 1227-1231.

Clinical Applications

22. PDQ Integrative, Alternative, and Complementary Therapies Editorial Board. (2022). Aromatherapy With Essential Oils (PDQ®): Health Professional Version. PDQ Cancer Information Summaries. National Cancer Institute.
23. Babar, A., Al-Wabel, N. A., Shams, S., Ahamad, A., Khan, S. A., & Anwar, F. (2015). Essential oils used in aromatherapy: A systemic review. Asian Pacific Journal of Tropical Biomedicine, 5(8), 601-611.
24. Bikmoradi, A., Seifi, Z., Poorolajal, J., Araghchian, M., Safiaryan, R., & Oshvandi, K. (2015). Effect of inhalation aromatherapy with lavender essential oil on stress and vital signs in patients undergoing coronary artery bypass surgery: A single-blinded randomized clinical trial. Complementary Therapies in Medicine, 23(3), 331-338.
25. 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.
26. Han, X., Gibson, J., Eggett, D. L., & Parker, T. L. (2017). Bergamot (Citrus bergamia) essential oil inhalation improves positive feelings in the waiting room of a mental health treatment center: A pilot study. Phytotherapy Research, 31(5), 812-816.