Research Library

People ask what science says about essential oils. This page lists published studies on some of the plants we carry, so you can read them yourself: what was tested, what the researchers reported, and the limits of each study.

Please read this first. These are summaries of other people's research. The studies did not use our products, and they do not show that any of our products treat, cure or prevent a condition. Our oils are sold as cosmetics and aromatic products. Several studies used a specific preparation (a gel, a lotion, a capsule) that is not what we sell. Never swallow essential oils. For any health concern, talk to a doctor or pharmacist.

Lavender

Lavandula angustifolia

What was studied: A 2019 systematic review and meta-analysis gathered 65 randomised trials (about 8,000 participants) on lavender and anxiety, and pooled 37 of them.
What the researchers reported: Inhaled lavender was associated with lower scores on anxiety questionnaires across the pooled trials, as was massage with lavender oil. The strongest results were for a lavender oil capsule taken by mouth, which is a licensed medicine in some countries and not something we sell.
Limits: The authors rated most trials as low quality and the inhalation studies as very different from one another, so they called the inhalation result an "indication" of an effect and asked for better trials.

Donelli D, et al. Effects of lavender on anxiety: a systematic review and meta-analysis. Phytomedicine 2019;65:153099. PubMed

Bergamot

Citrus bergamia

What was studied: 41 healthy women aged 20 to 23 rested for 15 minutes in three conditions, in random order: rest alone, rest with water vapour, and rest with water vapour plus bergamot oil from a diffuser.
What the researchers reported: With bergamot, participants scored lower for tension, anxiety and fatigue than at rest alone. Saliva cortisol was lower with bergamot and with plain vapour than at rest alone, with no clear difference between the two.
Limits: Small group of young women only, no placebo scent, and participants could tell when the oil was in the air.

Watanabe E, et al. Effects of bergamot essential oil aromatherapy on mood states, parasympathetic nervous system activity, and salivary cortisol levels in 41 healthy females. Forsch Komplementmed 2015;22(1):43–49. Publisher

Sweet orange

Citrus sinensis

What was studied: 72 patients waiting for dental treatment, with orange scent diffused in the waiting room for half of them.
What the researchers reported: Women in the scented room reported lower anxiety, a more positive mood and more calm than women without the scent.
Limits: One small study, self-reported measures, and no comparable result reported for men.

Lehrner J, et al. Ambient odor of orange in a dental office reduces anxiety and improves mood in female patients. Physiol Behav 2000;71(1–2):83–86. PubMed

Ylang-ylang

Cananga odorata

What was studied: 24 healthy volunteers inhaled ylang-ylang oil or an odourless placebo while researchers measured pulse, blood pressure, breathing and skin temperature, and asked how they felt.
What the researchers reported: Compared with placebo, blood pressure and pulse were lower and participants rated themselves more attentive and alert. The authors described the effect as "harmonising" rather than sedating.
Limits: Very small, short laboratory study in healthy people.

Hongratanaworakit T, Buchbauer G. Evaluation of the harmonizing effect of ylang-ylang oil on humans after inhalation. Planta Med 2004;70(7):632–636. PubMed

Rose

Rosa damascena, Rosa centifolia

What was studied: A review of 13 human trials (772 participants) that used rose oil by inhalation or on the skin.
What the researchers reported: The trials looked mostly at pain and at physical relaxation, with a few on mood and anxiety. The reviewers summarised the results as encouraging.
Limits: The reviewers noted that most rose research is in animals, human trials are few and small, and larger, better-designed trials are needed.

Mohebitabar S, et al. Therapeutic efficacy of rose oil: a comprehensive review of clinical evidence. Avicenna J Phytomed 2017;7(3):206–213. Open access

Peppermint

Mentha × piperita

What was studied: 41 adults with tension-type headaches treated 164 headaches in a double-blind crossover trial. A 10% peppermint oil solution in ethanol was spread on the forehead and temples and compared with a placebo solution and with 1,000 mg of acetaminophen.
What the researchers reported: Headache intensity fell more with the peppermint solution than with placebo from 15 minutes onward, and the result was not significantly different from acetaminophen.
Limits: One small trial of a specific pharmaceutical preparation. Our peppermint oil is undiluted and must never be used neat on the face or near the eyes.

Göbel H, et al. Effectiveness of Oleum menthae piperitae and paracetamol in therapy of headache of the tension type (in German). Nervenarzt 1996. PubMed

Tea tree

Melaleuca alternifolia

What was studied: 60 people with mild to moderate acne used either a 5% tea tree oil gel or a placebo gel for 45 days.
What the researchers reported: Lesion counts and severity scores improved more with the tea tree gel than with placebo; side effects were similar in both groups.
Limits: One small, short trial of a ready-made 5% gel. Acne that is painful, deep or scarring is a question for a pharmacist or dermatologist.

Enshaieh S, et al. The efficacy of 5% topical tea tree oil gel in mild to moderate acne vulgaris: a randomized, double-blind placebo-controlled study. Indian J Dermatol Venereol Leprol 2007;73(1):22–25. WHO IMSEAR

For a broad overview of laboratory and human research on tea tree oil: Carson CF, Hammer KA, Riley TV. Melaleuca alternifolia (tea tree) oil: a review of antimicrobial and other medicinal properties. Clin Microbiol Rev 2006;19(1):50–62. PubMed

Rosemary

Salvia rosmarinus (Rosmarinus officinalis)

What was studied: 100 people with androgenetic (pattern) hair loss applied either a rosemary oil lotion or 2% minoxidil to the scalp for six months.
What the researchers reported: Neither group changed at three months. At six months, hair counts had risen in both groups, with no significant difference between them. Scalp itching was more common with minoxidil.
Limits: No placebo group, the lotion's exact make-up is not fully described, and 2% is the weaker minoxidil strength. Hair loss has many causes; see a doctor or dermatologist.

Panahi Y, et al. Rosemary oil vs minoxidil 2% for the treatment of androgenetic alopecia: a randomized comparative trial. Skinmed 2015;13(1):15–21. Repository record

Thyme, rosemary, lavender and cedarwood

A blend in jojoba and grapeseed oil

What was studied: 86 people with alopecia areata (patchy hair loss) massaged either the essential oil blend in carrier oils, or the carrier oils alone, into the scalp every day for seven months, in a double-blind trial.
What the researchers reported: 19 of 43 people (44%) in the essential oil group improved, against 6 of 41 (15%) with carrier oils alone.
Limits: A single trial from 1998 that has not been widely repeated. Alopecia areata needs a doctor's diagnosis.

Hay IC, Jamieson M, Ormerod AD. Randomized trial of aromatherapy: successful treatment for alopecia areata. Arch Dermatol 1998;134(11):1349–1352. PubMed

Helichrysum

Helichrysum italicum

What was studied: A 2014 review of the plant's traditional uses and the laboratory research behind them.
What the researchers reported: The plant is promising in laboratory work, but most of its traditional uses have not been confirmed scientifically.
Limits: The reviewers called for clinical trials; few exist on the essential oil itself.

Antunes Viegas D, et al. Helichrysum italicum: from traditional use to scientific data. J Ethnopharmacol 2014;151(1):54–65. Repository record

Jojoba

Simmondsia chinensis

What was studied: A short review of jojoba's chemistry (a liquid wax rather than a true oil) and its uses in dermatology and cosmetics.
Why it's here: Jojoba is the carrier we recommend most, and this review explains why it is so stable and so close to skin's own oils.

Pazyar N, et al. Jojoba in dermatology: a succinct review. G Ital Dermatol Venereol 2013. PubMed

Oils with little research

Some of our most precious oils have long histories and almost no modern human studies. We would rather say so than borrow results from other plants.

Blue lotus (Nymphaea caerulea) and pink lotus (Nelumbo nucifera): ritual and perfumery use going back thousands of years; we have not found controlled human studies of the absolutes.
Frankincense (Boswellia): most published research looks at extracts of the resin taken by mouth, not at the essential oil used in aromatherapy.
Vetiver: valued in perfumery as a base note; human research on the oil is very limited.

How we choose what goes here

We list peer-reviewed studies in people, and reviews of them, that we have read ourselves. We describe each one as its authors did, with its limits, and we link to the source. If you know a study we should add, or think we have described one unfairly, write to aura.elixir@outlook.com.

Last reviewed: October 2026.

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