Lemon Oil for Stress and Anxiety: An Evidence Review

The search found four human trials of lemon oil with an anxiety outcome, and two reported lower anxiety while two did not. That is 222 participants in total across four very different settings, set against pooled reviews that cover dozens of trials and mostly other oils. This article goes through the trials one at a time, separates the orange and lavender dental-office work from lemon, labels the animal studies, and ends with the thresholds at which worry is a matter for a physician or licensed therapist. Nothing here is a stress or anxiety claim for this shop's lemon oil.

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The four lemon trials side by side

TrialWho and whatAnxiety result as reported
Johnson, 201931 nursing students; lemon oil inhaled through a personal nasal device around a high-stakes exam; Cognitive Test Anxiety ScaleNo statistically significant change in either group (P = .19)
Rambod et al., 2020100 patients with acute myocardial infarction; lemon inhalation for three days against a paraffin control; assessor-blindedAnxiety and heart rate differed between groups on day 4; no p-values in the abstract
Özer et al., 202246 first-year nursing students (22 lemon, 24 control); 15 minutes of smelling the oil; two test-anxiety scalesLower post-test scores than controls; authors state a 43.3% reduction without saying how it was calculated; between-group p-values not in the abstract
Sirkeci et al., 202345 first-time mothers in labor, 15 per group: lemon, ylang-ylang, controlNo significant difference in state anxiety (P = 0.750 and 0.663) or trait anxiety (P = 0.094); labor pain was lower in both oil groups (P = 0.005)

Sources: Johnson, 2019; Rambod et al., 2020; Özer et al., 2022; Sirkeci et al., 2023. The arithmetic is 31 + 100 + 46 + 45 = 222. The search was a title-keyword search of PubMed, so other lemon trials may exist, and the abstracts, which were what the search read, leave out details of blinding and analysis.

Look at what the positive ones cannot say. Özer's 43.3% is a relative reduction from a baseline, in 46 students, with the abstract not describing what the control group did during the 15 minutes. Rambod's design is stronger on blinding of the assessor, but the patients were having a heart attack, and only day 4 is named for the anxiety result. The null ones are just as small: Johnson's 31 students and Sirkeci's 15 per group could miss a modest effect. One honest reading is mixed, with low certainty either way. A second honest reading is that the setting (an exam, a heart attack, labor) changes the answer so much that four trials cannot be pooled by eye.

The dental-office studies are about orange and lavender

A common route to a "citrus calms anxiety" headline runs through Lehrner and colleagues (2005): 200 dental patients aged 18 to 77, four groups (ambient orange odor, ambient lavender odor, music, and a no-odor, no-music control), assessed while waiting for treatment. Compared with control, both orange and lavender reduced anxiety and improved mood (Lehrner et al., 2005). Lemon was not studied. Orange and lemon share a citrus label, but a different oil is a different material, and a different oil's result does not transfer.

What the pooled reviews cover

Lee and colleagues (2011) reviewed 16 randomized trials from 1990 to 2010 in people with anxiety symptoms; most reported anxiety-reducing effects, no adverse events were reported, and the authors asked for better methodological quality (Lee et al., 2011). Gong and colleagues (2020) meta-analyzed 25 articles covering 32 trials to October 2019 and reported a weighted mean difference of -5.16 on the state anxiety inventory (95% CI -5.78 to -4.55) and -2.85 on trait anxiety (95% CI -3.95 to -1.75), with the authors saying that the proper essential-oil dosage needs further research (Gong et al., 2020). Neither abstract names the oils, participant totals or a formal bias assessment, so neither can be read as a statement about lemon. In a pregnancy-focused meta-analysis, the oils named for the anxiety result were Citrus aurantium, rose, mint and orange blossom, and lemon was not among them (Mascarenhas et al., 2025).

The reasonable reading, labelled as reasoning: aroma as a category is associated with lower self-rated anxiety in many small trials, and the oil-specific evidence for lemon is thin and mixed. A pooled number across mixed oils is not a measurement of one bottle.

Physiology and animals are separate questions

Kiecolt-Glaser and colleagues (2008) gave 56 healthy adults lavender, lemon and water on three visits and found that lemon raised self-rated positive mood while salivary cortisol, IL-6, IL-10, heart rate and blood pressure showed no reliable change; norepinephrine stayed higher after the stressor with lemon (abstract). NCCIH, on a page updated in January 2020, summarizes it this way: lemon "had a positive effect on mood," but neither scent affected stress indicators (NCCIH, 2020). The mood results are on the mood and energy page.

In mice, Komiya, Takeuchi and Harada (2006) reported that lemon oil vapor had the strongest anti-stress effect of lavender, rose and lemon across three behavioral tests, with effects blocked by a benzodiazepine-receptor antagonist and a dopamine agonist (Komiya et al., 2006). In rats exposed to lemon oil odor for two weeks, Ceccarelli and colleagues (2004) reported less open-arm time on the elevated plus-maze, higher pain thresholds and lower corticosterone (Ceccarelli et al., 2004). Those are rodent studies with different exposures, and nothing in them concerns people smelling a room scent or using lemon oil on skin. The same goes for cell and lemon-juice studies, which are further removed still.

When worry needs a professional

NIMH describes anxiety disorders as anxiety that "does not go away, is felt in many situations, and can get worse over time," and says it can interfere with work, school and relationships. For generalized anxiety disorder, NIMH describes difficulty controlling worry on most days for at least 6 months, with at least three symptoms from a list that includes restlessness, fatigue, trouble concentrating, irritability, muscle tension and sleep problems, and says it is time to seek professional help when anxiety begins to cause problems in daily life (NIMH, GAD). The NHS gives no numeric cutoff: see a GP if you think you might have it or treatment is not helping, and adults in England can self-refer to NHS talking therapies; its page does not mention aromatherapy (NHS, GAD). NIMH's main page gives 988 (call or text) for anyone struggling or having thoughts of suicide, and 911 in a life-threatening situation (NIMH). The person to ask is a physician or a licensed therapist.

Where this shop stands

The FDA regulates aromatherapy products by intended use, judged from labeling, websites and advertising, and lists claims such as treating depression or anxiety among drug claims (FDA, aromatherapy). We sell one lemon oil, neat, as a scent material. We make no medical claim for it, we sell no remedy, and our copy says do not take it internally and keep it from children and pets. A bright citrus smell in a room is a pleasure some people enjoy; it is not a treatment for worry.

For a plain reading of every claim in circulation see benefits, honestly; for what the smell actually is, the smell guide; and for skin, children and sunlight, the safety article.

Organic Lemon Essential Oil bottle

Organic Lemon Essential Oil

Organic Lemon Essential Oil from our own shop, in sizes from 0.5 oz to bulk.

From $15.99

Shop Now →

Sources & Further Reading