A Systematic Review and Meta-Analysis of the Effects of Lavender Aromatherapy on Sleep Quality and Restless Leg Syndrome

Quality sleep is crucial for overall well-being. Although lavender aromatherapy, delivered via inhalation or massage, is well-known for its relaxing and sedative effects, can it be endorsed as an alternative treatment option? This systematic review assessed the effects of lavender aromatherapy as a potential safe and low-cost alternative treatment to enhance sleep quality and reduce RLS severity. Methods Sleep quality and RLS severity reduction were evaluated. RCTs using lavender aromatherapy via inhalation or massage were included. EMBASE, APA PsycInfo, PubMed, CINAHL, Scopus, and CENTRAL were searched, identifying 1556 references. Meta-analyses were grouped according to outcome measures, risk of bias was assessed using RoB2, and the strength of the evidence was evaluated using GRADEpro. (PROSPERO CRD42023408799). Results After deduplication and screening, 35 RCTs were included , comparing lavender aromatherapy (inhalation or massage) with placebo or standard care. In pairwise meta-analysis, lavender inhalation was significantly more effective than placebo (MD: -4.72; 95%CI[-6.96, -2.48]; I 2 :90%) and standard care (MD: -2.62; 95%CI[-3.93, -1.33]; I 2 :78%) and lavender massage was more effective than placebo (MD: -2.95; 95%CI[-5.61, -0.30]; I 2 : 74%) and standard care (MD: -3.85; 95%CI[-6.55, -1.14]; I 2 : 94%) for improving sleep quality, assessed using the PSQI, but not significant effect was found when assessed with SMHSQ (MD: -1.15; 95%CI[-4.69, 2.38]; I 2 : 48%) and OSA-MA (MD: 1.31; 95%CI[-10.25, 12.87]; I 2 : 90%). Lavender massage was significantly more effective than placebo (MD: -13.41; 95%CI[-16.91, -9.92]; I 2 : 68%) and standard care (MD: -9.63; 95%CI[-15.58, -3.68]; I2: 93%) in reducing RLS severity. RoB2 assessment identified some methodological concerns and risk of bias. The overall strength of evidence assessed by GRADE was considered low. Conclusions Although the overall certainty of evidence is low, and substantial heterogeneity and risk of bias limit the strength of the findings, lavender aromatherapy may be associated with small-to-moderate improvements in sleep quality and RLS severity. While it could represent a safe and low-cost non-pharmacological intervention, the current evidence is insufficient to draw firm conclusions regarding its effectiveness. Further high-quality, adequately powered, and less heterogeneous trials are required to strengthen the evidence base and clarify the magnitude of the effect.