Anxiety:

A review of three randomised, double-blind clinical trials investigated the efficacy and tolerability of a proprietary oral lavender oil capsule preparation (‘Silexan’) in the treatment of anxiety disorders. Silexan (80 mg/day) (n = 280) was found to be superior to placebo (n = 192), while incidence of adverse events in patients treated with the preparation was comparable to placebo (Kasper et al. 2010). In another study, silexan was compared against lorazepam in the treatment of generalised anxiety disorder. The results showed that silexan ameliorated symptoms of generalised anxiety comparable to lorazepam. No sedative effects were associated with silexan. The authors concluded that silexan appears to be a well-tolerated alternative to benzodiazepines for amelioration of generalised anxiety (Woelk and Schläfke 2011). A phase II clinical trial investigated silexan (administered 1 × 80 mg/day for 6 weeks) in 50 patients with neurasthenia, and post-traumatic stress disorder. Patients showed statistically significant and clinically meaningful improvements of symptoms like restlessness, sleep-disturbances and sub-threshold anxiety (Uehleke et al. 2013).

In a systematic review of randomised clinical trials investigating anxiolytic activity of lavender oil, 15 trials met the inclusion criteria, of which 7 appeared to favour lavender over control for at least one clinical outcome. The authors concluded that methodological issues limit the extent to which conclusions can be drawn, but that the evidence suggests that lavender oil does have some therapeutic effects (Perry et al. 2012).

Sleep:

A systematic review assessed available evidence on lavender aroma inhalation as a possible self-care intervention to improve sleep architecture (initiation, maintenance and quality). Initial results from eight eligible studies (including four randomised controlled trials) were promising, although they had small sample sizes and methodological limitations (Fismer and Pilkington 2012).

Coronary circulation:

The effect of lavender aromatherapy on coronary circulation in 30 young healthy men in a single-blind (operator) study was assessed by measuring coronary flow velocity reserve (CFVR), using non-invasive transthoracic Doppler echocardiography. Lavender aromatherapy significantly decreased serum cortisol and improved CFVR, indicating its relaxation effects and beneficial effects on coronary circulation (Shiina et al. 2008).

Pain:

A randomised controlled trial in 92 patients undergoing haemodialysis with arteriovenous fistulas found that inhalation of lavender significantly reduced pain compared to placebo following needle insertion into a fistula (Bagheri-Nesami et al. 2014). In another randomised controlled trial in 48 children aged 6–12 years, inhalation of essential lavender oil caused a statistically significant reduction in daily use of acetaminophen post-operatively following tonsillectomy (Soltani et al. 2013).