We present a narrative review of clinical trials investigating the anxiolytic and antidepressant effects of silexan, an active substance derived from lavender oil and summarize nonclinical findings from pharmacological studies supporting its therapeutic use. Six studies investigated the efficacy of the lavender oil in patients with subthreshold and generalized anxiety disorders as well as in mixed anxiety and depressive disorder (MADD). Furthermore, we present data indicating that silexan may influence sleep quality as well as anxiety or depressive disorders in individuals with post-COVID-19. Silexan taken orally at a daily dose of 80mg for 10 weeks was significantly superior to placebo in reducing psychic and somatic symptoms of anxiety and was as effective as 0.5mg/d lorazepam and 20mg/d paroxetine. In patients with mild or moderate major depression, silexan was superior to placebo and comparably effective to 50mg/d sertraline. Significant antidepressant effects were also observed in MADD and depression co-morbid with anxiety. The herbal product had a beneficial effect on activities of daily living and health-related quality of life. Adverse events associated with silexan in clinical trials were limited to eructation and mild, transient gastrointestinal complaints. The herbal product was not associated with drug interactions, sedation, sleep disturbance, dependence and abuse potential, sexual dysfunction, weight gain or withdrawal symptoms. Silexan was therefore safe and effective in subthreshold and syndromal anxiety disorders and in major depression.