Silexan Lavender Oil: The Oral Anxiolytic Hiding in Plain Sight

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Silexan is a standardised oral lavender oil preparation (sold as Lasea) licensed as a medicine for generalised anxiety disorder and subthreshold anxiety in several European countries. Among herbal anxiolytics, it is unusual for having been tested head-to-head against an SSRI and a benzodiazepine in registration-grade randomised trials — and for having held up in both comparisons.

Head-to-Head Trial Data

The Kasper 2014 trial in the International Journal of Neuropsychopharmacology (PMID 24456909; DOI 10.1017/S1461145714000017) randomised 539 adults with generalised anxiety disorder (DSM-5, baseline HAM-A ≥ 18) to Silexan 160 mg/day, Silexan 80 mg/day, paroxetine 20 mg/day, or placebo for 10 weeks. Both Silexan doses produced significantly larger HAM-A reductions than placebo (p < 0.01); Silexan 160 mg/day reduced HAM-A by 14.1 ± 9.3 points versus 9.5 ± 9.0 with placebo and 11.3 ± 8.0 with paroxetine. Adverse-event rates with Silexan were comparable to placebo and lower than with paroxetine. The earlier Woelk & Schläfke 2010 trial in Phytomedicine (PMID 19962288; DOI 10.1016/j.phymed.2009.10.006) compared Silexan 80 mg/day to lorazepam 0.5 mg/day in GAD; HAM-A reductions were similar, with Silexan showing none of lorazepam’s sedation or dependency signals.

The Active Compounds

Silexan is roughly 36% linalool and 34% linalyl acetate — the two monoterpenes most consistently linked to lavender’s calming effects. It is steam-distilled from Lavandula angustifolia flowers under controlled conditions to fixed pharmacopoeial specifications. Generic lavender oil products vary widely in composition and cannot be assumed to reproduce Silexan’s trial outcomes.

Mechanism

Silexan inhibits voltage-dependent calcium channels in neurons and shows partial agonism at 5-HT1A receptors. Crucially, it does not act at GABA-A receptors, which is consistent with the absence of sedation, dependency, and withdrawal in trial data.

Practical Use

Typical dose is 80 mg once or twice daily, taken with or without food. Onset is usually around 2 weeks, with maximal effect by 6–8 weeks. The most common side effect is eructation with a lavender-like taste, in roughly 1–2% of patients. Available in the US as a supplement (e.g. Calm Aid) and in Europe as a licensed medicine (Lasea). Use in pregnancy is not recommended due to limited safety data; caution is advised in children. As with any anxiolytic, do not stop a prescribed SSRI to switch to Silexan without medical advice.