Lavender

Metadata

Approved Indications

Commission E (Germany)

• Approved: Internally for mood disturbances such as restlessness or insomnia, functional abdominal complaints (nervous stomach irritation, Roehmheld syndrome, meteorism, nervous intestinal discomfort)
• Approved: Externally for functional circulatory disorders (balneotherapy)

ESCOP

• Approved: Internal use for relief of anxiety and restlessness; improvement of sleep disturbance related to anxiety
• Approved: External use (balneotherapy) for functional circulatory disorders

EMA/HMPC

• Traditional use registration: Silexan registered as a traditional herbal medicine for “relief of mild symptoms of mental stress” and “to aid sleep” — but in practice, the clinical data strongly supports anxiolytic indications
• Note: The “traditional use” classification for Silexan is somewhat misleading — it has considerably more clinical evidence than most “well-established use” herbal medicines. The traditional use pathway was likely chosen for regulatory convenience.

Agreement/Disagreement

Commission E and ESCOP cover broader traditional lavender uses (including GI and topical). The EMA registration for Silexan specifically focuses on anxiety/stress. The clinical evidence for Silexan goes well beyond what the formal regulatory classification suggests.

Conditions Treated

Primary (Strong Evidence)

• Generalized anxiety disorder (GAD) — Head-to-head equivalence with lorazepam and paroxetine
• Subthreshold anxiety disorder (anxiety symptoms not meeting full DSM criteria for GAD)
• Mixed anxiety and depressive disorder

Secondary (Moderate-Emerging Evidence)

• Mild-to-moderate major depression — A 2024 RCT demonstrated Silexan’s efficacy in MDD [Source: Springer s00406-024-01783-2]
• Somatic symptoms of anxiety — Silexan reduces both psychic and somatic HAMA subscores
• Restlessness and sleep disturbance associated with anxiety (secondary to anxiolysis rather than direct sedation)

Traditional/External Use

• Aromatic therapy (inhalation) for relaxation
• Bath additive (balneotherapy) for functional circulatory disorders
• Topical for minor skin irritation

Mechanism of Action

Silexan has a novel mechanism distinct from other anxiolytic herbs (which typically work through GABAergic pathways):

Primary Mechanism: Voltage-Gated Calcium Channel (VGCC) Inhibition

• Silexan moderately inhibits voltage-gated calcium channels, specifically:
  • T-type (Cav3) — Primary target
  • N-type (Cav2.2) — Secondary target
  • P/Q-type (Cav2.1) — To a lesser extent
• This is conceptually similar to pregabalin (Lyrica), which is also an anxiolytic VGCC modulator
• Critical difference from pregabalin: Silexan does NOT bind to the alpha-2-delta-1 subunit (the pregabalin binding site on P/Q-type channels). Instead, it acts through a different mechanism at different channel subtypes.
• Clinical significance of this difference: Silexan is free of sedative/hypnotic side effects and has no abuse potential — both significant advantages over pregabalin

Secondary Mechanisms

1. Serotonin receptor modulation: Reduces serotonin-1A receptor binding, which may contribute to anxiolysis
2. NMDA receptor: Potential inhibition of NMDA receptor signaling [NEEDS-RESEARCH]
3. No GABAergic activity: Unlike benzodiazepines, valerian, kava, and other sedative herbs, Silexan does NOT significantly modulate GABA-A receptors. This explains why it is non-sedating.

Pharmacological Profile Summary

Clinical Evidence Summary

Meta-Analysis (Yap et al., 2023)

• Five double-blind, randomized, placebo-controlled trials
• Total n = 1,213 (Silexan 80 mg/day vs. placebo, 10-week treatment)
• Silexan was significantly superior to placebo in reducing HAMA total score
• Significant improvement in both psychic anxiety and somatic anxiety subscores
• [Source: PMC10465640]

Key Head-to-Head Comparisons

Silexan vs. Lorazepam (Woelk & Schlafke, 2010)

• Design: Multicenter, double-blind, randomized, active-controlled, 6 weeks
• n = 77 patients with GAD
• Silexan 80 mg/day vs. Lorazepam 0.5 mg/day
• Result: Comparable reduction in HAMA total scores. Silexan was non-inferior to lorazepam.
• Significance: Equivalent anxiolysis without sedation, cognitive impairment, or abuse potential
• [Source: PubMed 19962288]

Silexan vs. Paroxetine (Kasper et al., 2014)

• Design: Randomized, double-blind, placebo-controlled with active reference, 10 weeks
• n = 539 patients with GAD
• Silexan 80 mg/day vs. Silexan 160 mg/day vs. Paroxetine 20 mg/day vs. Placebo
• Result: Silexan 80 mg/day was significantly superior to placebo and as effective as paroxetine 20 mg/day. Silexan 160 mg/day showed additional benefit.
• [Source: Int J Neuropsychopharmacol 2014;17(6):859-869]

Silexan in Subthreshold Anxiety (Kasper et al., 2010)

• Design: DBRPCT, 10 weeks
• n = 221 patients with subthreshold anxiety (ICD-10: Neurasthenia/F48.0)
• Silexan 80 mg/day vs. Placebo
• Result: Significant reduction in HAMA total score; 62.5% responders vs. 42.7% placebo
• [Source: PubMed 21170695]

Depression Evidence (2024)

• A randomized, placebo- and reference-controlled trial demonstrated Silexan’s efficacy in mild-to-moderate major depression
• [Source: European Archives of Psychiatry and Clinical Neuroscience, 2024]
• This represents a significant expansion of Silexan’s evidence base beyond anxiety

Long-Term Safety Data (2025)

• Real-world data analysis confirmed Silexan is well-tolerated for long-term use in adults and safe for adolescent treatment
• [Source: Springer s00406-025-01967-4]

European vs. US/Anglophone Consensus

US Knowledge Gap

Silexan/Lasea represents perhaps the largest gap between European and US awareness in phytotherapy. In Germany it is a mainstream anxiolytic option; in the US it is virtually unknown to both physicians and patients.

Safety Profile

Contraindications

• Known hypersensitivity to lavender or other Lamiaceae
• No other absolute contraindications in current monographs

Drug Interactions

• None known. This is a major advantage. Silexan does not appear to significantly interact with CYP450 enzymes or P-glycoprotein.
• No known pharmacokinetic or pharmacodynamic interactions with other medications
• Can theoretically be combined with SSRIs, benzodiazepines, or other treatments without interaction concerns [but limited formal data on combinations]

Side Effects

• Most common: GI complaints (eructation/burping with lavender taste, nausea) — generally mild and transient
• Allergic/hypersensitivity reactions: Rare
• NOT sedating: This is a key clinical differentiator. No drowsiness, no cognitive impairment, no psychomotor impairment
• No abuse potential
• No withdrawal symptoms on discontinuation
• No dependence formation

Pregnancy and Lactation

• Pregnancy: Insufficient data. No specific safety concerns identified but not recommended due to lack of adequate studies. EMA: Not recommended.
• Lactation: Insufficient data. Not recommended.
• Adolescents (12+): 2025 real-world data analysis supports tolerability in adolescents

Clinical Dosage

Standard Anxiolytic Dose

• Silexan (Lasea): 80 mg once daily (one soft gelatin capsule)
• Higher dose: 160 mg/day showed additional benefit in the Kasper 2014 trial but standard recommendation remains 80 mg/day
• Taken orally, with or without food

Duration

• Clinical trials used 6-10 week treatment periods
• Long-term use data (real-world) supports safety for extended periods
• No maximum duration specified

Other Lavender Preparations (Traditional)

• Essential oil (inhalation): 1-4 drops; aromatherapy evidence is separate and weaker than Silexan oral data
• Tea: 1-2 teaspoons dried flowers per cup; traditional use for relaxation
• Bath additive: 20-100 g dried flowers or equivalent essential oil in bath water

Important Note

The clinical evidence applies specifically to Silexan (WS 1265), a precisely standardized product. Generic lavender essential oil capsules may not be equivalent. The composition, purity, and standardization of the oil matter.

Sources

• Yap WS et al. Efficacy of Silexan in patients with anxiety disorders: a meta-analysis of randomized, placebo-controlled trials. Eur Arch Psychiatry Clin Neurosci. 2023. PMC10465640
• Woelk H, Schlafke S. A multi-center, double-blind, randomised study of the Lavender oil preparation Silexan in comparison to Lorazepam for generalized anxiety disorder. Phytomedicine. 2010;17(2):94-99. PubMed 19962288
• Kasper S et al. Lavender oil preparation Silexan is effective in generalized anxiety disorder — a randomized, double-blind comparison to placebo and paroxetine. Int J Neuropsychopharmacol. 2014;17(6):859-869
• Kasper S et al. Efficacy and safety of silexan in subthreshold anxiety disorder. PubMed 21170695
• Schuwald AM et al. Lavender Oil-Potent Anxiolytic Properties via Modulating Voltage Dependent Calcium Channels. PLoS One. 2013. PMC3639265
• Silexan pharmacological basis: ScienceDirect S0197018620302904
• Silexan in depression (2024): Springer s00406-024-01783-2
• Silexan long-term/adolescent safety (2025): Springer s00406-025-01967-4
• Kasper S et al. Silexan in anxiety, depression, and related disorders: pharmacological background and clinical data (2024). Springer s00406-024-01923-8

Connections

• Compare with other anxiolytics: Kava (also strong evidence but regulatory issues), St Johns Wort (for depression overlap)
• VGCC mechanism is unique among herbs in this collection — no overlap with GABAergic herbs (Valerian, Passionflower, Hops)
• The absence of drug interactions makes Silexan particularly valuable compared to St. John’s Wort
• Emerging depression evidence connects to St Johns Wort