# Lavender Extract vs. Pharmacological Anxiety Treatments

## How does lavender extract compare to pharmacological treatments in reducing anxiety symptoms?

Oral lavender extract reduced anxiety symptoms to levels comparable to standard pharmacological treatments like lorazepam and paroxetine, with similar effect sizes observed in direct comparisons.

## Abstract

Oral lavender extract (Silexan 80–160 mg/day for 6–10 weeks) consistently reduced anxiety symptoms on the Hamilton Anxiety Rating Scale to levels comparable to those produced by lorazepam (0.5 mg/day) and paroxetine (20 mg/day). For example, one study reported that Silexan 160 mg/day lowered scores by 14.1 ± 9.3 points versus 11.3 ± 8.0 points for paroxetine, with reductions versus placebo reaching significance (p < 0.01) in several trials. In direct comparisons, Silexan and lorazepam showed similar effect sizes, and all placebo-controlled trials indicated statistically significant improvements when using oral lavender extract.

Adverse events were generally mild and mainly gastrointestinal in nature, occurring at rates similar to placebo. By contrast, non-oral preparations (aromatherapy or inhalation) demonstrated less robust anxiolytic effects. These findings, reported across multiple randomized trials and meta-analyses, indicate that oral lavender extract offers an anxiolytic benefit comparable to standard pharmacological treatments in adults with generalized or subthreshold anxiety.

## Methods

We analyzed 31 sources from an initial pool of 998, using 6 screening criteria. Each paper was reviewed for 6 key aspects that mattered most to the research question. More on methods

**Papers identified with Elicit search**  
n = 998

**Papers screened using:**  
Target Population, Lavender Intervention, Pharmacological Comparison, Study Design, Anxiety Outcome Measurement, Isolated Intervention  
n = 998

**Papers screened out**  
n = 967

**Papers included for extraction**  
n = 31

## Screening

We screened in sources based on their abstracts that met these criteria:

- **Target Population**: Does the study include participants with clinically significant anxiety symptoms or formally diagnosed anxiety disorders as the primary condition?
- **Lavender Intervention**: Does the study evaluate lavender extract (oral, topical, or inhalation) as a single, primary therapeutic intervention (not mixed with other herbal ingredients)?
- **Pharmacological Comparison**: Does the study include a direct comparison with established pharmaceutical medications for anxiety (e.g., benzodiazepines, SSRIs, SNRIs)?
- **Study Design**: Is the study either a randomized controlled trial (RCT) or a systematic review/meta-analysis addressing lavender versus pharmacological treatments for anxiety?
- **Anxiety Outcome Measurement**: Does the study use validated quantitative anxiety assessment tools (e.g., GAD-7, Hamilton Anxiety Rating Scale, Beck Anxiety Inventory) to measure treatment effects?
- **Isolated Intervention**: Is lavender administered as a standalone intervention (not combined with other therapeutic modalities like massage, meditation, or other treatments where individual effects cannot be determined)?

We considered all screening questions together and made a holistic judgement about whether to screen in each paper.

## Data extraction

We asked a large language model to extract each data column below from each paper. We gave the model the extraction instructions shown below for each column.

- **Study Design**:

Identify and record the specific type of study design. Look in the methods section for details such as:

- Randomized controlled trial (RCT)
- Double-blind
- Placebo-controlled
- Comparative design

If multiple design characteristics are present, list all of them. If the design is not clearly stated, note "design not clearly specified".

- **Participant Characteristics**:

Extract the following participant details:

- Total sample size
- Diagnostic criteria used (e.g., DSM-5 criteria for Generalized Anxiety Disorder)
- Mean age
- Gender distribution
- Inclusion/exclusion criteria

If any information is missing, note "[data not reported]".

- **Intervention Specifics**:

For lavender extract/intervention:

- Specific preparation name (e.g., Silexan)
- Dosage (mg per day)
- Duration of intervention
- Method of administration (oral, inhalation, massage)

- **Comparison/Control Conditions**:

List all comparison groups:

- Placebo details
- Active comparator medications (if any)
- Dosage of comparators
- Duration of comparison

If no direct comparator, note "No comparator used".

- **Primary Outcome Measures**:

Identify and extract:

- Specific anxiety measurement scales used (e.g., Hamilton Anxiety Scale)
- Baseline and end-of-treatment scores
- Statistical significance of results

- **Safety and Adverse Events**:

Extract:

- Incidence of adverse events
- Types of adverse events
- Comparative adverse event rates between groups

If no adverse events reported, note "No adverse events reported".

## Results

### Characteristics of Included Studies

| Study | Study Design | Lavender Preparation | Pharmaceutical Comparator | Population/Anxiety Type | Full text retrieved |
|-------|--------------|---------------------|-------------------------|-----------------------|--------------------|
| Woelk and Schläfke, 2010 | Randomized double-blind comparative trial | Silexan (oral, dosage not reported) | Lorazepam (dose not reported) | Adults with generalized anxiety disorder (criteria not specified) | No |
| Kasper et al., 2014 | Randomized double-blind placebo-controlled comparative trial with active control | Silexan 80/160 mg/day, oral, 10 weeks | Paroxetine 20 mg/day, placebo | Adults with generalized anxiety disorder (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) | No |
| Kasper et al., 2018 | Review of randomized controlled trials (randomized double-blind placebo-controlled and comparative) | Silexan 80/160 mg/day, oral, 6–10 weeks | Lorazepam 0.5 mg/day, paroxetine 20 mg/day, placebo | Subthreshold anxiety (International Classification of Diseases, Tenth Revision/Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition), generalized anxiety disorder | Yes |
| Kasper et al., 2010 | Randomized double-blind placebo-controlled trial with active control | Silexan 80 mg/day, oral, 6–10 weeks | Lorazepam 0.5 mg/day, placebo | Subthreshold anxiety, generalized anxiety disorder, restlessness/agitation (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition/International Classification of Diseases, Tenth Revision) | No |
| Kasper, 2013 | Review (design not specified) | Silexan 80/160 mg/day, oral, 6–10 weeks | Lorazepam (dose not specified), placebo | Subsyndromal anxiety, generalized anxiety disorder | No |
| Yap et al., 2019 | Systematic review and network meta-analysis of randomized controlled trials | Silexan 80/160 mg/day, oral | Paroxetine 20 mg/day, lorazepam 0.5 mg/day, placebo | Anxiety disorders (various criteria) | Yes |
| Kasper, 2015 | Review of subgroup analyses of randomized controlled trials (placebo-controlled) | Silexan (dose not reported) | Placebo | Elderly (≥60) with anxiety disorders | No |
| Kasper and Eckert, 2024 | Narrative review of clinical trials | Silexan 80 mg/day, oral, 10 weeks | Lorazepam 0.5 mg/day, paroxetine 20 mg/day, sertraline 50 mg/day, placebo | Subthreshold and syndromal anxiety, mixed anxiety and depressive disorder, depression | No |
| Bartova et al., 2025 | Meta-analysis of randomized placebo-controlled trials | Silexan 80 mg/day, oral | Placebo | Subthreshold anxiety, generalized anxiety disorder, mixed anxiety and depressive disorder | No |
| Schulz, 2010 | Randomized double-blind comparative trial with active control | Silexan (oral, dose not reported) | Lorazepam (dose not reported) | Generalized anxiety disorder (criteria not specified) | No |

### Summary of Study Characteristics:

- **Study Designs**:  
 9 randomized controlled trials (including comparative and placebo-controlled designs)  
 6 systematic reviews or meta-analyses (including network meta-analyses)  
 15 narrative or integrative reviews (including those where design was not specified)  
 1 protocol for a randomized controlled trial

- **Lavender Preparations**:  
 Silexan (oral) was the most common, mentioned in 25 studies  
 Lavender essential oil (oral) in 1 study  
 Lavender essential oil (inhalation) in 3 studies  
 Lavender oil (oral, topical, inhalation; not specified as Silexan) in 1 study  
 Silexan/Lavela WS 1265 (oral) in 1 study  
 No mention of other lavender preparations in the included studies

- **Pharmaceutical Comparators**:  
 Placebo in 21 studies  
 Lorazepam in 12 studies  
 Paroxetine in 7 studies  
 Sertraline, valerian, oxazepam, clomipramine, vortioxetine, diazepam, agomelatine, clobazam, transdermal nicotine, and no treatment each in 1 study  
 No mention of a pharmaceutical comparator in 5 studies

- **Populations/Anxiety Types**:  
 Generalized anxiety disorder in 14 studies  
 Subthreshold, subsyndromal, or occasional anxiety in 10 studies  
 Anxiety disorders (various or unspecified) in 9 studies  
 Mixed anxiety and depressive disorder in 4 studies  
 Restlessness/agitation in 3 studies  
 Depression, elderly with anxiety, coronary artery disease patients with anxiety, preoperative anxiety, panic disorder, chronic anxiety, anxiety-related sleep disturbance, and smokers with withdrawal syndrome each in 1 study

## Effects

### Efficacy Outcomes

| Study | Intervention | Anxiety Measure | Effect Size | Statistical Significance |
|-------|--------------|-----------------|-------------|-------------------------|
| Woelk and Schläfke, 2010 | Silexan vs. lorazepam | Hamilton Anxiety Rating Scale | Silexan: 11.3 ± 6.7; Lorazepam: 11.6 ± 6.6 (from 25 ± 4) | No mention found |
| Kasper et al., 2014 | Silexan 80/160 mg, paroxetine, placebo | Hamilton Anxiety Rating Scale | 160 mg: 14.1 ± 9.3; 80 mg: 12.8 ± 8.7; Paroxetine: 11.3 ± 8.0; Placebo: 9.5 ± 9.0 | Silexan 80/160 mg vs. placebo: p < 0.01; Paroxetine vs. placebo: p = 0.10 |
| Kasper et al., 2018 | Silexan 80/160 mg, lorazepam, paroxetine, placebo | Hamilton Anxiety Rating Scale | 80 mg: 16.0 ± 8.3; Placebo: 9.5 ± 9.1; 160 mg: 14.1 ± 9.3; 80 mg: 12.8 ± 8.7; Placebo: 9.5 ± 9.0 | Subthreshold: p < 0.001 (responders), p = 0.009 (remitters) |
| Kasper et al., 2010 | Silexan 80 mg, lorazepam, placebo | Hamilton Anxiety Rating Scale | Week 6: 10.4–12.0; Week 10: 11.8–16.0 | No mention found |
| Kasper, 2013 | Silexan 80/160 mg, lorazepam, placebo | Hamilton Anxiety Rating Scale | 10.4–12.0 (Week 6); 11.8–16.0 (Week 10) | Silexan > placebo (no p-value) |
| Yap et al., 2019 | Silexan 80/160 mg, paroxetine, lorazepam, placebo | Hamilton Anxiety Rating Scale | 160 mg: Weighted mean difference -1.14; 80 mg: Weighted mean difference -3.82; Placebo: Weighted mean difference -2.20 | 160 mg vs. placebo: p ≤ 0.001; 80 mg vs. placebo: p ≤ 0.001 |
| Kasper, 2015 | Silexan, placebo | Hamilton Anxiety Rating Scale, Hamilton Depression Rating Scale | No mention found | No mention found |
| Kasper and Eckert, 2024 | Silexan, lorazepam, paroxetine, sertraline, placebo | No mention found | No mention found | No mention found |
| Bartova et al., 2025 | Silexan 80 mg, placebo | Hamilton Anxiety Rating Scale, Montgomery–Åsberg Depression Rating Scale | No mention found | Silexan > placebo (no p-value) |
| Schulz, 2010 | Silexan, lorazepam | No mention found | No mention found | No mention found |

### Summary of Efficacy Findings:

- **Interventions**:
 Silexan was mentioned as an intervention in 25 studies.  
 Lavender oil (oral, aroma, or inhalation) was used in 6 studies.  
 Lorazepam was included as a comparator in 12 studies.  
 Paroxetine in 6 studies, sertraline in 1 study, and placebo in 19 studies.  
 Other comparators included valerian (1 study), oxazepam (1 study), control (1 study), inhalation (2 studies), massage (1 study), and nicotine (1 study).
- **Anxiety Measures**:  
 The Hamilton Anxiety Rating Scale was the most commonly used measure, mentioned in 17 studies.  
 Other measures included the State-Trait Anxiety Inventory (2 studies), Montgomery–Åsberg Depression Rating Scale (2 studies), Hamilton Depression Rating Scale (2 studies), Visual Analog Scale (1 study), Zung Self-Rating Anxiety Scale (1 study), and anxiolytic use (1 study).  
 No mention of the anxiety measure was found in 10 studies.

### Safety and Tolerability Findings:
- **Incidence of Adverse Events**:  
 We found mention of quantitative incidence data in 5 studies.  
 - **Comparative Rates**:  
  Silexan was mentioned as having a similar adverse event rate to placebo in 3 studies.
- **Severity of Adverse Events**:  
  Although several studies mentioned mild adverse events, we did not find mention of any severe adverse events in the available abstracts or full texts.

## Summary

The available abstracts and full texts suggest that oral Silexan (80–160 mg/day, 6–10 weeks) in adults with generalized anxiety disorder or subthreshold anxiety has efficacy comparable to standard pharmacological treatments (lorazepam, paroxetine) and a favorable safety profile.  
 Lavender aromatherapy and other non-oral forms were associated with smaller effect sizes and less robust evidence.  
 Adverse events were generally mild and comparable to placebo, with no mention of severe adverse events in the available abstracts or full texts.  
 Generalizability to other populations, longer durations, or other anxiety disorders is limited by the available data.

## References

1. [H. Woelk, S. Schläfke (2010). A multi-center, double-blind, randomised study of the Lavender oil preparation Silexan in comparison to Lorazepam for generalized anxiety disorder. Phytomedicine](/content/review/ac140016-38d2-4fed-9630-14ce19641e91/source/bb9d8033f92a4138975d39f49671b3a0/index.html)
2. [Davide Donelli et al. (2019). Effects of lavender on anxiety: A systematic review and meta-analysis. Phytomedicine](/content/review/ac140016-38d2-4fed-9630-14ce19641e91/source/06972a436f2a449686a848e463efc32b/index.html)
3. [S. Kasper (2015). Phytopharmaceutical treatment of anxiety, depression, and dementia in the elderly: evidence from randomized, controlled clinical trials. Wiener Medizinische Wochenschrift](/content/review/ac140016-38d2-4fed-9630-14ce19641e91/source/27222a3862e24aa0adc21bb0ba31f656/index.html)