Supplements · September 30, 2026 · Memios · 15 min read
Lavender, oral
The evidence for oral lavender comes almost entirely from Silexan trials, and nearly all of them were funded by its manufacturer.
TLDR
- Limited evidence. The evidence for oral lavender comes almost entirely from Silexan trials, and nearly all of them were funded by its manufacturer.
- What it is: Lavender is an aromatic evergreen plant native to the Mediterranean region, and it is sold as an oral dietary supplement as well as for aromatherapy and skin use.
- Main use, supported: A meta-analysis of all five completed placebo-controlled Silexan trials found Silexan 80 mg/day reduced anxiety scores more than placebo after ten weeks. (moderate certainty)
- Other use, supported: In a sponsor-run trial in generalised anxiety disorder, Silexan 80 and 160 mg/day reduced anxiety scores more than placebo. (moderate certainty)
- Claim NOT supported by research: An independent systematic review of 15 lavender trials (all routes) found most were of poor quality and concluded no firm conclusions could be drawn. (low certainty)
- Another claim NOT supported: In a small crossover study in healthy volunteers, Silexan 160 mg/day had no clinically relevant effect on five major drug-metabolising liver enzymes. (low certainty)
- Recommended dose: not established. No reference intake exists; lavender is not a nutrient. NCCIH (2025) states lavender is likely safe in the amounts typically used in foods.
- Studied dose (a trial dose, not a recommendation): Silexan 80 mg once daily for 10 weeks in the anxiety trials pooled by Dold et al. 2023. Findings citing that trial: 1 for.
- Upper limit: No tolerable upper intake level has been set by any body in the sources we reviewed.
- What goes wrong: 6 findings on harm. Burping (eructation) was the adverse event that occurred clearly more often with Silexan than with placebo.
- Common myth: Oral lavender is a well-proven, independently confirmed natural anxiety treatment.
What it is
Lavender is an aromatic evergreen plant native to the Mediterranean region, and it is sold as an oral dietary supplement as well as for aromatherapy and skin use. Almost all of the oral research uses one proprietary preparation, Silexan, an active substance made from Lavandula angustifolia and given as an 80 mg capsule once a day. In Germany Silexan is authorised as a medicine for restlessness during anxious mood.
What the research says
The evidence for oral lavender comes almost entirely from Silexan trials, and nearly all of them were funded by its manufacturer. A manufacturer-supported meta-analysis of five placebo-controlled trials (1,213 adults) found lower anxiety scores after ten weeks, but the effect was significant in only four of the five trials and heterogeneity was substantial. Independent reviewers judged the wider lavender literature to be methodologically weak. One sponsored trial found a modest benefit in mild-to-moderate depression. The most common side effect is burping (eructation). Studies found no interaction with oral contraceptives or the major liver enzymes that break down drugs, but there is one case report of difficulty reaching anaesthesia in a patient taking it.
Evidence grade: Limited evidence.
What goes wrong
Burping (eructation) was the adverse event that occurred clearly more often with Silexan than with placebo. (Source 1)
- Randomized trial, Moderate certainty.
- Size: 318 adults.
- Who: adults with mixed anxiety and depressive disorder.
- How long: 70 days.
- Result: Eructation more frequent; rate not given in abstract.
- Funding: industry-funded.
Eructation was the only adverse event with a substantially higher incidence under Silexan.
Across the five pooled trials, serious adverse events and dropouts due to side effects were no more common with Silexan than placebo. (Source 2)
- Meta-analysis, Moderate certainty.
- Size: 606 Silexan vs 600 placebo.
- Who: as above.
- How long: 10 weeks.
- Result: SAEs 6/606 (1.0%) vs 5/600 (0.8%); withdrawal due to AE 2.6% vs 2.3%.
- Funding: industry-funded.
SAEs were reported in a total of 6/606 subjects (1.0%) for Silexan and in 5/600 (0.8%) for placebo.
In the discussion of their manufacturer-funded 2023 meta-analysis, the authors state, citing earlier studies, that side effects attributed to Silexan were mainly mild, short-lived stomach effects such as nausea or burping. (Source 3)
- Meta-analysis, Low certainty.
- Size: narrative statement in discussion.
- Who: as above.
- How long: n/a.
- Result: No rates given in this passage.
- Funding: industry-funded.
Limit of this finding: This is the authors' summary of other studies, not a result of their meta-analysis, and the authors were funded by Schwabe, the maker of Silexan. It gives no rates. Treat it as the authors' view of earlier research rather than an independent safety finding.
AEs attributed to Silexan were mainly limited to mild, transient gastrointestinal effects such as nausea or eructation
A case report described an 18-year-old taking Silexan long term in whom intravenous anaesthesia (propofol, thiopental) failed to achieve the needed depth, raising a possible interaction with anaesthetic drugs. (Source 4)
- Case report, Very low certainty.
- Size: 1 patient.
- Who: 18-year-old undergoing general anaesthesia.
- How long: long-term use.
- Result: Adequate anaesthesia only after inhaled sevoflurane.
- Funding: not stated.
The desired depth of narcosis could only be reached by inhalative induction with sevoflurane after unsuccessful induction attempts using intravenous propofol and thiopental.
Case reports link continuous use of lavender-scented products (topical, not oral) to breast growth in children that resolved when the products were stopped; causation is unproven. (Source 5)
- Case series, Very low certainty.
- Size: 4 children.
- Who: prepubertal children.
- How long: continuous exposure.
- Result: Breast growth resolved after stopping products.
- Funding: independent (NIEHS)
Breast growth dissipated in all patients with discontinuation of the fragranced products.
NCCIH (February 2025) position on safety: oral products may cause diarrhoea, headache, nausea or burping, and may theoretically interact with sedatives. (Source 6)
- Official position, Certainty not rated.
- Size: n/a.
- Who: general public.
- How long: n/a.
- Result: No rates given.
- Funding: government (NIH)
There are theoretical reasons to suspect that lavender might interact with some sedative drugs or herbs
What the evidence supports
A meta-analysis of all five completed placebo-controlled Silexan trials found Silexan 80 mg/day reduced anxiety scores more than placebo after ten weeks. (Source 7)
- Meta-analysis, Moderate certainty.
- Size: 1,213 adults across 5 RCTs.
- Who: adult outpatients with subthreshold anxiety, generalised anxiety disorder or mixed anxiety-depressive disorder.
- How long: 10 weeks.
- Result: Responder rate ratio 1.34 (>=50% HAMA reduction); CGI much/very much improved rate ratio 1.51.
- Funding: industry-funded (Dr. Willmar Schwabe, manufacturer of Silexan)
Based on a ≥ 50% HAMA total score reduction, the responder rate ratio was 1.34 favoring Silexan
A 2019 meta-analysis found oral Silexan 80 mg/day for at least six weeks lowered anxiety scores, but the authors said most included trials carried a high risk of bias. (Source 8)
- Meta-analysis, Low certainty.
- Size: 1,173 participants (HAMA analysis)
- Who: people with anxiety.
- How long: at least 6 weeks.
- Result: HAMA mean difference -2.90 (95% CI -4.86 to -0.95), p = 0.004.
- Funding: not funded (stated)
Hamilton Anxiety Scale mean difference = -2.90 [95% CI -4.86 to -0.95], p = 0.004, 1173 participants
A network meta-analysis of herbal anxiety treatments found Silexan lowered anxiety scores compared with control. (Source 9)
- Meta-analysis, Low certainty.
- Size: 29 trials, 12 herbs.
- Who: adults with diagnosed or subthreshold anxiety.
- How long: varied.
- Result: HAMA MD -3.84 (95% CrI -6.31 to -1.34)
- Funding: not stated.
Silexan (mean difference [MD]: -3.84, 95% credible interval [CrI]: -6.31 to -1.34) displayed a significant effect on anxiety
A 2026 network meta-analysis of anxiolytic drugs, whose authors include Silexan trial investigators, ranked Silexan as effective and as acceptable as placebo. (Source 10)
- Meta-analysis, Certainty not rated.
- Size: 100 trials, 28,637 participants.
- Who: adults with anxiety disorders.
- How long: varied.
- Result: Silexan among four treatments with fewer adverse events than placebo.
- Funding: not stated in abstract.
Notably, silexan was both highly effective and as acceptable as a placebo.
In a sponsor-run trial in generalised anxiety disorder, Silexan 80 and 160 mg/day reduced anxiety scores more than placebo. (Source 11)
- Randomized trial, Moderate certainty.
- Size: 539 adults.
- Who: adults with generalised anxiety disorder.
- How long: 10 weeks.
- Result: HAMA fell 14.1 (160 mg), 12.8 (80 mg), 11.3 (paroxetine), 9.5 (placebo) points.
- Funding: industry-funded (Schwabe staff among authors)
Silexan 160 and 80 mg/d were superior to placebo in reducing the HAMA total score (p < 0.01)
In a sponsor-run trial in mild-to-moderate major depression, Silexan produced a small improvement over placebo, similar to sertraline. (Source 12)
- Randomized trial, Moderate certainty.
- Size: 498 adults.
- Who: adults with mild or moderate major depression.
- How long: 8 weeks.
- Result: MADRS difference vs placebo 2.17 points (95% CI 0.58 to 3.76)
- Funding: industry-funded (Schwabe staff among authors)
absolute differences to placebo of 2.17 (95% confidence interval: 0.58; 3.76) points
What the evidence does not support
An independent systematic review of 15 lavender trials (all routes) found most were of poor quality and concluded no firm conclusions could be drawn. (Source 13)
- Systematic review, Low certainty.
- Size: 15 RCTs.
- Who: people with stress or anxiety; all forms of lavender.
- How long: varied.
- Result: 2 of 15 trials scored 4/5 on the Jadad scale; 13 scored 2 or less; 7 trials favoured lavender on at least one outcome.
- Funding: independent.
Methodological issues limit the extent to which any conclusions can be drawn regarding the efficacy/effectiveness of lavender.
In a small crossover study in healthy volunteers, Silexan 160 mg/day had no clinically relevant effect on five major drug-metabolising liver enzymes. (Source 14)
- Blood level study, Low certainty.
- Size: 16 healthy volunteers.
- Who: healthy adults.
- How long: 11 days.
- Result: 90% CI of AUC ratios within 0.70-1.43 except omeprazole AUC.
- Funding: industry-involved (Schwabe staff among authors)
Repeated silexan (160 mg/day) administration has no clinically relevant inhibitory or inducing effects on the CYP1A2, 2C9, 2C19, 2D6, and 3A4 enzymes in vivo.
Silexan 160 mg/day did not change how a combined oral contraceptive was absorbed or how well it worked. (Source 15)
- Blood level study, Low certainty.
- Size: 24 women.
- Who: healthy fertile women.
- How long: 2 cycles.
- Result: AUC ratios EE 0.97, LNG 0.94.
- Funding: industry-involved (Schwabe staff among authors)
Co-administration of Silexan did not affect the efficacy of a combination oral contraceptive containing EE and LNG and was well tolerated.
In recreational drug users, single doses of Silexan up to 640 mg were rated like placebo for drug liking, unlike lorazepam. (Source 16)
- Randomized trial, Low certainty.
- Size: 40 randomised, 34 evaluable.
- Who: healthy recreational users of CNS depressants.
- How long: single doses.
- Result: Drug liking similar to placebo.
- Funding: industry-funded (Schwabe staff among authors)
both doses of Silexan were rated similar to placebo whereas differences were observed between Silexan and lorazepam
Where the evidence is mixed
In the same meta-analysis, Silexan did not beat placebo in one of the five trials, and the trials disagreed substantially on the size of the effect. (Source 17)
- Meta-analysis, Moderate certainty.
- Size: 5 RCTs.
- Who: as above.
- How long: 10 weeks.
- Result: Significant in 4 of 5 trials; I2 = 72.7%.
- Funding: industry-funded.
Silexan was significantly superior to placebo in 4 out of the 5 individual trials included in the meta-analysis
The meta-analysis was paid for by the manufacturer of Silexan. (Source 18)
- Meta-analysis, Certainty not rated.
- Size: 5 RCTs.
- Who: as above.
- How long: 10 weeks.
- Result: Funding statement.
- Funding: industry-funded.
This research and its publication were financially supported by Dr. Willmar Schwabe GmbH & Co. KG, Karlsruhe, Germany, manufacturer of Silexan.
The same review rated the underlying studies as low quality with a high risk of bias. (Source 19)
- Meta-analysis, Low certainty.
- Size: 65 RCTs in qualitative synthesis.
- Who: people with anxiety.
- How long: varied.
- Result: Quality statement.
- Funding: not funded (stated)
The majority of included RCTs were characterized by a high overall risk of bias.
NCCIH (February 2025) position: an oral lavender oil product might help anxiety, but the research has limitations including lack of independent funding. (Source 20)
- Official position, Certainty not rated.
- Size: n/a.
- Who: general public.
- How long: n/a.
- Result: Position statement.
- Funding: government (NIH)
Studies have suggested that a lavender oil product, taken orally, might be beneficial for anxiety, including anxiety with co-occurring symptoms of depression.
Where the research disagrees
How strong the evidence for oral lavender in anxiety is
- Dold et al. 2023 (manufacturer-supported meta-analysis), meta-analysis of 5 sponsor RCTs: After ten weeks' treatment, Silexan was significantly superior to placebo in reducing the HAMA total score (Source 7)
- Perry et al. 2012 (independent systematic review), systematic review of 15 RCTs: However, further independent replications are needed before firm conclusions can be drawn. (Source 13)
- NCCIH (2025), position: However, the research has several limitations, such as the small sample sizes of the studies, a lack of independent funding and testing, and a lack of participant diversity. (Source 20)
How much
- Reference intake: No reference intake exists; lavender is not a nutrient. NCCIH (2025) states lavender is likely safe in the amounts typically used in foods. (Source 6)
- Upper limit: No tolerable upper intake level has been set by any body in the sources we reviewed. NCCIH (2025) says oral products might be safe short term in the amounts tested in studies. (Source 6)
- Studied: Silexan 80 mg once daily for 10 weeks in the anxiety trials pooled by Dold et al. 2023. (Source 7)
- Studied: Silexan 160 or 80 mg once daily for 10 weeks in generalised anxiety disorder. (Source 11)
- Studied: Single doses of 80 mg and 640 mg in an abuse-potential study. (Source 16)
A common belief, and what the research shows
The belief: Oral lavender is a well-proven, independently confirmed natural anxiety treatment.
What the research shows: The trials of one product, Silexan, are positive, but they were run or funded by its manufacturer. NCCIH notes 'a lack of independent funding and testing', and an independent review concluded 'further independent replications are needed before firm conclusions can be drawn.'
Questions and answers
What is it?
Lavender is an evergreen herb from the Mediterranean. As a supplement it is usually a capsule of lavender oil; most research used one product, Silexan, made from Lavandula angustifolia. (Source 20)
What does it do in the body?
Trials of the Silexan capsule found modestly lower anxiety scores than placebo over about ten weeks, but the trials were funded by the maker and one of five did not show a benefit. (Source 17)
Is it good or bad for you?
In short-term trials it was generally well tolerated; burping was the side effect clearly more common than with placebo. Safety in pregnancy is not known, and it may add to the effect of sedating medicines or anaesthesia. (Source 1)
How do you get more of it?
Lavender is used in small amounts in foods; the trials gave people an 80 mg capsule of Silexan once a day. (Source 6)
If it is harmful, what reduces it?
Does not apply in the usual sense. Oral lavender is not a substance the body needs to clear; side effects in trials were mild stomach effects such as nausea or burping. (Source 3)
Why might someone be low in it or missing it?
Does not apply. Lavender is not a nutrient or a body organism, so there is no deficiency state. (Source 20)
We searched: PubMed searches for lavender deficiency or low status; NCCIH lavender page. Nothing describes a deficiency, because it is not an essential nutrient.
Which whole foods contain it or feed it?
Lavender itself is the food source; it is used as a flavouring in small culinary amounts. (Source 6)
What happens if you do not have it?
Nothing is known to happen. Lavender is not essential, and no deficiency is described in the literature we searched. (Source 20)
We searched: PubMed and NCCIH; no deficiency syndrome exists for a non-essential herb.
How can you test for it?
There is no clinical test for lavender status and none is used in practice. (Source 20)
We searched: PubMed searches (Silexan pharmacokinetics, linalool blood levels); no validated clinical test for lavender intake or status was found.
References
- Eur Neuropsychopharmacol. Efficacy of Silexan in mixed anxiety-depression--A randomized, placebo-controlled trial. 2016. PMID 26718792, DOI 10.1016/j.euroneuro.2015.12.002. Read the source
- Eur Arch Psychiatry Clin Neurosci. Efficacy of Silexan in patients with anxiety disorders: a meta-analysis of randomized, placebo-controlled trials (full text, tolerability and funding). 2023. PMID 36717399, DOI 10.1007/s00406-022-01547-w. Read the source
- Eur Arch Psychiatry Clin Neurosci. Efficacy of Silexan in patients with anxiety disorders (full text, discussion of adverse effects and interactions). 2023. PMID 36717399, DOI 10.1007/s00406-022-01547-w. Read the source
- Anaesthesist. Silexan and narcosis: case report and possibilities of preoperative and perioperative management. 2011. PMID 21728048, DOI 10.1007/s00101-011-1916-x. Read the source
- J Clin Endocrinol Metab. Lavender Products Associated With Premature Thelarche and Prepubertal Gynecomastia: Case Reports and Endocrine-Disrupting Chemical Activities. 2019. PMID 31393563, DOI 10.1210/jc.2018-01880. Read the source
- National Center for Complementary and Integrative Health (NIH). Lavender (safety section). 2025. Read the source
- Eur Arch Psychiatry Clin Neurosci. Efficacy of Silexan in patients with anxiety disorders: a meta-analysis of randomized, placebo-controlled trials. 2023. PMID 36717399, DOI 10.1007/s00406-022-01547-w. Read the source
- Phytomedicine. Effects of lavender on anxiety: A systematic review and meta-analysis. 2019. PMID 31655395, DOI 10.1016/j.phymed.2019.153099. Read the source
- Pharmacol Res. Medicinal herbs for the treatment of anxiety: A systematic review and network meta-analysis. 2022. PMID 35378276, DOI 10.1016/j.phrs.2022.106204. Read the source
- Eur Arch Psychiatry Clin Neurosci. Comparative efficacy and acceptability of anxiolytic drugs for the treatment of anxiety disorders: a systematic review and network meta-analysis. 2026. PMID 40788541, DOI 10.1007/s00406-025-02082-0. Read the source
- Int J Neuropsychopharmacol. Lavender oil preparation Silexan is effective in generalized anxiety disorder--a randomized, double-blind comparison to placebo and paroxetine. 2014. PMID 24456909, DOI 10.1017/S1461145714000017. Read the source
- Eur Arch Psychiatry Clin Neurosci. Lavender oil preparation Silexan is effective in mild-to-moderate major depression: a randomized, placebo- and reference-controlled trial. 2025. PMID 38558147, DOI 10.1007/s00406-024-01783-2. Read the source
- Phytomedicine. Is lavender an anxiolytic drug? A systematic review of randomised clinical trials. 2012. PMID 22464012, DOI 10.1016/j.phymed.2012.02.013. Read the source
- Drug Metab Dispos. Drug cocktail interaction study on the effect of the orally administered lavender oil preparation silexan on cytochrome P450 enzymes in healthy volunteers. 2013. PMID 23401474, DOI 10.1124/dmd.112.050203. Read the source
- Drugs R D. No interacting influence of lavender oil preparation silexan on oral contraception using an ethinyl estradiol/levonorgestrel combination. 2014. PMID 25319228, DOI 10.1007/s40268-014-0065-5. Read the source
- Int J Neuropsychopharmacol. No Abuse Potential of Silexan in Healthy Recreational Drug Users: A Randomized Controlled Trial. 2021. PMID 33300578, DOI 10.1093/ijnp/pyaa064. Read the source
- Eur Arch Psychiatry Clin Neurosci. Efficacy of Silexan in patients with anxiety disorders: a meta-analysis of randomized, placebo-controlled trials (full text). 2023. PMID 36717399, DOI 10.1007/s00406-022-01547-w. Read the source
- Eur Arch Psychiatry Clin Neurosci. Efficacy of Silexan in patients with anxiety disorders (full text, funding statement). 2023. PMID 36717399, DOI 10.1007/s00406-022-01547-w. Read the source
- Phytomedicine. Effects of lavender on anxiety: A systematic review and meta-analysis (discussion). 2019. PMID 31655395, DOI 10.1016/j.phymed.2019.153099. Read the source
- National Center for Complementary and Integrative Health (NIH). Lavender. 2025. Read the source