Remedy · herb & leaf
Holy basil (tulsi): what the evidence says about stress
A sacred Ayurvedic basil drunk as tulsi tea. A handful of small placebo-controlled trials report lower stress scores, but the evidence base is thin and mostly tests branded extracts.
By the editors of Alimentotherapy Last reviewed 4 min read Not medical advice
Holy basil (tulsi)
Ocimum tenuiflorum (O. sanctum)
Best-supported use: Self-rated stress
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The short answer
Two small placebo-controlled trials of holy basil extracts, in 150 and 100 adults, found lower stress symptom scores after 6 to 8 weeks than placebo Saxena 2012; Lopresti 2022. That is too little, from too few independent groups, to grade above limited, and no trial has tested tulsi tea as most people drink it.
The evidence, use by use
Each claim graded on human studies only. How we grade
| Use | Grade | What the research found |
|---|---|---|
| Self-rated stress | Limited | In an 8-week trial of 100 stressed adults, 125 mg of extract twice a day lowered Perceived Stress Scale scores and hair cortisol more than placebo. A 6-week trial of 150 adults on 1,200 mg a day of another extract reported fewer stress symptoms. Lopresti 2022; Saxena 2012 |
| Sleep quality in stressed adults | Limited | The same 8-week trial found better scores on an insomnia questionnaire, but the authors say gold-standard objective sleep measures are needed to confirm it. Lopresti 2022 |
| Blood sugar in type 2 diabetes | Limited | One small single-blind crossover trial of holy basil leaves found fasting blood glucose fell by 21.0 mg/dL (17.6%) compared with placebo leaves. It has not been repeated in larger, double-blind trials. Agrawal 1996; Jamshidi 2017 |
What holy basil is
Holy basil, or tulsi, is native to the Indian subcontinent and is highly revered in Ayurvedic and Siddha medicine Jamshidi 2017. It is a different species from the sweet basil used in Italian cooking (Ocimum basilicum). In the US it is sold mostly as tulsi tea and as capsules of leaf extract, often labeled as an "adaptogen", a traditional term for herbs thought to help the body resist stress.
Stress: what the trials found
A 2017 systematic review found 24 human studies of tulsi reporting effects on metabolism, heart health, immunity and thinking. All reported favorable results and none reported significant adverse eventsJamshidi 2017. The review did not pool the results, and a body of research in which every study is positive deserves caution until larger, independent trials report.
The two placebo-controlled stress trials are the most useful:
- In 2012, 150 adults with general stress symptoms took an extract (1,200 mg of actives a day) or placebo for 6 weeks. Total stress symptom scores fell more in the extract group, including forgetfulness, exhaustion and recent sleep problems Saxena 2012.
- In 2022, 100 stressed adults aged 18 to 65 took 125 mg of a different extract twice a day or placebo for 8 weeks. Perceived Stress Scale scores and insomnia scores improved more on the extract, hair cortisol was lower at week 8, and cortisol and blood pressure rose less during a lab stress testLopresti 2022.
Both trials tested branded extracts, and results from one extract do not carry over to another, or to tea. For the habits with stronger evidence, see our stress page, and for the better-studied alternative, ashwagandha vs holy basil.
Blood sugar
In a small randomized, single-blind crossover trial in people with type 2 diabetes, holy basil leaves lowered fasting blood glucose by 21.0 mg/dL and after-meal glucose by 15.8 mg/dL compared with placebo leavesAgrawal 1996. It is one old, small study. The practical point is a caution: if you take diabetes medicine, regular holy basil supplements could add to its effect, so check your readings and tell your clinician.
Tulsi tea
In the kitchen
Tulsi tea is brewed like any leaf tea: a teaspoon or a tea bag of dried leaf in a cup of just-boiled water, covered, for several minutes. It is naturally caffeine-free unless blended with black or green tea, so check the label if you drink it in the evening.
A warm, caffeine-free cup is a reasonable part of winding down even though no trial has tested the tea for stress. iHerb carries tulsi teas, including single-ingredient ones. See herbal infusions for brewing basics.
Before you try it: safety and interactions
Who should avoid it or ask first
- You take diabetes medicine: holy basil leaves lowered blood glucose in a small trial, so monitor and tell your clinician.
- You are about to have surgery or take several prescription drugs: tell your clinician about any herbal supplement.
- You need long-term safety data: there are no long-term human studies.
Possible side effects
- No significant adverse events were reported in the reviewed human studies, but most were small and short.
- Trials of extracts for 6 to 8 weeks reported it was well tolerated.
Pregnancy and breastfeeding
We found no reliable human safety data for holy basil supplements in pregnancy or breastfeeding, so avoid extracts then and ask your midwife or doctor about the tea. Jamshidi 2017; Agrawal 1996; Lopresti 2022
Medicine interactions
We found no well-documented medicine interactions for holy basil (tulsi) at food amounts. That is not proof there are none: tell your pharmacist about any herb or supplement you take.
Check another food or medicine in the interactions list.
Common questions
Does holy basil reduce stress?
Possibly, but the evidence is limited. Two small placebo-controlled trials of holy basil extracts, with 150 and 100 adults over 6 to 8 weeks, found lower stress scores than placebo. No trial has tested tulsi tea for stress.
Is holy basil the same as the basil I cook with?
No. Holy basil or tulsi is Ocimum tenuiflorum (also called Ocimum sanctum). Sweet basil used in cooking is Ocimum basilicum, a different species, and the trials on this page do not apply to it.
Can holy basil lower blood sugar?
In one small 1996 crossover trial in people with type 2 diabetes, holy basil leaves lowered fasting blood glucose by 21.0 mg/dL compared with placebo leaves. If you take diabetes medicine, tell your clinician before using holy basil supplements and watch your readings.
Sources
Primary research and government sources, each checked on the date this page was reviewed.
- PubMedJamshidi N, Cohen MM. The Clinical Efficacy and Safety of Tulsi in Humans: A Systematic Review of the Literature. Evid Based Complement Alternat Med. 2017. PMID 28400848.
- PubMedLopresti AL, et al. A randomized, double-blind, placebo-controlled trial investigating the effects of an Ocimum tenuiflorum (Holy Basil) extract (Holixer(TM)) on stress, mood, and sleep in adults experiencing stress. Front Nutr. 2022. PMID 36185698.
- PubMedSaxena RC, et al. Efficacy of an Extract of Ocimum tenuiflorum (OciBest) in the Management of General Stress: A Double-Blind, Placebo-Controlled Study. Evid Based Complement Alternat Med. 2012. PMID 21977056.
- PubMedAgrawal P, et al. Randomized placebo-controlled, single blind trial of holy basil leaves in patients with noninsulin-dependent diabetes mellitus. Int J Clin Pharmacol Ther. 1996. PMID 8880292.
Keep reading
- GoalFood and stress: what helps, and what the herb trials showEveryday stress responds best to exercise, sleep and relaxation practice, plus cutting back on caffeine and alcohol. Anxiety disorders need psychotherapy or medication; herb trials are small.
- RemedyAshwagandhaAn Ayurvedic root sold as a stress supplement. Short trials point to lower stress scores and a small sleep benefit, but the studies are small and rare liver injury has been reported.
- ComparisonAshwagandha vs holy basilBoth are Ayurvedic herbs sold as adaptogens for stress. Ashwagandha has a dozen trials and a moderate grade; holy basil has two small trials of branded extracts. Ashwagandha also has more safety cautions.
- Kitchen practiceHerbal infusionsSteeping a leaf or simmering a root is the oldest way to take a plant. Most common kitchen herbs are safe as tea; a few are not, and the label on the box tells you less than you might think.
- ToolFood and drug interactionsCheck a remedy or food against common medicines.