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Holy Basil

Holy basil (Ocimum tenuiflorum)

Holy basil, also called tulsi, is Ocimum tenuiflorum leaf or aerial-part material used in Ayurveda. Its limited human evidence is most relevant to perceived stress and subjective sleep-quality measures, not direct memory or focus benefits. A 2022 trial of one branded standardized extract reported better perceived-stress scores after 8 weeks. Compare species, plant part, extract ratio and dose before assuming powders, teas and extracts are comparable.

CalmRelaxationSleep SupportStress ResilienceMood SupportHpa Axis RelatedCortisol Related
Updated August 2026/4 min read/4 citations
Reviewed by the NootropicsIndex editorial team.Method: prioritize cited human research and official safety or regulatory sources; compare retailer-listed prices without endorsing products.Affiliate disclosure
01

What is it?

What holy basil is

1

Holy basil is Ocimum tenuiflorum, a botanical also known as tulsi. Supplements may use leaf powder, tea, tincture or standardized extract, and those forms should not be assumed equivalent.

Stress support is the main nootropics-adjacent angle2
Holy basil belongs in a nootropics database mainly because buyers compare it for stress resilience and calm. The direct memory, focus and mental-energy evidence is much weaker.

Human evidence is promising but heterogeneous

2

The 2017 systematic review found 24 human studies and no significant adverse events, but it also emphasized that dose, dose form and target populations need more clarification. This makes strong product-to-product comparisons risky.

Standardized extract stress trial

4

The 2022 randomized trial used 125 mg standardized Ocimum tenuiflorum extract twice daily for 8 weeks in adults experiencing stress. It reported better perceived-stress scores and cortisol-related markers versus placebo, with no major adverse effects.

Small, single-arm study3
A 2009 single-arm study gave 35 participants a 500 mg leaf-extract capsule twice daily for 60 days and recorded rating-scale changes. Without a comparator, it provides cautious context only and cannot establish broad cognition benefits or a general dose conversion.
02

Names, aliases and forms

Common NameHoly basil
Traditional NameTulsi
Latin NameOcimum tenuiflorum
Taxonomic SynonymOcimum sanctum
Plant PartLeaf / aerial-part extract
Extract NameHolixer
03

Potential effects and evidence map

A 2017 systematic review described heterogeneous human studies and called for better dose, form and population data. A 2022 double-blind trial of one branded standardized extract, given as 125 mg twice daily for 8 weeks, reported better perceived-stress and subjective sleep-quality measures than placebo in adults experiencing stress; the trial had industry funding. Direct cognition evidence is weak, and these findings do not generalize to teas, powders or differently standardized products.

Effect domainMagnitudeGrade
Stress resilience4
CumulativeConfidence: Medium

A standardized extract showed better perceived-stress scores and cortisol-related stress markers over 8 weeks in stressed adults.

Note Useful stress-support signal, but still a single branded-extract RCT plus broader heterogeneous literature.

2/5
C
Calm / relaxation3
CumulativeConfidence: Low

Small human trials suggest a calm-support signal, but study designs and products vary.

Note The older Ocimum sanctum trial was small and not enough for strong claims.

2/5
C
Mood / wellbeing4
CumulativeConfidence: Low

Mood-related measures may improve in stressed-adult contexts, but the evidence is not robust enough for a strong mood claim.

Note Use stress-context framing rather than broad mood promises.

1/5
C
Sleep quality4
CumulativeConfidence: Low

A standardized extract improved subjective rest-quality scores in one 8-week adult trial.

Note Do not generalize to all holy basil products or acute use.

1/5
C
Focus / attention3
UnknownConfidence: Low

Direct attention evidence is weak and comes mainly from small or indirect clinical measures.

Note Avoid presenting holy basil as a focus supplement.

1/5
D
Memory / learning2
UnknownConfidence: Medium

No meaningful human memory or learning evidence was identified.

Note Stress benefits should not be reframed as memory enhancement.

0/5
E
Mental energy / wakefulness2
UnknownConfidence: Medium

No reliable wakefulness or mental-energy evidence was identified.

Note Avoid energizing claims.

0/5
E
04

Typical dosages and timing

Typical
250-1000 mg/day
Not a recommendation
Lower bound
250 mg/day
Profile value
Upper bound
1000 mg/day
Profile value
Study regimen4125 mg twice daily

The cited studies used study-specific daily amounts: 250 mg/day for one branded standardized extract and 1000 mg/day in a small single-arm leaf study. These are study contexts, not a universal consumer dose range or a conversion for tea, powder, tincture or other extracts.

05

Timing & effect horizon

Effect horizonCumulative
Cumulative
Study window4Cumulative
8 weeks
Study duration context4

The strongest modern randomized trial studied a standardized extract for 8 weeks. This is the study window, not a measurement of same-day onset or an individual course.

06

Safety, side effects and risk profile

Short-term adult tolerability data2
The 2017 review reported no significant adverse events in its included human studies, and the 2022 standardized-extract trial reported no major adverse effects over 8 weeks. This supports a minimal base-risk assessment only for typical oral use in generally healthy adults; it does not establish long-term, pregnancy, nursing or medicine-interaction safety.
Pregnancy, nursing and care-context caution2
The cited adult studies do not establish casual-use safety during pregnancy or nursing, or alongside prescription medicines. For ongoing health conditions or medication use, use this page as information rather than a substitute for clinician-directed care.
Evidence uncertainty2
Confidence: High

Human studies are heterogeneous in product, dose, population and outcome measures.

Note The 2017 review called for better dose, form and population clarification.

2/5
C
Pregnancy / lactation caution2
Confidence: Low

The cited adult studies do not provide enough pregnancy or nursing safety data for casual use.

Note Keep this as a general botanical caution, not a claim of known harm.

2/5
D
GI discomfort4
Confidence: Low

The 2017 review and 2022 RCT did not report major adverse effects, but individual tolerability can differ.

Note Low general tolerability concern at studied oral doses.

1/5
C
Interaction risk2
Confidence: Low

The cited human studies do not establish safe use alongside prescription medicines.

Note This is an evidence gap, not evidence of a specific interaction or a reason to raise the healthy-adult base risk.

1/5
D
07

Practical buying and quality notes

  • Compare species name, plant part, extract ratio, marker testing, serving size and form. A tea, whole-leaf powder, tincture and branded standardized extract may have very different dose math.
08

FAQ

Is holy basil a nootropic?

4

Only indirectly. The clearest human signal involves perceived stress and subjective sleep-quality measures, not direct memory, focus or mental-energy enhancement.

What holy basil dose is commonly studied?

4

One 2022 trial of a branded standardized extract used 125 mg twice daily for 8 weeks. This is a study dose for that extract, not a dosing conversion for leaf powder, tea, tincture or other extracts.

How long was holy basil studied for stress support?

4

The 2022 trial lasted 8 weeks. This is a trial duration, not a promise of an effect timeline or a suggested cycle.

09

References

  1. NCBI Taxonomy Browser. Ocimum tenuiflorum, taxonomy ID 204149.
  2. Jamshidi N, Cohen MM. The Clinical Efficacy and Safety of Tulsi in Humans: A Systematic Review of the Literature. Evidence-Based Complementary and Alternative Medicine. 2017.
  3. Bhattacharyya D, Sur TK, Jana U, Debnath PK. Controlled programmed trial of Ocimum sanctum leaf on generalized anxiety disorders. Nepal Medical College Journal. 2009;10(3):176-179.
  4. Lopresti AL, Smith SJ, Metse AP, Drummond PD. A randomized, double-blind, placebo-controlled trial investigating the effects of an Ocimum tenuiflorum (Holy Basil) extract (Holixer) on stress, mood, and sleep in adults experiencing stress. Frontiers in Nutrition. 2022.
Note

This page is informational and summarizes available evidence. It is not medical advice, a recommendation, or a substitute for guidance from a qualified clinician.