Holy Basil
Also known as: Ocimum sanctum, Tulsi, Ocimum tenuiflorum
A randomized trial of holy basil leaves in people with non‑insulin‑dependent diabetes reported significant reductions in fasting and postprandial glucose. Two controlled human trials using multi‑herb preparations that included holy basil observed enhanced natural killer cell activity and faster recovery with lower inflammatory markers in COVID‑19 patients, but those studies do not isolate the effect of holy basil alone. Topical use (essential oil in a cream) showed antioxidant effects on skin in a cosmetic trial rather than oral effects.
Last reviewed: 2026-10-14 · 3 indexed studies
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Overview
Holy basil (Ocimum spp., often called tulsi) is a traditional medicinal herb used as a tea, leaf preparation or tablet. Human trials report modest effects on blood glucose when leaves were given to people with type 2 diabetes, and trials using preparations that include holy basil report immunomodulatory and anti-inflammatory effects, but single‑ingredient evidence is limited.
Mechanism & Function
Mechanism of Action
Reported mechanisms in the provided studies are indirect: antioxidant activity (demonstrated for essential oils in vitro and in a topical formulation) and modulation of immune activity (enhanced NK cell activity in a multi‑herb tea; lower inflammatory markers in a multi‑compound Ayurvedic regimen). The glucose‑lowering effect was observed clinically after oral leaf administration, but the specific biochemical pathway was not defined in the supplied abstracts.
Physiological Role
Not established as an essential nutrient. Traditional use and trial data suggest roles in peripheral glucose regulation and modulation of innate immune responses, likely via antioxidant and phytochemical actions.
Primary Pathways
Performance / Health Relevance
Evidence is limited for direct performance benefits. Potential relevance lies in general health support (immune function) and metabolic modulation rather than acute ergogenic effects.
Evidence Review
No meta-analyses or systematic reviews indexed for this ingredient yet.
Dimensions marked N/A have no indexed evidence of that class. They are shown as unavailable rather than scored.
Practical Use & Dosage
- Minimum Effective Dose
- Not established for single‑ingredient use; one trial of a multi‑ingredient regimen used 0.5 g Tulsi Ghanvati twice daily as part of the combination.
- Optimal Range
- Not established
- Upper / Caution Level
- Not established
- Timing
- In reported trials, preparations were given either 30 minutes post‑meal or twice daily; timing likely depends on formulation (tea, tablet, leaf).
- Best Format
- Leaf preparations, tea, standardized tablets; topical essential oil in skincare (not an oral format).
- Bioavailability
- No bioavailability data provided in the supplied abstracts.
- Absorption Considerations
- Not established from the provided studies.
Safety & Interactions
Side Effects
- •No adverse effects specifically reported in the supplied abstracts
Contraindications
- Not established in the provided trials
Drug Interactions
- •Not reported in provided abstracts; potential interactions with glucose‑lowering medications are plausible given observed glucose effects and should be monitored clinically.
Who Should Avoid
- •Not established from provided data; caution advised in people on antidiabetic therapy until effects on glucose are clarified.
Monitoring
If used by people with diabetes, monitor blood glucose when starting or changing holy basil use due to reported glucose‑lowering effects in one trial.
Frequently Asked Questions
Auto-generated from indexed evidence — dosage, safety, interactions, and more.
When is Holy Basil typically used or indicated?
Holy Basil is most commonly used for: Support for blood glucose control (adjunct), Immune support / modulation, General antioxidant support, Herbal tea / botanical supplement. Not established as an essential nutrient. Traditional use and trial data suggest roles in peripheral glucose regulation and modulation of innate immune responses, likely via antioxidant and phytochemical actions.
How does Holy Basil work?
Reported mechanisms in the provided studies are indirect: antioxidant activity (demonstrated for essential oils in vitro and in a topical formulation) and modulation of immune activity (enhanced NK cell activity in a multi‑herb tea; lower inflammatory markers in a multi‑compound Ayurvedic regimen). The glucose‑lowering effect was observed clinically after oral leaf administration, but the specific biochemical pathway was not defined in the supplied abstracts.
What is the recommended dose of Holy Basil?
The optimal range is Not established. with a minimum effective dose of Not established for single‑ingredient use; one trial of a multi‑ingredient regimen used 0.5 g Tulsi Ghanvati twice daily as part of the combination.. Best taken: In reported trials, preparations were given either 30 minutes post‑meal or twice daily; timing likely depends on formulation (tea, tablet, leaf).. Upper / caution level: Not established.
What are the side effects of Holy Basil?
Reported side effects include: No adverse effects specifically reported in the supplied abstracts. Monitoring: If used by people with diabetes, monitor blood glucose when starting or changing holy basil use due to reported glucose‑lowering effects in one trial.
Does Holy Basil interact with medications?
Known or theoretical interactions: Not reported in provided abstracts; potential interactions with glucose‑lowering medications are plausible given observed glucose effects and should be monitored clinically.. Always check with a clinician before combining with prescription medication.
Who should avoid Holy Basil?
Holy Basil is generally not recommended for: Not established from provided data; caution advised in people on antidiabetic therapy until effects on glucose are clarified.; and Not established in the provided trials.
How strong is the evidence for Holy Basil?
Evidence level: Moderate (overall score 59/100), based on 3 indexed studies on SuppIndex.
Research & References (3)
Randomized placebo-controlled, single blind trial of holy basil leaves in patients with noninsulin-dependent diabetes mellitus.
Randomized, placebo‑controlled, crossover, single‑blind trial in patients with non‑insulin‑dependent diabetes mellitus assessing holy basil leaf treatment versus placebo leaves.
In vivo enhancement of natural killer cell activity through tea fortified with Ayurvedic herbs.
Two double‑blind intervention studies compared a tea fortified with five Ayurvedic herbs (including Ocimum sanctum) with regular tea in older adults selected for low baseline NK cell activity.
Randomized placebo-controlled pilot clinical trial on the efficacy of ayurvedic treatment regime on COVID-19 positive patients.
Randomized, double‑blind, placebo‑controlled pilot trial of an Ayurvedic regimen for asymptomatic COVID‑19 that included Tulsi Ghanvati (0.5 g) among several other herbal/mineral components.
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Research Overview
Moderate EvidenceCite this ingredient
One-click citation export in APA, MLA, Chicago, BibTeX, or HTML. The URL below is stable and safe to link.
Stable URL
https://thesuppindex.com/ingredients/holy-basil
SuppIndex. (2026). Holy Basil: Evidence summary, dosage and clinical studies. Retrieved October 16, 2026, from https://thesuppindex.com/ingredients/holy-basil
Based on 3 indexed studies · Evidence level: Moderate.
Goal Ratings
Stack Compatibility
Appears commonly used in multi‑herb teas and Ayurvedic combinations; effects observed in combination trials cannot be attributed to holy basil alone.