Last verified: today
Holy Basil
Also known as: Ocimum sanctum, Tulsi, Sacred Basil, Ocimum tenuiflorum
Evidence under review. — Not yet rated
Adaptogenic herb with early evidence for stress relief, cognition, and blood sugar support.
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What it does
Holy Basil (Ocimum sanctum), also called Tulsi, is a traditional Ayurvedic herb used as an adaptogen — meaning it may help the body cope with stress. Early clinical trials suggest it can reduce...
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Evidence quality
Evidence base hasn't been formally rated yet. See research below.
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Clinical dose
300 mg/day (leaf extract) based on available clinical data
What the Science Says
Holy Basil (Ocimum sanctum), also called Tulsi, is a traditional Ayurvedic herb used as an adaptogen — meaning it may help the body cope with stress. Early clinical trials suggest it can reduce perceived stress, improve reaction time and cognitive performance, and modestly lower fasting blood glucose in people with mild type 2 diabetes. Most human studies are small and short-term, so results should be interpreted cautiously.
What It Doesn't Do
Not a proven cancer treatment — lab studies on cancer cells don't translate to humans. Won't replace diabetes medication. No solid evidence it works as a mosquito repellent in humans. The anti-aging skin cream research is about a blend of oils, not Holy Basil alone. Don't expect dramatic cognitive transformation from a single ingredient.
Evidence-Based Benefits
May reduce perceived stress and anxiety scores in adults with high stress levels.
Weak EvidenceEffective at: No established solo dose — used in multi-herb formula in clinical trial
300 mg/day of leaf extract improved reaction time and reduced errors on cognitive tests in healthy adults.
Weak EvidenceEffective at: 300 mg/day
Holy basil leaves reduced fasting blood glucose by ~17% in people with mild type 2 diabetes.
Weak EvidenceEffective at: Whole leaf form; exact dose not specified in study
A multi-herb formula containing Holy Basil improved sleep quality scores compared to placebo.
Weak EvidenceEffective at: No established solo dose — used in multi-herb formula
Absorption & Bioavailability
Unknown — no pharmacokinetic studies were provided. One lab study explored nanoemulsion formulations to improve bioavailability of its compounds, suggesting standard oral absorption may be limited.
Red Flags to Watch For
- Most clinical trials are small (single studies, not replicated) and short-term — long-term safety data is limited
- The stress-reduction study used Holy Basil in a multi-herb blend (with Rhodiola and Schisandra), making it impossible to isolate Holy Basil's individual contribution
- Blood sugar lowering effect could interact with diabetes medications — consult a doctor before use
- No standardized dosing exists across products — 1,000+ registered supplements vary widely in extract type and potency
Products Containing Holy Basil
See how Holy Basil is used in these analyzed products:
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-05-25