Holy Basil (Tulsi)
Ocimum sanctum / tenuiflorum
A sacred adaptogen with real glucose and stress data.
Evidence tier
Moderate
Research weight
Citations
14 verified / 14
Classification
Ayurvedic
❝
What the evidence says. Several controlled trials; effects real but modest or context-dependent.
What is Holy Basil (Tulsi)?
Holy Basil (Tulsi) (Ocimum sanctum / tenuiflorum) is an Ayurvedic herb used for lower fasting & post-meal blood glucose. NutriDex grades the human evidence as Moderate. Tulsi is revered in India and classed as an adaptogen. A meta-analysis of randomized trials found it lowers fasting and post-meal blood glucose and improves lipids in people with metabolic disease, and several RCTs show reduced stress, anxiety and cortisol. Trials are mostly small with variable extracts, but the consistency across metabolic and stress outcomes makes it one of the stronger Ayurvedic adaptogens.
Purported Benefits
✓Lower fasting & post-meal blood glucose
✓Reduced stress, anxiety & cortisol
✓Improved lipid profile
Evidence by outcome
The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.
| Outcome | Evidence | Effect | Studies |
|---|---|---|---|
| Lower fasting & post-meal blood glucoseMeta-analysis plus several RCTs are consistent, but trials are small with variable extracts. | Moderate | ↑ benefit · moderate | 4 |
| Reduced stress, anxiety & cortisolMultiple double-blind RCTs show reduced perceived stress and hair cortisol; samples are modest. | Moderate | ↑ benefit · moderate | 3 |
| Improved lipid profileMeta-analysis and RCTs improved LDL/TG/HDL in metabolic disease; some trials open-label. | Moderate | ↑ benefit · small | 3 |
| Improved cognition/reaction timeSingle 30-day placebo-controlled trial in healthy adults; needs replication. | Preliminary | ↑ benefit · small | 1 |
| Reduced gingival bleeding & plaqueOne triple-blind RCT found a mouthrinse equal to chlorhexidine; topical use, single study. | Preliminary | ↑ benefit · moderate | 1 |
Dosing & Compounds
Typical Dose
~300 mg/day of standardized extract (or brewed leaves).
Active Compounds
Safety & Cautions
Generally safe. May lower blood sugar (caution with diabetes drugs) and has antiplatelet effects (caution with anticoagulants). Animal data suggest possible anti-fertility effects — avoid when trying to conceive or in pregnancy. Educational only — always check with your doctor or pharmacist before combining Holy Basil (Tulsi) with any medicine.
Key Studies ★ 14 studies
systematic review
Human clinical systematic review (Jamshidi & Cohen 2017)
✓ Full text
Systematic review of 24 human studies found tulsi ingestion produced favorable clinical outcomes across metabolic, cardiovascular, immune, and neurocognitive endpoints with no significant adverse events reported, supporting use for stress and lifestyle-related chronic disease.
Systematic review
Jamshidi & Cohen, 2017 (Tulsi clinical systematic review)
✓ PubMed
Systematic review of 24 human studies (the only such review of tulsi clinical data) found consistently favourable outcomes across metabolic disorders, cardiovascular disease, immunity and neurocognition, with no significant adverse events reported; concluded tulsi is an effective adjunct for lifestyle-related chronic disease including diabetes, metabolic syndrome and psychological stress. Per PubMed (DOI 10.1155/2017/9217567).
Meta-analysis
Glucose/lipid meta-analysis
✓ Full text
Lowered fasting glucose and improved lipid profile in metabolic disease.
systematic review
Anticandidal systematic review
✓ PubMed
PRISMA systematic review of microbial studies found all included studies demonstrated effective anti-candidal activity of O. sanctum, attributed mainly to eugenol and linalool.
RCT
Lopresti et al., 2022 (Holixer RCT)
✓ PubMed
8-week, double-blind, placebo-controlled RCT (n=100) of Ocimum tenuiflorum extract 125 mg twice daily in stressed adults: vs placebo, greater reductions in Perceived Stress Scale (p=0.003) and Athens Insomnia Scale (p=0.025), lower hair cortisol at week 8 (p=0.025), and buffered acute-stress salivary cortisol/amylase and blood pressure responses (p<=0.025).
RCT
Satapathy et al. 2017
✓ Full text
Randomized open-label trial in 30 young overweight/obese subjects: 250 mg O. sanctum extract twice daily for 8 weeks significantly improved plasma insulin (p=0.021), insulin resistance (p=0.049), BMI, and lipids, with no change in liver enzymes.
RCT
Saxena et al., 2012 (OciBest stress RCT)
✓ PubMed
6-week, randomized, double-blind, placebo-controlled trial (n=150) of O. tenuiflorum extract (OciBest, 1200 mg actives/day) for general stress: significant reductions vs placebo in total symptom score and in forgetfulness, sexual problems, exhaustion and sleep problems (p<=0.05); ~39% greater improvement in stress symptoms than placebo; well tolerated with no adverse events. Per PubMed (DOI 10.1155/2012/894509).
Clinical trial
Holixer stress RCT
✓ Full text
Reduced stress, improved mood and sleep vs placebo.
Clinical trial
1996 diabetes RCT
✓ PubMed
Significant reductions in fasting and postprandial glucose.
RCT
Overweight/obese metabolic RCT
✓ PubMed
Open-label RCT in 30 overweight/obese adults (250 mg twice daily, 8 weeks) significantly improved triglycerides, LDL, HDL, BMI and insulin resistance with no change in liver enzymes (SGOT/SGPT).
randomized controlled trial
Gingivitis/plaque RCT vs chlorhexidine
✓ PubMed
Triple-blind RCT in 108 medical students found Ocimum sanctum mouthrinse significantly reduced gingival bleeding and plaque indices at 15 and 30 days, equivalent to chlorhexidine, without chlorhexidine's side effects.
randomized controlled trial
Cognition RCT in healthy adults
✓ PubMed
Placebo-controlled trial of 300 mg/day ethanolic holy basil leaf extract for 30 days significantly improved reaction time and error rate on Sternberg memory and Stroop tasks versus placebo, indicating cognition-enhancing potential.
review
2024 multi-activity review
✓ Full text
Comprehensive review concludes Ocimum sanctum enhances insulin secretion and pancreatic beta-cell activity (anti-diabetic) and shows broad-spectrum antibacterial and anti-carcinogenic activity, largely via eugenol.
review
Immunomodulator/ischemic stroke review
✓ PubMed
Review proposes O. sanctum as an immunomodulator for ischemic brain injury via antioxidant and anti-inflammatory modulation of innate and adaptive immune responses.