Outcome
    Moderate Evidence

    Holy Basil (Tulsi) for Immune Function

    Immune claims rest on small biomarker studies rather than infection outcomes.

    Overview

    Immune claims rest on small biomarker studies rather than infection outcomes.

    Verdict

    Insufficient evidence

    How It Works

    Tulsi extracts modulate cytokine production and T-helper cell activity in laboratory and animal models.

    Dosing & Protocol

    Typical dose

    Recommended dose
    Not established; the one relevant trial used 300 mg/day of extract and measured immune cell markers, not infection outcomes
    Expected timeframe
    Not established

    Protocol

    form
    Not applicable
    duration
    Not applicable
    co factor
    Evidence is insufficient. Holy basil has immunomodulatory activity in laboratory and animal studies, and one small randomised trial in healthy volunteers found that 300 mg/day of ethanolic leaf extract for four weeks increased interferon-gamma, interleukin-4 and T-helper and natural killer cell percentages compared with placebo. That is a single small study measuring immune cell markers, not clinical outcomes: no trial has shown holy basil reduces the frequency, duration or severity of infections. Changes in circulating immune cell counts are notoriously poor predictors of resistance to infection, and the traditional Ayurvedic use, while long-standing, is not evidence of efficacy.
    titration
    Not applicable
    starting dose
    Not applicable as an established treatment

    Evidence

    What the studies say

    One small trial in healthy volunteers reported increased interferon-gamma and NK-cell activity after four weeks. No trials measure clinical infection rates.

    No studies are yet linked to both Holy Basil (Tulsi) and Immune Function.

    Safety

    Caveats

    Recurrent, severe or unusual infections need medical investigation rather than immune supplements - underlying immunodeficiency, diabetes, HIV and haematological conditions are identifiable. What genuinely reduces infection risk is vaccination, sleep, hand hygiene and treating underlying conditions. Safety: holy basil lowers blood glucose, so it can cause hypoglycaemia with insulin or sulfonylureas. It has antiplatelet activity and may increase bleeding risk with warfarin, DOACs, aspirin and clopidogrel - stop two weeks before surgery. Animal studies suggest possible antifertility and anti-spermatogenic effects with prolonged high doses, and it may have uterine-stimulant activity - avoid in pregnancy, when trying to conceive, and while breastfeeding. It may add to the effects of pentobarbital and other sedatives. There is no established upper intake level and limited long-term human safety data. Anyone on immunosuppressants should avoid immunomodulatory herbs without specialist advice.

    Less likely to help if

    Everyone: no infection outcome has been measured in any trial.

    Medical Disclaimer

    The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.

    Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.