Holy basil, tulsi (Ocimum sanctum, Ocimum tenuiflorum)

Holy basil (tulsi) is an Ayurvedic herb whose supplement extracts are promoted to strengthen immunity and prevent colds and flu. There is no convincing evidence that tulsi lowers how often people catch respiratory infections or how severe they get; the available studies are few and of low quality. A common cold gets better with rest, fluids and time, vaccination protects against flu, and a doctor may prescribe antivirals for people at higher risk. At usual doses tulsi is well tolerated, but its benefit for immunity has not been confirmed

Tulsi (holy basil) is sold as an «Ayurvedic adaptogen» against stress and anxiety. Evidence base is weak: several small Indian RCTs showed heterogeneous results on stress scales; no large international RCTs. EFSA 2010 approved no health claim for tulsi. NICE 2022 and SEP 2014 list SSRIs and CBT for anxiety disorders; tulsi is in no international guideline. If tulsi was recommended for clinically significant anxiety instead of psychotherapy and an antidepressant, consider seeking a second opinion. Important: high-dose tulsi extracts have caused isolated drug-induced liver injury cases.

Holy basil, or tulsi (Ocimum sanctum), is a plant from Ayurveda sold as a supplement to lower blood sugar in type 2 diabetes. Studies have not shown a convincing benefit for this use, and the evidence base for taking tulsi in type 2 diabetes is lacking. Blood sugar drops reliably with changes to diet, physical activity, weight loss and medications of proven effectiveness that a doctor selects.