holy basil

Holy basil (also called tulsi; Ocimum sanctum, also written Ocimum tenuiflorum) is an aromatic plant in the mint family, native to the Indian subcontinent and related to culinary sweet basil. It has a long history of use in traditional Ayurvedic practice. In the US its leaves and extracts are sold as a dietary supplement in capsule, tablet, tincture, powder, and tea forms.

These are traditional and popular uses, not proven medical benefits. High-quality human evidence is limited: most studies have been small and short-term, and US-government health authorities do not publish a fact sheet summarizing holy basil's effectiveness. NCCIH's "Herbs at a Glance" fact-sheet series does not include holy basil/tulsi, and there is no dedicated NIH Office of Dietary Supplements or NCCIH effectiveness page for it. Holy basil should not be assumed to treat, cure, or prevent any disease.

There is no established standard or government-recommended dose for holy basil, and amounts vary widely between products and study protocols. Because dietary supplements are regulated less strictly than prescription or over-the-counter medicines and potency can differ between brands, talk to a doctor or pharmacist before starting holy basil, especially if you are pregnant, breastfeeding, have a health condition, or take any medication.

Holy basil is widely consumed as a food and as a tea, but its long-term safety as a concentrated supplement has not been well established in rigorous human studies. As a general principle, "natural" does not always mean safe. People who are pregnant or trying to conceive should be especially cautious, because some animal studies have raised questions about possible effects on fertility (these findings are from animals and have not been confirmed in well-designed human trials). Discuss use with a clinician before combining it with prescription drugs or before any surgery.

Reported effects are generally described as mild and may include nausea or stomach upset. Because holy basil might lower blood sugar in some people, there is a theoretical concern it could contribute to levels dropping too low, particularly in those already taking blood-sugar-lowering medication. As with any botanical, allergic reactions are possible; stop use and seek care if you notice signs of an allergic reaction.

Holy basil could theoretically add to the effect of medicines that lower blood sugar (such as diabetes drugs), so people taking those should be cautious and monitor as advised by their clinician. Some sources also raise a theoretical concern about additive effects with blood-thinning (anticoagulant or antiplatelet) medicines and around the time of surgery, though human evidence is limited. Review your full medication list with a pharmacist or doctor before use, and tell your surgical team about any supplements before a procedure.