Holy Basil (Tulsi)

Ocimum sanctum · Ocimum tenuiflorum · Tulsi · Holy Basil

Snapshot

Indications	Contraindications
Perceived stress¹ Stress-related sleep complaints² Anxiety³ Cognitive performance³ Glycemic control⁴ Dental plaque and gingivitis⁵ Halitosis⁶	Pregnancy⁷

Holy basil (Ocimum tenuiflorum, also Ocimum sanctum; tulsi) is an aromatic herb of Ayurveda³. Its anti-stress action is attributed to blunting cortisol signaling along the hypothalamic-pituitary-adrenal (HPA) axis³. People take it for perceived stress and the sleep complaints that accompany it^{1, 2}. Other uses are anxiety and cognition, where small studies exist³, glycemic support, and oral hygiene as a mouth rinse.

In placebo-controlled trials of standardized extracts, stress scores and stress-related symptoms improved, and tolerability was good^{1, 2}. A systematic review found that the effect of most plant ingredients on HPA-axis hormones in humans remains unclear⁸. As a mouth rinse, it matched chlorhexidine for plaque and gingivitis in one trial and fell short of it in another. In human kidney cell cultures, a 2026 study found tulsi leaf extract reduced oxidative injury; no human trial has tested this. Products come as capsules, liquid extracts, and tablets, with over a thousand products listing holy basil; see Form comparison.

Last updated October 15, 2026. Read how we make monographs.

In the full monograph

48 sources, 36 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources