Holy Basil (Tulsi, Kaphrao): The Sacred and the Stir-Fry Basil

The “holy basil” at the store might not be holy basil at all; the label sometimes ends up on Thai or sweet basil. The real thing, Ocimum tenuiflorum, is a separate species from the sweet basil of Italian cooking. In India it’s tulsi, a plant sacred in Hinduism and widely used in Ayurvedic medicine. In Thailand it’s kaphrao, the peppery basil that gives the stir-fry phat kaphrao its name, and it goes in at the very end.

At a glance

What holy basil is

Holy basil is a flowering plant of the mint family grown for its aromatic leaves, also called tulsi or tulasi. Kew’s Plants of the World Online accepts the name Ocimum tenuiflorum and gives its native range as tropical and subtropical Asia to the western Pacific.² The Herb Society of America describes it as native to the Indian subcontinent and spread through Southeast Asia.³

Holy basil vs. sweet and Thai basil

The basil of Italian cooking is Ocimum basilicum; the FDA’s list of spices names “sweet basil” as that species.⁴ Holy basil is a different species.

Mislabeling tends to go one way. Andy Ricker, in his Thai cookbook Pok Pok, warns that “holy basil” labels sometimes end up on purple-stemmed Thai or sweet basil, and notes that Indian grocers may sell true holy basil as tulsi.⁵ You’ll also read that most “holy basil” on the market is really Mediterranean basil. We didn’t find a survey that measures how common the mix-up is. See Thai basil vs. holy basil, holy basil vs. basil and our Thai basil profile.

Red and white holy basil

A Chiang Mai University study of five basils used as food in Thailand analyzed two holy basils: a red form (O. sanctum var. Shyama) and a white form (O. sanctum var. Rama). Trained panelists could tell their oils apart, mainly by how strong the anise-like note was.¹

Flavor and aroma

Ricker describes holy basil as having a peppery flavor and a distinctive aroma, and calls it “holy or hot basil”. The Herb Society of America calls its taste astringent and its aroma strong, and says it may not please everyone.³ A lot of cooks pick up a clove-like note, too. It’s less sweet than Italian basil.

The compounds

In the 2018 Thai study, both holy basils fell into a “spice-like” aroma group defined by methyl eugenol, β-caryophyllene and α-cubebene.¹

Source: Tangpao, Chung and Sommano, 2018; plants grown at a research center in Chiang Mai.¹ These are concentrations in the oil from one growing site, not percentages, so don’t compare them directly with percentage figures from other studies. The study also found that the oils of both holy basils gave the strongest woody scent of the five basils tested.

Tulsi in Hinduism

Holy basil is considered sacred in Hinduism, revered in the Vaishnava tradition, and it’s common for Hindu families to grow it at home. Other stories get passed around too: that holy basil is the incarnation of a goddess, that British colonial courts had witnesses swear on it, that it’s been used medicinally for 3,000 years, and that it’s been found growing wild in Greece. We couldn’t trace any of them to a source we could open, so we’re leaving them out.

How holy basil is used

• Thailand. Holy basil is the herb in phat kaphrao, the stir-fry named after it. Ricker adds it at the very end and stirs just until it wilts and turns very fragrant.⁵ Phat kaphrao, a stir-fry of meat or seafood with the leaves, is the best-known dish that uses it.
• India. It’s widely used in Ayurvedic and folk medicine, often as an herbal tea.
• Southeast Asia generally. It’s used as a culinary herb throughout the region.

Think of it as a cooking herb that goes in at the end, as in phat kaphrao, more than a raw garnish. If you can’t find it, see holy basil substitutes.

Buying and storage

Buy it by smell. It should be peppery, not sweet or anise-like. You’ll find true holy basil in Thai and Indian groceries, sometimes sold as tulsi. We didn’t find storage guidance specific to holy basil from any regulator or standards body; see how to store basil for general basil handling.

Health claims and safety

What the evidence shows

Tulsi is sold widely as a supplement and tea, and the claims about it run far ahead of the evidence. The NIH’s National Center for Complementary and Integrative Health has no fact sheet on holy basil.⁶

The main systematic review, by Jamshidi and Cohen (2017), found 24 human studies on metabolic disorders, cardiovascular disease, immunity and neurocognition. All reported favorable results and none reported significant adverse events; one study noted occasional nausea. But the authors judged only a minority of the studies to be high quality (their text gives both three and seven as the count), said the effects may have been overestimated, and found insufficient evidence for any specific tulsi formulation in any one condition. They called for more studies on dosage, mechanisms and who might benefit. One author disclosed paid work as a consultant to a company that sells tulsi products.⁷

We’re not claiming holy basil treats or prevents fever, respiratory illness, heart disease or any other condition. The vitamin and mineral claims often attached to it aren’t backed by any nutrient analysis we found.

Methyl eugenol

Methyl eugenol, the leading compound in the Thai holy basil oils above, is one of the alkenylbenzenes regulators have looked at. Germany’s Federal Institute for Risk Assessment (BfR) notes that these compounds, including methyl eugenol, showed mutagenic and carcinogenic properties in animal studies. EU rules don’t allow methyl eugenol to be added to food as a flavoring, and maximum levels apply in certain foods where it occurs naturally.⁸ The BfR’s overall conclusion in 2022 was that the health risk from alkenylbenzene-containing foods can’t yet be conclusively assessed.⁸ It doesn’t single out holy basil, and it doesn’t tell people to stop eating basil. Our basil profile covers the related estragole evidence.

Holy basil isn’t on the FDA’s list of spices generally recognized as safe, which names only sweet basil and bush basil among the basils.⁴ We don’t draw any safety conclusion from that absence.

Substitutes and comparisons

Thai basil is the most common stand-in, but its smell leans toward anise instead of holy basil’s pepper. See holy basil substitutes, holy basil vs. basil and Thai basil vs. holy basil.

Related pages

• Basil
• Thai basil
• Lemongrass
• Kaffir lime leaves