Tulsi (Holy Basil) in Ayurveda: Traditional Use, Research and Safety

Tulsi is a plant that is part kitchen herb and part household shrine. In many Indian homes a tulsi plant stands in a courtyard pot or a raised platform, tended and circled each morning. Ayurveda also describes it in its materia medica, and holy basil tea has become a familiar drink far from India.

This page explains tulsi as the tradition sees it, what can honestly be said about modern research, and where our own safety information runs out. It is education about a traditional herb. It does not recommend tulsi for any health problem and gives no amounts for health.

What it is

Tulsi is a fragrant, bushy plant of the mint family, botanically Ocimum tenuiflorum (also written Ocimum sanctum). It is a different plant from the sweet basil used in Italian cooking, with a more peppery, clove-like scent.

• Sanskrit: tulasi (also surasa in some texts)
• Hindi: tulsi
• English: holy basil, sacred basil
• Plant part used: mainly the leaves; seeds, stems and roots also appear in traditional preparations

Several types are grown, often called green or Rama tulsi and dark or Krishna (Shyama) tulsi, and they differ in colour and in flavour. Tradition does not always draw a sharp line between them, and teachers differ on how they are used.

The traditional view

In standard Ayurvedic materia medica, the commonly taught profile of tulsi is as follows. As with many herbs, accounts vary a little between teachers and between regions.

• Taste (rasa): pungent (katu) and bitter (tikta)
• Energy (virya): heating (ushna)
• After-digestion effect (vipaka): pungent
• Effect on the doshas: said to calm kapha and vata and to increase pitta

You can read about how taste and energy shape the system on the six tastes page. The dosha pages explain the three principles named above, starting with kapha, which tulsi’s warming and drying qualities are traditionally said to answer.

The classical texts and later teachers speak of tulsi in connection with the breath, the throat and the chest, and with the changing seasons of damp weather. These are statements of tradition. We repeat them as part of the history of the plant, and they should not be read as claims that tulsi treats or prevents any illness.

Tulsi’s cultural role is larger than its medicinal reputation. It is a sacred plant in Hindu households, associated with the goddess Tulasi and with Vishnu worship, and leaves are used in offerings. Some families observe customs about when leaves may be picked. That religious setting is part of why tulsi is treasured, and it is worth remembering when comparing a home-grown plant with a commercial product.

In the kitchen and household

Tulsi is not a major cooking herb in the same way as cumin or coriander, but it has a few well-known food uses.

• A few fresh leaves steeped in hot water as a simple herbal infusion, often with ginger or a slice of lemon
• Leaves added to tea in the monsoon and winter months, an everyday habit in many homes
• Leaves dropped into the water kept for offerings, then shared
• Dried leaves blended into packaged herbal tea mixes

Fresh tulsi has a lively aroma that fades quickly when it is dried and stored, so many people prefer to grow a pot on a sunny window ledge. The plant dislikes cold and enjoys regular pinching back, which also stops it going to flower too early. If you want a herb that connects to the seasons the way Ayurveda reads them, see the pages on the rainy season and the ritucharya overview.

Because tulsi is warming and pungent, those who tend to run hot or have a sour stomach might notice a cup of strong tulsi tea sits differently to a mild one. Tradition asks you to watch your own response rather than follow a rule.

What research says

No dedicated safety page for tulsi exists on NCCIH, LiverTox or MedlinePlus, which are the sources this site uses. That means we cannot summarise a body of reviewed evidence for it. What we can report is general: research in people is limited, mostly small trials, and much of what is cited online comes from laboratory or animal work. Those findings do not prove an effect in people.

The NCCIH page on Ayurvedic medicine also notes that research on Ayurvedic treatments in general is limited and that some trials are small and poorly designed. A long history of use is a fact about culture and tradition. It is not proof that something works or that it is safe in every situation.

Safety and interactions

This is a statement of what we could not confirm and not a statement that tulsi is safe or unsafe. None of the three sources we use has a dedicated page on it, so we do not claim a specific interaction or a specific safe amount. The general points below apply.

• Everyday food use: a leaf or two in ordinary cooking or a mild tea is the baseline most families know.
• Pregnancy and breastfeeding: safety has not been established, so supplement forms are best avoided unless a doctor agrees.
• Concentrated products: capsules, extracts and essential oils fall outside ordinary food use. Because no source we checked has covered them, please ask a doctor or pharmacist first.
• Children and babies: the same applies; ask a paediatrician before giving any herbal product.
• Before surgery or with medicines: this matters especially with blood thinners, diabetes medicines, thyroid medicines, blood pressure medicines, immunosuppressants and chemotherapy. Say so to your doctor and pharmacist, and tell every provider about all Ayurvedic products.
• Interactions in general: NCCIH says most herb-drug interactions listed in current sources are hypothetical, inferred from animal studies, cell experiments or indirect evidence, with care most needed for drugs with a narrow safety margin such as warfarin, digoxin and cancer chemotherapy. It does not name tulsi.
• Contamination: NCCIH notes some Ayurvedic preparations may contain lead, mercury or arsenic at toxic levels, and that a 2015 survey reported elevated blood lead in about 40 percent of users of such products. Buy from sources you can trust, and prefer your own plant for leaf use.

For a wider look at how we handle uncertain areas, see how we write and the main herbs section.

This page is education, not medical advice. Please read our medical disclaimer, see a doctor about any health concern, and a registered Ayurvedic practitioner (BAMS in India) for Ayurvedic treatment.

Frequently asked questions

Sources: No NCCIH, MedlinePlus or LiverTox page exists for this herb. General points are from NCCIH: Ayurvedic Medicine in Depth and NCCIH: Herb-Drug Interactions.