Plant Profile

Holy Basil

Compiled by the Omnia Sana editorial team from the plant database ·Last updated August 15, 2026

Ocimum tenuiflorum

Family: Lamiaceae · Parts used: Leaf · Also known as: Tulsi, Sacred basil

The complete database record: 2 documented constituents, 6 pharmacological actions, 12 traditional / indicated uses, with 16 cited sources.

Botanical Description

Aromatic annual or short-lived perennial subshrub (Lamiaceae), 30-75 cm tall, with erect, much-branched, hairy stems often tinged purple. Leaves are opposite, ovate-oblong with a toothed margin, and release a strong, clove-like (eugenol) scent when crushed. Small purplish-pink, two-lipped flowers are borne in elongated terminal racemes. The plant is held sacred in Hindu tradition (Tulsi).^[11]

Height: 30-75 cm

Habit: Erect, much-branched, aromatic subshrub

Leaves: Opposite, ovate-oblong, toothed, clove-scented when crushed

Flowers: Small, purplish-pink, two-lipped, in elongated terminal racemes

Stem: Erect, much-branched, hairy, often purple-tinged

Root: Fibrous root system

Fruit: Four small nutlets (typical Lamiaceae schizocarp)

Flowering Period: Most of the year in tropical climates

Habitat & Distribution

Native to the Indian subcontinent and tropical Asia, now cultivated and naturalised throughout the tropics and subtropics worldwide; commonly grown in home gardens and temple courtyards as well as cultivated as a medicinal and aromatic crop.^[12]

Harvesting

Leaves are harvested year-round from actively growing plants, ideally picked once morning dew has dried; whole flowering tops are also gathered.

Parts: Leaf, Flowering tops

Season: Year-round in warm climates

Key Constituents

Volatile oil rich in eugenol^[11]

The principal aromatic constituent, with anti-inflammatory and antimicrobial activity.

Essential (volatile) oilEugenol

Ursolic acid, rosmarinic acid, apigenin and luteolin^[11]

Antioxidant and adaptogenic constituents.

Rosmarinic acidApigeninLuteolin

Pharmacological Actions

Adaptogen^{[1, 3, 12]}

Adaptogen for stress and anxiety (improves stress scores and well-being in trials)

Anti-inflammatory^{[3, 5, 11]}

Antioxidant and anti-inflammatory

Anticancer (preclinical)^{[2, 4, 10, 11]}

Antioxidant^{[3, 4, 5, 8, 11]}

Antioxidant and anti-inflammatory

Immunomodulator / immune support^{[3, 5, 9, 11, 12]}

Immunomodulatory / immune support

Neuroprotective / cognition support^[15]

Cognitive support - a placebo-controlled study in healthy adults found improved reaction time and accuracy and shorter P300 latency

Traditional & Indicated Uses

Anxiety^{[1, 12]}Good · 8/10

Adaptogen for stress and anxiety (improves stress scores and well-being in trials)

Evidence: 8

Label: Anxiety

more plants for anxiety →detailed sources →

Arthritis / joint pain

inferred from anti-inflammatory action

Mechanistic Exclude Ids: REF-0467

Evidence: 1

Label: Arthritis / joint pain

more plants for arthritis / joint pain →detailed sources →

Blood sugar / diabetes support^{[4, 12]}Good · 7/10

Supports blood-sugar control (lowers fasting and post-meal glucose)

Evidence: 7

Label: Blood sugar / diabetes support

more plants for blood sugar / diabetes support →detailed sources →

Cancer (anticancer research)^{[2, 4, 10, 11]}Good · 8/10

inferred from anticancer action

Evidence: 8

Label: Cancer (anticancer research)

more plants for cancer (anticancer research) →detailed sources →

Cognitive function^[15]Moderate · 5/10

inferred from neuroprotective action

Evidence: 5

Label: Cognitive function

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Cold & flu^[12]Good · 7/10

inferred from immunomodulator action

Mechanistic Exclude Ids: REF-0467, REF-1435

Evidence: 7

Label: Cold & flu

more plants for cold & flu →detailed sources →

Fatigue / low energy^[12]Good · 7/10

inferred from adaptogen action

Evidence: 7

Label: Fatigue / low energy

more plants for fatigue / low energy →detailed sources →

Immune support^[12]Good · 7/10

Immunomodulatory / immune support

Mechanistic Exclude Ids: REF-0467

Evidence: 7

Label: Immune support

more plants for immune support →detailed sources →

Inflammation (general)

inferred from anti-inflammatory action

Mechanistic Exclude Ids: REF-0467

Evidence: 1

Label: Inflammation (general)

more plants for inflammation (general) →detailed sources →

Memory^[15]Moderate · 5/10

inferred from neuroprotective action

Evidence: 5

Label: Memory

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Skin irritation

inferred from anti-inflammatory action

Mechanistic Exclude Ids: REF-0467

Evidence: 1

Label: Skin irritation

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Stress^{[1, 12]}Good · 8/10

Adaptogen for stress and anxiety (improves stress scores and well-being in trials)

Evidence: 8

Label: Stress

more plants for stress →detailed sources →

Traditional Use & History

Tulsi is one of the most revered plants in Ayurvedic medicine, traditionally used as an adaptogen for stress, a remedy for respiratory complaints (colds, cough, asthma), and a general immune tonic. Modern clinical trials support adaptogenic/anti-stress, blood-sugar-lowering and immunomodulatory effects consistent with these traditional uses.^{[3, 12]}

Preparations

Infusion (tea)^[3]

Dried or fresh leaf steeped in hot water, alone or blended with other herbs/spices.

Standardised extract capsule^{[1, 12]}

Encapsulated dry-leaf extract, the form used in most clinical trials for stress, mood and sleep.

Dosage

Standardised extract^{[1, 12]}

Clinical trials for stress and mood have used standardised dry-extract capsules taken over several weeks; dosing varies by product concentration, so follow the manufacturer's guidance. Educational reference only, not a prescription.

Infusion (tea)^[14]

The WHO monograph on Folium Ocimi Sancti gives a daily dosage of 6-12 g of the crude drug as a decoction. This is a whole-day total for the fresh or dried leaf, notably higher than the 1-2 g per cup often quoted in popular sources. Educational reference only, not a prescription.

Safety, Cautions & Contraindications

Safety note^[12]Caution

Generally well tolerated; mild nausea has been reported. Its blood-sugar-lowering effect means caution alongside antidiabetic medicines.

Safety note^{[11, 12]}Caution

Animal studies suggest mild anti-fertility and antiplatelet effects, so avoid medicinal doses when pregnant or trying to conceive, and before surgery.

Herb-Drug Interactions

Antidiabetics^{[12, 16]}Caution

Mechanism: Holy basil (tulsi) can lower fasting and after-meal blood glucose in people with type 2 diabetes; combined with diabetes medicines it may add to blood-sugar lowering, so monitor blood sugar.

Reviewed By: Omnia Sana (owner-authorized)

Reviewed Date: 2026-07-03

Harvest Readiness

^[13]

Part: leaf

Signals: Pick the leaves through the growing season (repeatedly, every couple of weeks); ideally before or as it comes into flower, when the aromatic oil is highest.

Basis: traditional

Source Quote: The leaves can be harvested during the growing season and used fresh or dried for later use.

Species Confirmed: 1

Notes: PFAF (REF-3300); the leaves are picked repeatedly during the growing season (twigs cut every ~2 weeks). Single lineage -> provisional.

External Identifiers

GBIF ›Wikidata ›

References & Sources

Lopresti, A.L., Smith, S.J., Metse, A.P. and Drummond, P.D (2022) 'A randomized, double-blind, placebo-controlled trial investigating the effects of an Ocimum tenuiflorum (Holy Basil) extract (Holixer) on stress, mood, and sleep in adults experiencing stress', Frontiers in Nutrition, 9, pp. 965130. doi:10.3389/fnut.2022.965130 Randomized trial
https://doi.org/10.3389/fnut.2022.965130
Baliga, M.S., Jimmy, R., Thilakchand, K.R., Sunitha, V. and others (2013) 'Ocimum sanctum L (Holy Basil or Tulsi) and its phytochemicals in the prevention and treatment of cancer', Nutrition and Cancer, 65(Suppl 1), pp. 26-35. doi:10.1080/01635581.2013.785010 Meta-analysis / review
https://doi.org/10.1080/01635581.2013.785010
Cohen, M.M (2014) 'Tulsi - Ocimum sanctum: A herb for all reasons', Journal of Ayurveda and Integrative Medicine, 5(4), pp. 251-259. doi:10.4103/0975-9476.146554 Meta-analysis / review
https://doi.org/10.4103/0975-9476.146554
Arya, R., Faruquee, H.M., Shakya, H., Rahman, S.A. and others (2024) 'Harnessing the Antibacterial, Anti-Diabetic and Anti-Carcinogenic Properties of Ocimum tenuiflorum Linn (Tulsi)', Plants, 13(24), pp. 3516. doi:10.3390/plants13243516 Preclinical
https://doi.org/10.3390/plants13243516
Prakash, P. and Gupta, N (2005) 'Therapeutic uses of Ocimum sanctum Linn (Tulsi) with a note on eugenol and its pharmacological actions: a short review', Indian Journal of Physiology and Pharmacology, 49(2), pp. 125-131. Meta-analysis / review
https://scholar.google.com/scholar?q=Therapeutic%20uses%20of%20Ocimum%20sanctum%20Linn%20%28Tulsi%29%20with%20a%20note%20on%20eugenol%20and%20its%20pharmacological%20actions%3A%20a%20short%20review
Jayapal, V., Vidya Raj, C.K., Muthaiah, M., Chadha, V.K. and others (2021) 'In-vitro anti-Mycobacterium tuberculosis effect of essential oil of Ocimum sanctum L. (Tulsi/Basil) leaves', Indian Journal of Tuberculosis, 68(4), pp. 470-473. doi:10.1016/j.ijtb.2021.02.009 Preclinical
https://doi.org/10.1016/j.ijtb.2021.02.009
Baliga, M.S., Rao, S., Rai, M.P. and D'souza, P (2016) 'Radio protective effects of the Ayurvedic medicinal plant Ocimum sanctum Linn. (Holy Basil): A memoir', Journal of Cancer Research and Therapeutics, 12(1), pp. 20-27. doi:10.4103/0973-1482.151422 Meta-analysis / review
https://doi.org/10.4103/0973-1482.151422
Kamel, F.O., Karim, S., Bafail, D.A.O., Aldawsari, H.M. and others (2023) 'Hepatoprotective effects of bioactive compounds from traditional herb Tulsi (Ocimum sanctum Linn) against galactosamine-induced hepatotoxicity in rats', Frontiers in Pharmacology, 14, pp. 1213052. doi:10.3389/fphar.2023.1213052 Preclinical
https://doi.org/10.3389/fphar.2023.1213052
Yadav, I., Kumar, R., Fatima, Z. and Rema, V (2024) 'Ocimum sanctum (Tulsi) as a Potential Immunomodulator for the Treatment of Ischemic Injury in the Brain', Current Molecular Medicine, 24(1), pp. 60-73. doi:10.2174/1566524023666221212155340 Meta-analysis / review
https://doi.org/10.2174/1566524023666221212155340
Kumar, P. and Patel, D (2023) 'Ocimum Sanctum: An All-Round Treatment for Cancer?', Alternative Therapies in Health and Medicine, 29(4), pp. 253-257. Meta-analysis / review
https://scholar.google.com/scholar?q=Ocimum%20Sanctum%3A%20An%20All-Round%20Treatment%20for%20Cancer%3F
Bhattacharyya, P. and Bishayee, A (2013) 'Ocimum sanctum Linn. (Tulsi): an ethnomedicinal plant for the prevention and treatment of cancer', Anti-Cancer Drugs. doi:10.1097/CAD.0b013e328361aca1 Traditional / reference
https://doi.org/10.1097/CAD.0b013e328361aca1
Jamshidi, N. and Cohen, M.M (2017) 'The Clinical Efficacy and Safety of Tulsi in Humans: A Systematic Review of the Literature', Evidence-Based Complementary and Alternative Medicine. doi:10.1155/2017/9217567 Meta-analysis / review
https://doi.org/10.1155/2017/9217567
Plants For A Future 'Ocimum tenuiflorum (Holy Basil, Tulsi)'. Available at: https://pfaf.org/user/Plant.aspx?LatinName=Ocimum+tenuiflorum Traditional / reference
https://pfaf.org/user/Plant.aspx?LatinName=Ocimum+tenuiflorum
World Health Organization (2002) 'Folium Ocimi Sancti'. Available at: https://iris.who.int/items/6418d8af-5200-4e6b-9bf5-004f3aa62a37 Traditional / reference
https://iris.who.int/items/6418d8af-5200-4e6b-9bf5-004f3aa62a37
Sampath, S., Mahapatra, S.C., Padhi, M.M., Sharma, R. and Talwar, A (2015) 'Holy basil (Ocimum sanctum Linn.) leaf extract enhances specific cognitive parameters in healthy adult volunteers: A placebo controlled study', Indian Journal of Physiology and Pharmacology, 59(1), pp. 69--77. Randomized trial
https://scholar.google.com/scholar?q=Holy%20basil%20%28Ocimum%20sanctum%20Linn.%29%20leaf%20extract%20enhances%20specific%20cognitive%20parameters%20in%20healthy%20adult%20volunteers%3A%20A%20placebo%20controlled%20study
Agrawal, P., Rai, V. and Singh, R.B (1996) 'Randomized placebo-controlled, single blind trial of holy basil leaves in patients with noninsulin-dependent diabetes mellitus', International Journal of Clinical Pharmacology and Therapeutics, 34(9), pp. 406-409. Randomized trial
https://scholar.google.com/scholar?q=Randomized%20placebo-controlled%2C%20single%20blind%20trial%20of%20holy%20basil%20leaves%20in%20patients%20with%20noninsulin-dependent%20diabetes%20mellitus

Selected studies & references

ReviewOcimum sanctum (Tulsi) as a Potential Immunomodulator for the Treatment of Ischemic Injury in the Brain source↗ (2024)

ReviewOcimum Sanctum: An All-Round Treatment for Cancer? source↗ (2023)

ReviewThe Clinical Efficacy and Safety of Tulsi in Humans: A Systematic Review of the Literature source↗ (2017)

ReviewRadio protective effects of the Ayurvedic medicinal plant Ocimum sanctum Linn. (Holy Basil): A memoir source↗ (2016)

ReviewTulsi - Ocimum sanctum: A herb for all reasons source↗ (2014)

ReviewOcimum sanctum L (Holy Basil or Tulsi) and its phytochemicals in the prevention and treatment of cancer source↗ (2013)

ReviewTherapeutic uses of Ocimum sanctum Linn (Tulsi) with a note on eugenol and its pharmacological actions: a short review source↗ (2005)

RctA randomized, double-blind, placebo-controlled trial investigating the effects of an Ocimum tenuiflorum (Holy Basil) extract (Holixer) on stress, mood, and sleep in adults experiencing stress source↗ (2022)

All 14 studies in the Knowledge Finder →

Educational use only. This profile summarises traditional and scientific sources for reference. It is not medical advice and not a substitute for a qualified practitioner. Some plants carry safety cautions and drug interactions - always check before use.
This profile is assembled automatically from the Omnia Sana plant database, which we curate by hand. How this site is built.

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