This product is not intended to diagnose, treat, cure, or prevent any disease. These statements have not been evaluated by the Food and Drug Administration.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider before using herbs, especially if you are pregnant, nursing, taking medications, or have a medical condition.
This herb is NOT recommended during pregnancy due to potential risks to the developing fetus.
This herb is NOT recommended while breastfeeding as effects on infants are unknown.
Consult your healthcare provider before use.
2 Known Drug Interactions — Some May Be Serious
2 Moderate
This herb may interact with medications you are taking. Review the interactions table below and consult your healthcare provider before use.
What is a herb–drug interaction?
A herb–drug interaction happens when a plant or supplement changes how a medication works in your body — making it stronger, weaker, or more likely to cause harm. Herbs contain active compounds that can speed up or slow down the enzymes and transporters your body uses to process drugs.
Why it matters
•St. John's Wort can make birth control, antidepressants, and blood thinners less effective.
•Garlic can increase bleeding risk with warfarin and other blood thinners (also ginkgo, ginger, and turmeric).
•Kava can amplify sedation when taken with anxiety or sleep medications (also valerian).
The risk is highest for older adults, anyone taking several medications, and people with chronic conditions.
Always tell your doctor and pharmacist about every herb and supplement you take — and check below before combining.
Holy basil may have antiplatelet effects that increase bleeding risk with anticoagulant medications.
This list reflects a curated subset of documented interactions and is not exhaustive. The absence of a drug here is not proof that it is safe to combine. Always confirm with a pharmacist or healthcare provider.
How does holy basil work as an adaptogen in the body?
Holy basil contains bioactive compounds called ocimumosides and ursolic acid that help modulate the body's stress response system. These compounds appear to regulate cortisol levels and support healthy function of the hypothalamic-pituitary-adrenal (HPA) axis. Research indicates holy basil also reduces oxidative stress through antioxidant compounds like rosmarinic acid and eugenol. Evidence level B supports its adaptogenic properties, helping the body maintain homeostasis during physical and emotional stress. This mechanism distinguishes holy basil from common culinary basil varieties.
Does holy basil interact with blood thinners or other medications?
Holy basil may interact with anticoagulant and antiplatelet medications due to its mild blood-thinning properties. Combining holy basil with warfarin, aspirin, clopidogrel, or similar blood thinners could increase bleeding risk and should be avoided. Additionally, holy basil may affect thyroid function and could interfere with thyroid medications like levothyroxine. Those taking diabetes medications should monitor blood sugar closely, as holy basil may enhance glucose-lowering effects. Always consult a healthcare provider before combining holy basil with prescription medications.
What is the recommended dosage for holy basil supplements?
The standard adult dosage for holy basil is 300-600mg of standardized extract daily, or 2-3 cups of fresh leaf tea per day. For stress and anxiety support, practitioners often recommend dividing doses throughout the day. Standardized extracts typically contain marker compounds such as ursolic acid or eugenol at specified concentrations. Traditional Ayurvedic use involves chewing 4-12 fresh leaves daily. Start with lower doses and gradually increase to assess individual tolerance and response.
Is holy basil safe to take during pregnancy or breastfeeding?
Holy basil is considered unsafe during pregnancy and should be avoided. Traditional use and animal studies suggest holy basil may have anti-fertility effects and could stimulate uterine contractions, potentially increasing miscarriage risk. Limited safety data exists for breastfeeding, so avoidance is recommended for nursing mothers. Women trying to conceive should also exercise caution, as holy basil may affect fertility. Consult a qualified healthcare provider for personalized guidance on herbal use during pregnancy or while breastfeeding.
What are the main health benefits of holy basil (Tulsi)?
Holy basil is traditionally used for stress relief, respiratory health, digestive support, and immune function. Evidence level B supports its use as an adaptogen for managing stress and anxiety symptoms. The herb contains eugenol and rosmarinic acid, which provide anti-inflammatory and antioxidant benefits. Ayurvedic medicine classifies Tulsi as a rasayana (rejuvenating herb) for promoting longevity and vitality. It may also support healthy blood sugar levels and cardiovascular function. Three varieties exist: Rama, Krishna, and Vana, each with traditional applications.
Can holy basil cause side effects or adverse reactions?
Holy basil is generally well-tolerated, but some individuals may experience gastrointestinal upset, nausea, or mild headache. Due to its blood-thinning properties, holy basil may increase bleeding risk, particularly in those with bleeding disorders. Some evidence suggests potential anti-fertility effects with long-term high-dose use. Discontinue use at least two weeks before scheduled surgery to reduce bleeding complications. Those with hypothyroidism should use caution, as holy basil may affect thyroid function. Evidence level B supports these safety considerations.
PubMed-compiled information sheet
This sheet was compiled from PubMed (NIH) abstracts using AI assistance. Every factual claim is cited to a real PubMed article (see the source list). It has not yet been human-reviewed — confirm with a healthcare provider before use.
Compiled from 30 PubMed articles · model: glm-5.2
Summary
Holy Basil (Ocimum tenuiflorum, synonym O. sanctum), also known as Tulsi, is a medicinal herb revered in Ayurveda with demonstrated adaptogenic, antimicrobial, anti-inflammatory, anticancer, and immunomodulatory properties supported by preclinical and limited clinical evidence [PMID:25624701, PMID:28400848].
Background
Ocimum tenuiflorum, commonly known as Holy Basil or Tulsi, is a fragrant herbaceous plant belonging to the Lamiaceae family, indigenous to the Indian continent and widely cultivated in India, several Arab countries, West Africa, and tropical regions of the Eastern World [PMID:39771214, PMID:28400848, PMID:36200220]. It is revered in Ayurveda as the 'Elixir of Life' and is believed to promote longevity and general wellbeing [PMID:36185698, PMID:39771214]. Tulsi is preeminent among Ayurvedic herbs and has been utilized since ancient times in the management of a large number of diseases [PMID:25624701, PMID:37567911].
Traditional uses
In traditional systems of medicine including Ayurveda, Unani, and Siddha, different parts of O. sanctum (leaves, stem, flower, root, seeds, and whole plant) have been recommended for the treatment of bronchitis, bronchial asthma, malaria, diarrhea, dysentery, skin diseases, arthritis, painful eye diseases, chronic fever, and insect bite [PMID:16170979]. Tulsi has also been traditionally used in Ayurveda for menstrual irregularities, polycystic ovary syndrome (PCOS), infertility, and menopausal symptoms [PMID:38558676]. It has been used as a functional food ingredient in bakery products, dairy products, and beverages such as tea [PMID:38351693].
Active compounds
Key phytochemicals identified in Holy Basil include eugenol (1-hydroxy-2-methoxy-4-allylbenzene), rosmarinic acid, apigenin, myretenal, luteolin, β-sitosterol, carnosic acid, oleanolic acid, ursolic acid, limonene, camphor, eucalyptol, alpha-bisabolene, beta-bisabolene, beta-caryophyllene, orintin, and vicenin [PMID:23682780, PMID:39473808, PMID:36770859, PMID:16170979]. The plant is also rich in polyphenols, flavonoids, essential oils, and triterpenoids [PMID:40944265, PMID:35578854]. Eugenol is considered the active constituent largely responsible for the therapeutic potentials of Tulsi [PMID:16170979].
Mechanism of action
Tulsi acts as an adaptogen, aiding the body in adapting to stress by harmonizing various bodily systems [PMID:39771214]. Its phytochemicals mediate anticancer effects by increasing antioxidant activity, altering gene expressions, inducing apoptosis, and inhibiting angiogenesis and metastasis [PMID:23682780]. Polyphenols present in O. sanctum activate apoptotic signaling, cause cell cycle arrest, bind with membrane receptors, and affect immunomodulation and epigenetic mechanisms [PMID:35578854]. Eugenol exhibits antioxidant, antimicrobial, anesthetic, anti-inflammatory, neuroprotective, anti-diabetic, and anti-cancer activities [PMID:34218781]. Tulsi has been shown to protect organs and tissues against chemical stress from industrial pollutants and heavy metals, physical stress from prolonged physical exertion, ischemia, physical restraint, and exposure to cold and excessive noise, and to counter metabolic stress through normalization of blood glucose, blood pressure, and lipid levels [PMID:25624701].
Clinical evidence
Evidence BStress, mood, and sleep
An 8-week randomized, double-blind, placebo-controlled trial (n=100) found that 125 mg of a standardized Ocimum tenuiflorum extract (Holixer™) twice daily improved subjective and objective measures of stress and sleep quality in adults experiencing stress, including Perceived Stress Scale, Profile of Mood States, Athens Insomnia Scale, and Restorative Sleep Questionnaire outcomes [PMID:36185698].
Evidence AHPA axis modulation
A systematic review of randomized controlled human trials assessed the effects of single plants or phytonutrients on HPA-axis related hormones, identifying 52 studies examining effects on cortisol, cortisone, corticotrophin-releasing hormone, or adrenocorticotropic hormone [PMID:33650944].
Evidence AMetabolic disorders, cardiovascular disease, immunity, and neurocognition
A systematic review of human studies identified 24 studies reporting therapeutic effects of tulsi on metabolic disorders, cardiovascular disease, immunity, and neurocognition, with all studies reporting favourable clinical outcomes [PMID:28400848].
Evidence CCancer prevention and treatment
Multiple reviews report that Tulsi and its phytochemicals (eugenol, rosmarinic acid, apigenin, luteolin, β-sitosterol, carnosic acid) prevented chemical-induced skin, liver, oral, and lung cancers in preclinical studies through antioxidant activity, altered gene expressions, apoptosis induction, and inhibition of angiogenesis and metastasis [PMID:23682780, PMID:23629478, PMID:34331753, PMID:35578854, PMID:36770859].
Safety & adverse effects
A systematic review of human studies on tulsi's clinical efficacy and safety identified 24 studies reporting favourable clinical outcomes, though specific adverse event details from the review abstract are limited [PMID:28400848]. Reviews note that O. sanctum has been suggested to possess antifertility effects among its various pharmacological actions [PMID:16170979]. One review on cancer treatment noted that Ocimum sanctum may be helpful to many patients with few to no adverse events [PMID:34331753].
Pregnancy & lactation
O. sanctum has been suggested to possess antifertility properties based on traditional and pharmacological reports [PMID:16170979]. No specific data on safety during lactation are available from the provided abstracts.
Dosage & administration
In a randomized controlled trial, 125 mg of a standardized Ocimum tenuiflorum extract (Holixer™) was administered twice daily for 8 weeks to adults experiencing stress [PMID:36185698]. No other specific dosage data available from the provided abstracts. Consult a healthcare provider.
Evidence summary
The evidence base for Holy Basil includes two systematic reviews (one of 24 human clinical studies showing favourable outcomes across metabolic disorders, cardiovascular disease, immunity, and neurocognition; one on HPA axis modulation across 52 studies), one randomized double-blind placebo-controlled trial on stress and sleep, and numerous narrative reviews supporting preclinical pharmacological activities including anticancer, antimicrobial, neuroprotective, and radioprotective effects. Overall, clinical evidence is emerging but remains limited, with most pharmacological support derived from preclinical (in vitro and in vivo) studies and traditional use. Higher-quality randomized controlled trials with larger sample sizes are needed to confirm efficacy across indications.
PubMed sources
1.PMID: 38558676 (2024) — Ayurvedic Herbal Medicines: A Literature Review of Their Applications in Female Reproductive Health. · Cureus
2.PMID: 36185698 (2022) — A randomized, double-blind, placebo-controlled trial investigating the effects of an Ocimum tenuiflorum (Holy Basil) extract (HolixerTM) on stress, mood, and sleep in adults experiencing stress. · Frontiers in nutrition
3.PMID: 23682780 (2013) — Ocimum sanctum L (Holy Basil or Tulsi) and its phytochemicals in the prevention and treatment of cancer. · Nutrition and cancer
4.PMID: 39473808 (2024) — A Comprehensive Review of the Phytochemical Constituents and Bioactivities of Ocimum tenuiflorum. · TheScientificWorldJournal
5.PMID: 33650944 (2022) — Modulation of the hypothalamic-pituitary-adrenal (HPA) axis by plants and phytonutrients: a systematic review of human trials.
Government sources
No direct government monograph is available for this herb. The content below is AI-generated and has not been verified against an authoritative government source. Use the search links to check official sources before relying on this information.
An in vitro study demonstrated that an O. tenuiflorum and O. gratissimum herbal formulation-based oral rinse exhibited strong antifungal effects against Candida albicans, producing a 13 mm zone of inhibition at 100 µg/mL, outperforming a commercial oral rinse [PMID:39290920].
Evidence DOral pathogens (antimicrobial)
In vitro studies showed that ethanolic extracts of O. tenuiflorum exhibited antimicrobial activity against Streptococcus mutans and Candida albicans [PMID:37082076], and silver nanoparticles synthesized using O. tenuiflorum demonstrated antimicrobial efficacy against oral pathogens [PMID:38550426].
Evidence CPeriodontal disease
A narrative review identified tulsi among various herbs used in the treatment of periodontitis, reporting therapeutic and prophylactic herbal applications in periodontal care [PMID:38290997].
Reviews synthesize experimental evidence that Ocimum sanctum and Ocimum basilicum possess neuroprotective potential in Alzheimer's disease, with bioactive compounds including polyphenols, flavonoids, essential oils, and triterpenoids that synergistically scavenge reactive oxygen species [PMID:40944265]. Another review proposed O. sanctum as a potential immunomodulator for the treatment of ischemic brain injury following stroke [PMID:36515030].
Evidence CCOVID-19 immunity
A literature review examined the role of Ayush Kwath (containing Tulsi/Holy Basil/Ocimum sanctum among other herbs) in improving immunity and combating SARS-CoV-2 infection, as recommended by the Ministry of AYUSH, Government of India [PMID:32837101].
Evidence CFemale reproductive health
A literature review of Ayurvedic herbal medicines examined data regarding the efficacy of Tulsi (Ocimum tenuiflorum) for menstrual irregularities, PCOS, infertility, and menopausal symptoms [PMID:38558676].
Evidence CRadioprotection
A review of radioprotective effects of plants from the Lamiaceae family found that Ocimum tenuiflorum exhibited relatively well-documented preventive properties, with essential oils and complex extracts containing phenolic acids and flavonoids showing radioprotective effectiveness in in vitro and in vivo models [PMID:33121420]. The aqueous extract of Tulsi and its flavonoids orintin and vicenin were shown to protect mice against γ-radiation-induced sickness and mortality [PMID:23682780].
· Nutritional neuroscience
6.PMID: 28400848 (2017) — The Clinical Efficacy and Safety of Tulsi in Humans: A Systematic Review of the Literature. · Evidence-based complementary and alternative medicine : eCAM
7.PMID: 39771214 (2024) — Harnessing the Antibacterial, Anti-Diabetic and Anti-Carcinogenic Properties of Ocimum sanctum Linn (Tulsi). · Plants (Basel, Switzerland)
8.PMID: 38351693 (2024) — Ocimum sanctum: The Journey from Sacred Herb to Functional Food. · Recent advances in food, nutrition & agriculture
9.PMID: 20509321 (2009) — The science behind sacredness of Tulsi (Ocimum sanctum Linn.). · Indian journal of physiology and pharmacology
10.PMID: 23629478 (2013) — Ocimum sanctum Linn. (Tulsi): an ethnomedicinal plant for the prevention and treatment of cancer. · Anti-cancer drugs
11.PMID: 36515030 (2024) — Ocimum sanctum [Tulsi] as a Potential Immunomodulator for the Treatment of Ischemic Injury in the Brain. · Current molecular medicine
12.PMID: 38290997 (2024) — Phytotherapy in periodontics as an effective and sustainable supplemental treatment: a narrative review. · Journal of periodontal & implant science
13.PMID: 35578854 (2022) — Chemotherapeutic Role of Polyphenols Present in Ocimum sanctum. · Anti-cancer agents in medicinal chemistry
14.PMID: 25624701 (2014) — Tulsi - Ocimum sanctum: A herb for all reasons. · Journal of Ayurveda and integrative medicine
15.PMID: 34331753 (2023) — Ocimum Sanctum: An All-Round Treatment for Cancer? · Alternative therapies in health and medicine
16.PMID: 36200220 (2023) — A Glance at the Phytochemical and Ethno-pharmacological Understanding of Four Ocimum Species. · Current pharmaceutical biotechnology
17.PMID: 37567911 (2023) — Characterizing the circadian connectome of Ocimum tenuiflorum using an integrated network theoretic framework. · Scientific reports
18.PMID: 37008142 (2023) — Exploring the Chemistry of Ocimum Species under Specific Extractions and Chromatographic Methods: A Systematic Review. · ACS omega
19.PMID: 33121420 (2022) — Radioprotective Effects of Plants from the Lamiaceae Family. · Anti-cancer agents in medicinal chemistry
20.PMID: 36770859 (2023) — An Update on the Therapeutic Anticancer Potential of Ocimum sanctum L.: "Elixir of Life". · Molecules (Basel, Switzerland)
21.PMID: 16170979 (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
22.PMID: 32837101 (2022) — Immunity against COVID-19: Potential role of Ayush Kwath. · Journal of Ayurveda and integrative medicine
23.PMID: 40944265 (2025) — The Neuroprotective Potential of Ocimum Plant Species: Seasoning the Mind with Sweet and Holy Basil. · Nutrients
24.PMID: 39290920 (2024) — Antifungal Activity of Ocimum tenuiflorum and Ocimum gratissimum Herbal Formulation-Based Oral Rinse Against Candida albicans. · Cureus
25.PMID: 37082076 (2022) — Antimicrobial efficiency of Tinospora cordifolia and Ocimum tenuiflorum against Streptococcus mutans and Candida albicans. · Journal of oral and maxillofacial pathology : JOMFP
26.PMID: 38550426 (2024) — Antimicrobial Activity of Silver Nanoparticles Synthesized Using Ocimum tenuiflorum and Ocimum gratissimum Herbal Formulations. · Cureus
27.PMID: 34218781 (2021) — Eugenol as a Potential Drug Candidate: A Review. · Current topics in medicinal chemistry
28.PMID: 30475878 (2018) — Product authenticity versus globalisation-The Tulsi case. · PloS one