Holy basil’s protective action is due, in part, to its free radical scavenging effect. This also reduces oxidative cellular and chromosomal damage from radiation.6 These actions ultimately help reduce end-organ damage and improve post-radiation recovery. Limited clinical studies have shown promise with being able to deliver higher doses of therapeutic radiation in patients taking holy basil without increasing the unwanted side effects of the radiation.6 The protective mechanisms are thought to be due to the increase in antioxidant activity, alteration in gene expression, induction of apoptosis, and the inhibition of angiogenesis and metastasis.7 A substantial part of this protective action is due to enhancement of the liver enzyme systems that detoxify and cleanse the bloodstream of damaging substances. 

Safety, interactions, side effects

Holy basil is not recommended for pregnant or nursing mothers or young children. It should also be used with caution in patients with diabetes due to its potential for inducing hypoglycemia.6 Allergic reactions are always a concern with any compound. Persons with allergic histories should be cautious with first-time use of holy basil. 

How supplied, dose, cost 

Holy basil is usually found as either chopped and dried leaves, tea, or tincture. Essential oil of holy basil is also becoming very popular. Holy basil products cost from $15 to $45, depending on the quantity and concentration. Also, ‘growing your own’ is becoming increasingly attractive and a packet of several hundred non-GMO seeds can be purchased for as little as $4. Dried leaves are usually dosed by steeping one-half teaspoon in hot water to make a tea and consuming two to three times daily.6 


As with all homeopathic remedies, there are many pros and cons. There does not appear to be a substantial downside to the use of holy basil. However, there are still many holes in the research before healthcare providers can safely recommend its use. The concern always exists, especially in cases of cancer and other life-threatening diseases, that patients could unknowingly rely too heavily on this remedy and possibly feel that it could replace traditional therapy. As long as healthcare providers thoroughly educate their patients as to the adjunctive place of holy basil in a treatment regimen, cautious use seems both safe and likely beneficial.

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  2. Cohen MM. Tulsi-Ocimum sanctum: A herb for all reasons. J Ayurveda Integr Med. 2014;5:251-259.
  3. Renter E. Holy basil benefits: Growing your own medicine. Available at http://naturalsociety.com/holy-basil-benefits-growing-your-own-medicine. Posted March 7, 2013. Accessed January 10, 2017.
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  6. Tulsi (Ocimum sanctum) as radioprotector in head and neck cancer patients undergoing radiation therapy. Biomedicine. 2012; 32:39-44.
  7. Baliga MS, Rao S, Rai MP, D’Souza P. Radioprotective effects of the Ayurvedic medicinal plant Ocimum sanctum Linn. (holy basil): A memoir. J Cancer Res Ther. 2016;12:20-27.
  8. Skidmore-Roth L. Mosby’s Handbook of Herbs & Natural Supplements. 3rd ed. St. Louis, MO: Elsevier Mosby; 2006.

This article originally appeared on Clinical Advisor