Basil and Warfarin

Publication Date: 
By: Alere Staff

  Basil, a sun-loving herb of the Mediterranean region, is a common addition to many Italian and Mediterranean meals. A well-known pleasant spice, basil can now be found beyond Italy in Asia, Africa, Central and Southern America.1 While the herb is used in cooking, it can also be the source of essential oils, aroma compounds and as an attractive fragrant ornamental. Containing more than 30 different varieties, basil herbs and shrubs are spread throughout the world.2

Basil the Herb 

When it comes to enjoying the basil herb, it can be relished either fresh or dried. Basil has also been known to stimulate a person’s appetite and basil tea is said to aid people with dysentery, nausea and stomach distress from gas.3 While the seeds of the basil plant have their uses in oils, the key parts for cooking are the green leaves. While some small stems are okay, the thicker stems and stalks should be avoided as they are more bitter.3 The stems also contain compounds that can turn a tasty pesto more of a dark brown color rather than the favored green. 

With a sweet and aromatic scent, basil is commonly combined with tomatoes, pickled olives, capers and garlic.1 Since the basil flavor is easily overpowered by other herbs, it is usually used alone. Some herbs that may mix well include oregano, summer savory, rosemary and sage.3 The flavor of basil is also easily destroyed by prolonged heat. Due to this chopped, basil leaves are frequently added after the cooking process, sprinkled on top of the dish. 

Basil and Warfarin 

If you are a patient on warfarin, basil is something that you should be aware of either dried or fresh. Five leaves of fresh basil, around 2.5 grams, contain about 10.4 micrograms, a low value of vitamin K. One teaspoon, or about 0.7 grams, of dried basil also contains a low value of vitamin K at 12 micrograms. Higher amounts of fresh basil contain medium levels of vitamin K. Two tablespoons of fresh chopped basil, about 5.3 grams, contains a medium vitamin K value of 22 micrograms while about ¼ cup of fresh basil leaves, about 6 grams, contains 24.9 micrograms. Dried basil contains higher values of vitamin K. One tablespoon of dried leaves, about 2.1 grams, contains 36 micrograms of vitamin K while 1 tablespoon ground, about 4.5 grams, contains 77.2 micrograms of vitamin K.4


  1. Katzer, G. Basil (Ocimum basilicum L.) Gernot Katzer’s Spice Pages. Sep. 30, 2012. Retrieved  from the website:
  2. Simon, J.E. et al. Basil: A Source of Aroma Compounds and a Popular Culinary and Ornamental Herb. Perspectives on new crops and new uses. 1999. J. Janick (ed.), ASHS Press, Alexandria, VA.
  3. Trowbridge, P. Basil Cooking Tips. 2016. Retrieved from the website:
  4. US Department of Agriculture, Agricultural Research Service, Nutrient Data Laboratory. USDA National Nutrient Database for Standard Reference, Release 28. Version Current:  September 2015, slightly revised May 2016.  Internet:  /nea/bhnrc/ndl.