Tonic water (or Indian tonic water) is a carbonated soft drink in which quinine is dissolved. Originally used as a prophylactic against malaria, tonic water usually now has a significantly lower quinine content and is consumed for its distinctive bitter flavor, though it is nowadays also often sweetened. It is often used in mixed drinks, particularly in gin and tonic.

Under ultraviolet light, the quinine in tonic water fluoresces.


In early 19th century India and other tropical posts of the British Empire, medicinal quinine was recommended to British officials and soldiers, where it was mixed with soda and sugar to mask its bitter taste, creating tonic water.

The first commercial tonic water was produced in 1858.[1] The mixed drink gin and tonic also originated in British colonial India, when the British mixed their medicinal quinine tonic with gin and other ingredients to make the bitter medicine more palatable.[2] Soldiers in India were already given a gin ration, and the sweet concoction made sense.[3]

Quinine contentEdit

Medicinal tonic water originally contained only carbonated water and a large amount of quinine; most modern tonic waters contain comparatively less quinine, and are often enhanced by citrus flavors. As a result of the lower quinine content, tonic water is less bitter, and is also usually sweetened, often with the addition of high-fructose corn syrup or sugar. Some manufacturers also produce diet (or "slimline") tonic water, which may contain artificial sweeteners such as aspartame. Traditional-style tonic water with little more than quinine and carbonated water is less common, but may be preferred by those who desire the bitter flavor.

In the United States, the US Food and Drug Administration (FDA) limits the quinine content in tonic water to 83 ppm[4] (83 mg per liter if calculated by volume), while the daily therapeutic dose of quinine is in the range of 500–1000 mg,[5] and 10 mg/kg every eight hours for effective malaria prevention (2100 mg daily for a 70 kilograms (150 lb) adult).[6] It is often recommended as a relief for leg cramps, but medical research suggests some care is needed in monitoring doses.[7] Because of quinine's risks, the FDA cautions consumers against using "off-label" quinine drugs to treat leg cramps.[8]


Tonic water is often used as a drink mixer for cocktails, especially gin and tonic. Vodka tonic is also popular. Tonic water with lemon or lime juice added is known as bitter lemon or bitter lime, respectively.


The quinine in tonic water will fluoresce under ultraviolet light. In fact, the sensitivity of quinine to ultraviolet light is such that it will appear visibly fluorescent in direct sunlight against a dark background.[9][10]

See alsoEdit


  1. ^ Raustiala, Kal (28 August 2013). "The Imperial Cocktail". Slate. The Slate Group. Retrieved 30 August 2013.
  2. ^ Tonic water: sweet, bitter medicine. Retrieved 30 December 2009.
  3. ^ Raustiala, Kal (28 August 2013). "Gin and tonic kept the British Empire healthy: The drink's quinine powder was vital for stopping the spread of malaria". Retrieved 25 June 2014.
  4. ^ "21 CFR §172.575 Quinine" (PDF). Retrieved 15 December 2008.
  5. ^ "Quinine". Tropical Plant Database. Section "Current practical uses": Raintree Nutrition. Retrieved 10 July 2011.
  6. ^ Achan, J (2011). "Quinine, an old anti-malarial drug in a modern world: role in the treatment of malaria". Malaria Journal. 10 (144): 1–12. doi:10.1186/1475-2875-10-144. PMC 3121651. PMID 21609473.
  7. ^ Brasić, JR (1999). "Should people with nocturnal leg cramps drink tonic water and bitter lemon?". Psychol Rep. 84 (2): 355–67. doi:10.2466/pr0.1999.84.2.355. PMID 10335049. S2CID 42278918.
  8. ^ "FDA Orders Unapproved Quinine Drugs from the Market and Cautions Consumers About Off-Label Quinine to Treat Leg Cramps". United States Food and Drug Administration. 11 December 2006. Archived from the original on 13 January 2017. Retrieved 26 April 2017.CS1 maint: bot: original URL status unknown (link)
  9. ^ Steve Fentress (9 August 2011). "The Blue Glow Of Quinine". Retrieved 16 February 2020.
  10. ^ Suzanne Elvidge (24 August 2012). "Seeing Ultraviolet Light: Tonic Water in Sunlight". Science Project Ideas. Retrieved 16 February 2020.

External linksEdit