Key takeaways:
Tonic water is a sweetened soda that contains a bitter-tasting chemical compound called quinine. Quinine is actually an ingredient in some medications that treat conditions like malaria.
Some people use quinine as a treatment for leg cramps, but this isn’t recommended by healthcare professionals. There isn’t enough quinine in tonic water to treat health conditions.
Tonic water is fine to enjoy in small amounts. But, because of the sugar and quinine, it’s best to limit the amount of tonic water you drink.
What’s the best drink for staying hydrated? Water is ideal for day-to-day hydration. But there are certain times when other drinks may be an even better choice.
What is sparkling water, anyways? Various types of carbonated waters — like club soda, seltzer, and mineral water — look similar, but are they the same? Learn the health benefits of each.
Alkaline water versus regular water: Alkaline water is hydrating and safe to drink. But be wary of some of the health claims about it.
Tonic water is probably best known for its role as a mixer in cocktails. This clear carbonated beverage looks identical to many types of carbonated water. But tonic water isn’t just carbonated water. It also contains a compound called quinine, plus sugar or artificial sweeteners.
Let’s take a closer look at the ingredients in tonic water and how this drink can affect your health.
Tonic water is a clear soda that contains water, sugar, and citric acid. What makes tonic water unique is the addition of quinine. The combination of ingredients in tonic water results in a tart, sweet, and bitter-tasting beverage.
Quinine comes from the bark of the cinchona tree and has been used to treat malaria since the 1600s. Though quinine is still used to treat malaria, it’s fallen out of favor as a frontline treatment because it comes with many side effects.
The quinine in tonic water gives the classic gin and tonic cocktail its distinct bittersweet flavor. In fact, gin and tonic cocktails were served to members of the British Royal Navy for the antimalarial effect. These days, though, tonic water is much lower in quinine and doesn’t have an antimalarial effect.
There are regulations that limit how much quinine can be added to tonic water. The FDA says quinine must not exceed 83 parts per million. That’s equal to 83 mg quinine per liter of tonic water. Plus, the label must clearly list quinine as an additive, in case anyone has a quinine allergy.
Here are the nutrition facts for tonic water.
Nutrient | Tonic water (12 fl oz) |
Calories | 125 kcal |
Protein | 0 g |
Carbohydrates | 32 g |
Sugar | 32 g |
Fat | 0 g |
Sodium | 45 mg |
As the table above shows, tonic water is mostly water and sugar. Tonic water also comes in a sugar-free version, which is made with artificial sweeteners, such as saccharin and/or aspartame. The sugar-free version contains no carbohydrates, sugar, or calories.
Quinine can be good for you if it’s used as directed by a healthcare professional as a treatment for malaria. But, as mentioned above, there are newer malaria medications that are more commonly used today. This is because there are several potential side effects associated with quinine.
As an ingredient in tonic water, quinine is safe because of the small dose. But drinking too much tonic water may cause side effects from the quinine, such as:
Tinnitus (ringing in the ears)
Nausea and vomiting
Stomach cramps
Diarrhea
Confusion
Consuming larger amounts of quinine — such as from a medication or supplement — may have additional, more severe side effects, such as:
Abnormal heartbeat
Severely low blood counts, which can lead to bleeding problems
Acute kidney failure
Liver toxicity
Neurological issues
Allergic reactions
Tonic water doesn’t have any real health benefits.
Some people think tonic water is good for digestion or upset stomach. But there’s no evidence that this is true.
People also drink tonic water because they’ve heard that quinine can help relieve nighttime leg cramps. But the evidence to support this claim is weak. In fact, the National Library of Medicine cautions against using quinine for leg cramps. They say that it isn’t effective and it may cause health risks, as outlined above.
No, drinking tonic water isn’t the best way to hydrate due to its high sugar and calorie content. Even though the main ingredient is water (and the word “water” is in its name), tonic water is actually a soda.
The American Heart Association recommends drinking water for the best hydration, since it contains no calories or sugar.
Tonic water contains 32 g of sugar per 12 oz serving, which is equal to 8 tsp of sugar. For comparison, this is almost the amount of sugar that you’d find in the same amount of cola (37 grams of sugar, or 10 tsp).
Excess sugar is linked to increased risk of:
Heart disease
Diabetes
Weight gain
Plus, studies show that drinking sugary beverages increases risk for kidney disease and kidney stones, among other health conditions.
There are no specific guidelines for who should avoid tonic water. But some people should avoid quinine medication or supplements. You should avoid quinine if you:
Are allergic to quinine
Are pregnant or breastfeeding
Take certain medications, such as blood thinners, antidepressants, or cholesterol-lowering medications
Have an irregular heartbeat
Have heart, kidney, or liver disease
If you fall into any of these categories, it’s best to try to limit your tonic water intake.
Tonic water is fine to enjoy in small amounts if you enjoy the taste. But it doesn’t have any health benefits. In fact, it may be harmful in high amounts. As with any soda, tonic water is high in sugar. So, drinking a lot of tonic water can be bad for your blood sugar and metabolic health. And high doses of quinine may lead to serious side effects and organ damage. An occasional tonic drink is unlikely to cause any problems. But, if you have any ongoing medical conditions or take medications, it’s best to check with your primary care provider before drinking tonic water.
American Heart Association. (2024). Rethink your drink: How to reduce sugary drinks.
El-Tawil, S., et al. (2015). Quinine for muscle cramps. Cochrane Database of Systematic Reviews.
Marie, C., et al. (2022). Malaria. Merck Manual.
MedlinePlus. (2017). Quinine.
Menakuru, S. R. (2021). Disseminated intravascular coagulation due to drinking tonic water. Cureus.
National Center for Biotechnology Information. (2024). PubChem Compound Summary for CID 3034034, Quinine.
Sánchez-Lozada, L. G., et al. (2019). The perils of rehydrating with soft drinks following heat and exercise. American Journal of Physiology: Regulatory, Integrative and Comparative Physiology.
Simonetti, O., et al. (2022). The history of gin and tonic: The infectious disease specialist long drink. When gin and tonic was not ordered but prescribed. Le Infezioni in Medicina.
Stanhope, K. L., et al. (2014). Adverse metabolic effects of dietary fructose: Results from recent epidemiological, clinical, and mechanistic studies. Current Opinion in Lipidology.
U.S. Department of Agriculture. (2019). Beverages, carbonated, tonic water. FoodData Central.
U.S. Department of Agriculture. (2022). Soft drink, cola. FoodData Central.
U.S. Food and Drug Administration. (2024). Code of federal regulations title 21: Sec. 172.575 Quinine.