Quinine in Tonic Water: Is It Safe? Side Effects, Potential Benefits & More

Believe it or not, one of the oldest cures for malaria, a compound called quinine, is now found in a popular “mixer” used to make cocktails: tonic water.

Before you get excited, here’s some disappointing news: The amount of quinine found in tonic water is very low, meaning it isn’t enough to provide much protection against infections or other symptoms.

While quinine itself does have the ability to kill certain parasites that can trigger illnesses, tonic water is a sugary drink that’s best to avoid in more than small amounts.

What Is Tonic Water?

Tonic water is a beverage that was first produced in the 1850s. Since then it’s become well-known as an ingredient used to make “gin and tonics” and other (mostly alcoholic) beverages.

The original formula for tonic water consisted of small amounts of powdered quinine, sugar and sparkling water (or “soda water”).

The reason that people continue to use tonic water today is for its signature bitter but sweet taste.

Quinine is the compound that gives tonic water its bitter qualities. It is also the same compound used to lend strong, bitter flavors to other products, such as those intended to taste like “bitter lemon.”

What Is Quinine?

Quinine is a compound with a bitter taste that is extracted from bark of the cinchona tree. The cinchona tree, sometimes called the “quinine plant,” is indigenous to parts of the world including Central and South America, Western Africa, and the Caribbean.

It was originally developed centuries ago as a medicine to fight malaria. Since at least the 1800s people have been consuming it to help prevent serious illnesses.

According to Dr. Sean O’Keefe, professor in the Department of Food Science at the Virginia Polytechnic Institute and State University, “quinine was the first successful drug used to treat human infectious disease. Malaria parasites have become somewhat resistant to quinine, and better drugs have become available, yet it is sometimes still used today.”

Why is quinine in tonic water? It’s thought that British soldiers first mixed it with sugar in order to improve its bitter taste.

Quinine powder dissolves in water and is much easier to get down when it’s sweetened and masked. This concoction eventually became sparkling tonic water, which was commercialized, bottled and shipped to tropical regions starting in the 1850s.

Quinine Benefits/Uses

What does quinine do to the body? Historically, quinine benefits and uses have included:

• Helping treat malaria, a serious illness that causes a fever and is caused by a protozoan parasite (often found in tropical regions) that invades the red blood cells. Quinine pills (Qualaquin) are available to assist in treatment of malaria by killing the parasite that causes it — however these pills don’t work as a preventative treatment.
• Decreasing leg cramps; it was once available over the counter for this purpose but is no longer recommended due to concerns over efficacy and safety.

Chloroquine (Aralen) is a synthetic version of quinine that is being studied, as of May 2020, as a potential treatment option for serious respiratory infections/viruses.

The jury is still out on whether or not chloroquine (and closely related hydroxychloroquine, or Plaquenil) may offer any hope to those who are very sick with respiratory infections, since these drugs have demonstrated immunosuppressive drug and also anti-parasite activities.

One 2020 study that was ended early found that chloroquine was not very effective and also led some patients to develop irregular heart rates that could potentially lead to fatal heart arrhythmia. Studies to date investigating hydroxychloroquine have mostly found that it failed to prevent or treat influenza and other viral illnesses.

Hydroxychloroquine is currently approved by the U.S. Food and Drug Administration for treatment of malaria, lupus and rheumatoid arthritis but not for other viruses, even though doctors sometimes prescribe it for other reasons “off label.”

Quinine Risks and Side Effects

Quinine has been officially approved for use in carbonated beverages as a flavor additive. According to the FDA, quinine in tonic water is not harmful as long as it is present in amounts less than than 83 parts per million.

Is quinine in tonic water bad for you? When consumed in higher amounts, it’s possible to experience side effects from it.

However, the amount used in commercial beverages today is considered very low and unlikely to pose a risk.

For sake of comparison, the amount of quinine found in half a liter of tonic water (assuming it contains 83 ppm quinine) equates to about 41.5 milligrams — but malaria treatments usually contain about 540 milligrams or more and are taken three times a day. This means that malaria treatments involve taking 40 times more than is found in tonic water.

While drinking normal amounts of tonic water isn’t likely to cause side effects, some people may experience adverse reactions if they have too much or are very sensitive to quinine, such as:

• nausea, diarrhea, vomiting and stomach cramps
• ringing in the ears and hearing loss
• changes in vision
• weakness and shakiness
• confusion
• nervousness
• changes in blood sugar
• rarely, serious complications like altered mental status, kidney damage, changes in heart rhythms, bleeding problems, seizures and allergic reactions

When used as a drug, why is quinine now banned? While it was once used to manage painful, nocturnal (night time) leg cramps, the FDA banned over-the-counter sales of this compound because it has potential to be misused, is not always effective and can cause side effects.

Some people seem to be particularly sensitive to its effects, especially when they take high doses, and because other safe leg cramp treatments are now available, it’s been deemed unnecessary and risky for this purpose.

Quinine and tonic water have potential to react with some medications, so they should be avoided by people who take:

• blood thinners
• antidepressants
• antibiotics
• antacids, seizure medications
• statins

(See more info here from the Cleveland Clinic regarding quinine interactions.)

You should never take quinine without a prescription from a doctor and should always follow dosage directions carefully if you do take it. Women who are pregnant or breastfeeding should also avoid quinine.

Benefits of Drinking Tonic Water

Is tonic water considered a healthy drink? Because it’s high in added sugar but doesn’t provide many other benefits, no, it’s not the best choice.

The small amounts of quinine found in tonic water are not enough to help treat diseases or symptoms like leg cramps. As Harvard Health Publishing points out, “Tonic water contains no more than 83 mg of quinine per liter—a much lower concentration than the 500 to 1,000 mg in the therapeutic dose of quinine tablets.”

Tonic water is also a relatively high-calorie, high-sugar drink that is often made with high fructose corn syrup or aspartame and artificial sweeteners if it’s “diet tonic water.” Drinking sweetened drinks can contribute to weight gain and blood sugar imbalances if consumed in large amounts, especially if mixed with alcohol, juices and other sugary ingredients.

Consumption of sugary drinks in general is linked with health problems, including:

• increased risk of gaining weight and developing obesity
• type 2 diabetes
• heart disease
• gout
• gastrointestinal issues
• tooth decay
• and other issues

Tonic Water Side Effects

If you drink lots of tonic water you may experience the same quinine side effects mentioned above, such as nausea, indigestion, etc.

Because there are a number of known quinine interactions, don’t drink more than small amounts of tonic water if you take daily medications unless you get your doctor’s approval first.

Conclusion

• What is tonic water? It’s a beverage that originated in the 1800s that is made with the bitter compound quinine, plus sugar and sparkling water.
• Historically, uses for quinine have been included treating malaria and leg cramps.
• The quinine plant began being used in the 1800s as a treatment for malaria since it can help kill the parasite that causes this illness. This compound is considered one of the first effective malaria drugs, although it’s not commonly used today.
• Quinine in tonic water is considered safe for humans to consume, but it must not to exceed 83 parts per million in order to prevent side effects. Drinking more than a small amount of tonic water is not recommended since it’s a high-calorie, sugary drink that doesn’t provide much benefit.