tonic water is safe, a glass of gin and tonic with ice and a lime slice

Q. My niece told me that drinking tonic water helped her restless legs syndrome. I tried sipping some before I went to bed, and it helps.

After I read in your column that the FDA bars doctors from prescribing quinine, I looked on the label. Quinine is listed as one of the ingredients. Is quinine harmful?

A. Some people are susceptible to quinine and develop irregular heartbeats or a life-threatening blood disorder when they consume it. It can also cause birth defects. The FDA banned it for treating leg cramps to prevent the serious side effects it can cause. Doctors are still permitted to prescribe it for malaria.

The dose of quinine found in tonic water is low, but we heard from one reader who suffered a severe reaction from drinking it:

“One evening I drank 5 ounces of tonic water; the next morning I was in the emergency room with a frightening skin reaction. I was hospitalized for many days.

“My platelet count dropped to 1,000. Now it has gradually come back up to 266,000. I was diagnosed with ITP (idiopathic thrombocytopenic purpura), triggered by the quinine in the water. It nearly killed me.”

Get The Graedons' Favorite Home Remedies Health Guide for FREE

Join our daily email newsletter with breaking health news, prescription drug information, home remedies AND you'll get a copy of our brand new full-length health guide — for FREE!

  1. Naomi

    I must tell you; my husband had pancreatic cancer. He developed a liking for tonic water, and would drink a large bottle every day. I noticed something online that warned against tonic water for people with cancer, because of the quinine content. I asked our oncologist about it, and he said it was alright for my husband to drink it. HOWEVER, he thought my husband was drinking probably a glass a day. Weeks later, I mentioned it again, and when he found out how much my husband was drinking daily, he told him to stop immediately.

    My husband died from pancreatic cancer, and I am NOT saying the tonic water caused his death. I am saying that be careful and only drink a small glass daily.

  2. tim

    Keep a liter bottle by the bed. Only a couple of swallows as needed for leg cramps, and mine get pretty severe! No problems.

    • tim

      Sweppes tonic water.

  3. aw

    Is it possible to be sensitive to it without actually being allergic? I too heard tonic water was good for leg cramps and had a couple of glasses of it that afternoon, while I sipped it I had a bit of a rush (not unpleasant) then a few funny rhythms and then my heart started racing, I was shaking and shivering cold then flushing red, dizzy and it upset my stomach. It did settle down after a few hours but left me feeling like I’d been hit by a truck, it was very frightening.

What Do You Think?

We invite you to share your thoughts with others, but remember that our comment section is a public forum. Please do not use your full first and last name if you want to keep details of your medical history anonymous. A first name and last initial or a pseudonym is acceptable. Advice from other commenters on this website is not a substitute for medical attention. Do not stop any medicine without checking with the prescriber. Stopping medication suddenly could result in serious harm. We expect comments to be civil in tone and language. By commenting, you agree to abide by our commenting policy and website terms & conditions. Comments that do not follow these policies will not be posted.

Your cart

Shipping and discount codes are added at checkout.