Water pills—they sound relatively harmless, no? After all, water is generally associated with all things good: glowing skin, a speedy metabolism, and the ultimate hangover cure. Yet here’s an interesting tidbit: If not taken appropriately, water pills (known as loop diuretics in the medical community) can actually be pretty dangerous, and should only be taken under a doctor's supervision. Why? Because prescription water pills are for people with high blood pressure or patients recovering from heart failure. Yet they’re more casually known as an expedited way to try to shed pounds and/or water weight—by people with perfectly pumping hearts.
The term “water pill,” in fact, has nothing to do with the scientific composition of the medication and everything to do with their prescribed purpose: to relieve fluid retention. As we know all too well, one doesn’t have to be recovering from a heart attack to retain some extra water.
So it’s easy to see where things could become, shall we say, murky. Though valid when needed for legitimate health concerns, over the counter water pills tout some understandably tempting claims. But are water pills a safe solution in the fight against bloat? We tapped a couple of experts—Neeru Bakshi, MD, and Tara Condell—to get their medical stance on the topic. The general consensus: If you are looking into water pills, be sure to only take them under a doctor's supervision.
Ahead, learn everything you need to know about water pills, including how they work and the difference between prescription and over-the-counter diuretics.
Meet the Expert
What Are Water Pills?
Essentially, Bakshi tells us, “Water pills—also known as diuretics—are a class of medication used to help the kidneys decrease the amount of water in the body." Typically, she adds, they’re prescribed to a patient by a medical professional to help with high blood pressure, heart failure, and edema. “If taken at the prescribed dosage, they can be very useful for people who actually need to take them,” she says. Some people have likened water pills as a solution to migraines, but there's little evidence to back this up, and experts agree you should only take them as directed by your physician.
How Do Water Pills Work?
Water pills "work by having the kidneys remove sodium from the body, and the water then follows the sodium," says Bakshi. This decrease in fluids running through your veins and arteries is what gives water pills their "anti-bloating" properties. When it comes to your natural fluid intake while on diuretics, it's best to listen to the instruction of your doctor—especially if you have kidney or heart issues—as this depends on your individual calorie intake and weight.
From a nutritional standpoint, Condell notes that diuretics are useful for a variety of medical conditions—even for treating acne—but should always be used under the care of a physician. Typically, water pills are taken orally once a day, and you may notice more urine passing within the first two weeks of use.
Common Risks and Side Effects
When it comes to water pills, there are common side effects and then there are more serious ones, especially when they're not being taken under the care of a doctor. Nasty side effects include but aren't limited to "excessive urination, dehydration, constipation, dizziness, low blood pressure, muscle cramping, and elevated heart rate,” in addition to potential interactions with other medications. Which is why, Bakshi says, you should really only take these types of pills while monitored by your physician.
It’s important to note, however, that when taken as prescribed, diuretics can be safe. Side effects are still a possibility, but if taken under the care of a medical professional, these symptoms can be dealt with in a prompt and safe manner.
Prescription vs. Over-the-Counter Water Pills
There's an important differentiation when it comes to water pills: diuretics that are prescribed and diuretics that are sold over-the-counter. Considering that water pills are often taken as a weight-loss solution, it's important to get information from both a medical and nutritional standpoint.
This is important. Unlike prescribed diuretics, over-the-counter water pills are not regulated by the FDA. In other words, “The ingredients listed on the box may not actually be what is in the pill you are taking,” says Bakshi. She continues, “There is also no guarantee of the concentration of the ingredients or promise that the listed benefits of the drug are what you should achieve.” (In other words, a functioning, healthy human shouldn’t need to take water pills in the first place).
Which left us wondering, how are water pills even allowed to be sold over the counter? According to Bakshi, oftentimes, certain once-prescribed medications can be sold over the counter once deemed safe to do so. "This is the case for diuretics and other medications, like ones for heartburn. That being said, when a medication is able to be sold over the counter, it can lose the oversight by the FDA (as noted earlier) and thereby, not need to follow the same regulations as prescribed medication for safety.” She adds: “Just because a medication is available over the counter does not mean that it is safe for all people to take.”
Do Water Pills Cause Weight Loss?
According to our nutritional expert, Condell, “[water pills] should not be a method for tackling weight loss.” And again, she adds that they should be used under the care of a physician. (Do we sound like a broken record yet?). Bakshi, backs her up, explaining that historically, diuretics have been a medication that people use to try to lose weight, though it's not an effective strategy, and if anything, they might cause you to gain weight.
“Diuretics do not help in weight loss but can temporarily decrease someone’s weight on the scale as they are losing water. As a response to this, the body may try to retain more water, causing swelling and an increase in weight as measured on a scale. In turn, the person may think that they need to take even more diuretics, leading them down a dangerous path.”
In short, it’s imperative to talk to a medical professional before taking water pills or any other type of diuretic. Be wary of over-the-counter options, and don't treat them as a quick de-bloating trick, which can result in dangerous side effects. To best determine if water pills are right for your health needs, speak to your personal physician.
Yale News. All water pills not equally effective against heart failure. Updated April 1, 2013.