Water Pills: Exposed

  1. What are legit medical reasons to take water pills?

Water pills as a general class are among the most commonly prescribed medications.  Known in medical terms as diuretics, they are often used for patients with hypertension (to help reduce blood pressure), heart failure (to help prevent fluid buildup in the lungs and elsewhere in the body), and leg swelling (peripheral edema) from various other causes including venous insufficiency of the legs and chronic liver disease.

2. What’s in water pills—are they dangerous or habit-forming?
The most common type of water pill (known as a ‘loop diuretic’) contains substances that make the kidneys pass out more fluid.  They do this by interfering with salt and water reabsorption in a structure within the kidneys called the Loop of Henle, hence the name ‘loop diuretic.’   Any fluid which has accumulated in the body is then drawn into the blood stream to replace this extra fluid which was passed out by the kidneys.


When routine low-range dosing is used, side effects are uncommon from water pills which is why they are so widely prescribed.  However, with repeated use and/or higher doses, serious side effects can occur such as:

-abnormal electrolyte balance in the blood, leading to low levels of    potassium, sodium and a high level of calcium.

-severe dizziness upon standing up due to low blood pressure

-abnormal heart rhythms, weakness, and confusion

-if you have gout or kidney stones, symptoms can be aggravated and/or flares can occur with higher frequency

-There is even something called “diuretic-induced edema” which refers to swelling that occurs when water pills are overused.  The kidney, for reasons which are not clear, goes into a permanent mechanism of retaining more sodium and water than it needs.  This chronic swelling is quite difficult to treat and reverse, and is obviously not the desired effect of using a water pill!


Water pills are not addictive in the traditional sense.  However, with repeated use the kidney can compensate to counteract their effects by increasing salt and water reabsorption at other sites in the kidney.  Therefore, over time, water pills’ effectiveness can decrease.

  1. Water pills are often promoted as a dieting aid. When is using water pills to lose weight useful, and when does it become dangerous?
    As a diet aid, water pills are generally unhelpful. As mentioned above, with repeated use the kidneys can compensate for their use, negating any initial weight loss effects. And when you stop using water pills, your kidneys go back to reabsorbing the normal amount of water and salt for your body, so any weight lost will be immediately regained.  Also, one must remember the real goal of weight loss:  it is not to make the scale go down by 2-3 pounds, but to lose body fat.  Water pills do nothing to target excess body fat mass.

In addition, users of water pills can be subject to all the side effects mentioned previously – some of which can be very serious.


  1. The commercials for these types of diet aids often target women wanting to look skinnier, as opposed to the real medical reasons people take them. What’s the best way for women to decipher between which ones are legit, and which are just a money grab?

In my Obesity Medicine specialty practice, I actively discourage my patients from taking any over-the-counter water pills for weight loss.  My reasons are that as mentioned above, no permanent weight loss or body fat reduction occurs.  Also, some of these products contain ingredients that can cause serious side effects and can lead to dangerous health situations when used without medical monitoring.  Also, most of these over-the-counter products are not tested or regulated by the FDA, so the listed ingredients and amounts may not be accurate, and may even be toxic (either in themselves, or in interaction with another medication you may be taking).  Many manufacturers of herbal water pills make false claims about the health benefits of their products that have not been studied in research trials.


5. Are there any other factoids about water pills you feel women should be made aware of?

The one true indication for occasional use of a water pill in an otherwise healthy woman might be leg swelling or bloating due to premenstrual syndrome, or what is known as Idiopathic Edema (edema where the cause is never identified).   I would encourage all patients to discuss this with their PCP or OB/GYN for a prescription for occasional use if needed.  That way, patients can feel comfortable that their use of the water pill will be medically monitored, reducing the chance of toxicity or a serious side effect.


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