Should I Take Spironolactone for Weight Loss?

Obesity and overweight affects around 42% of adults in the United States, according to the Centers for Disease Control and Prevention (CDC) and the National Center for Health Statistics. Many people to turn to fad diets, fat-burning supplements, and prescription drugs for quick weight loss.

One drug prescribed for weight loss is spironolactone. However, no scientific study has evaluated this medication specifically for weight loss. Though often prescribed, it remains unclear if spironolactone is effective for losing weight.

What Is Spironolactone?

Spironolactone (Aldactone) is a prescribed diuretic, which means that it causes fluid elimination. Spironolactone was approved by the U.S. Food and Drug Administration (FDA) in 2001 to treat a variety of health issues.

The primary function of spironolactone is treating fluid retention in the body, which often leads to weight loss. However, the weight loss that occurs consists of only water weight. Diuretics effectively flush out water from the body, not fat.

Spironolactone also blocks the body's androgen receptor and some of the production of androgens. Androgens are a group of hormones responsible for male traits and reproductive activity. Androgens are made in the testes, ovaries, and adrenal glands. Testosterone is the main androgen in men and converts into the estrogen hormone in women. 

Prescribed Uses

There are some prescribed uses for spironolactone. For instance, a woman with PCOS (causing high testosterone levels) who experiences hair loss or excess body hair may be prescribed spironolactone to relieve these symptoms.

Spironolactone and other diuretics are also prescribed for high blood pressure and for edema (fluid retention) caused by conditions such as heart, liver, or kidney disease. But people also use spironolactone off-label for weight loss and fat loss.

Spironolactone is prescribed to treat several health conditions, including the following:

• Fluid buildup from liver disease
• High blood pressure
• Low potassium (it raises levels, giving its name “potassium-sparing”)
• Symptoms related to excess androgen production in females

Women who produce too much testosterone are often prescribed spironolactone to decrease the symptoms caused by an overproduction of this hormone. The following conditions are related to excess androgen production in females:

• Acne
• Excessive body or facial hair growth
• Female-pattern hair loss
• Polycystic ovary syndrome (PCOS)

Spironolactone for Weight Loss 

Spironolactone for weight loss occurs by causing the elimination of water from the body, reducing scale weight, but it does not cause fat loss directly. Losing body water is not the same as losing body fat. You may become less bloated using a diuretic, but the weight will return once body fluid levels return to normal. It is also important to note that there are no scientific studies that have examined spironolactone specific to weight loss, so its effectiveness for this purpose remains unknown.

That said, in some cases, taking spironolactone might result in the loss of body fat, although it is not the spironolactone that is causing the fat loss. For instance, a woman who already has high testosterone levels that contribute to insulin resistance (making it difficult to lose body fat) may find that lowering these levels with spironolactone helps with fat loss. So the spironolactone is helping to treat the insulin resistance which then makes it less difficult to lose body fat.

On the other hand, testosterone often raises metabolism and makes building muscle easier. This makes lowering the levels with medication a double-edged sword. Although spironolactone may relieve symptoms caused by fluid retention and could be helpful for specific health conditions, there is insufficient evidence to suggest that it promotes healthy long-term weight loss.

Side Effects

Taking any prescribed medication, including spironolactone, comes with side effects. Spironolactone can cause changes in blood levels of potassium. If changes are severe enough, this can result in death. Spironolactone can also interact with other drugs and may be harmful if taken during pregnancy.

Some of the most common side effects of spironolactone include:

• Breast tenderness
• Dizziness
• Drowsiness
• Dry mouth
• Enlarged breast tissue in men (gynecomastia)
• Headache
• Irregular menstrual periods
• Post-menopausal vaginal bleeding
• Stomach upset, vomiting, and diarrhea

More severe side effects include:

• Arrhythmia
• Confusion
• Decreased urination 
• Difficulty breathing or swallowing
• Flu-like symptoms
• Muscle pain or weakness
• Numbness or tingling
• Serious skin reactions
• Unusual bleeding or bruising

A Word From Verywell

Spironolactone is approved by the FDA to treat a variety of health conditions. But health experts warn that no one should ever take a water pill to lose weight.

Spironolactone should not be taken unless prescribed by a healthcare professional. If you are taking spironolactone, your blood levels should be monitored regularly. Consult your healthcare provider prior to taking any medications.