Spironolactone for Weight Loss: Is It Right for You?

Obesity 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 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.

Woman holding spironolactone and benefits are listed
Illustration by Emily Roberts, Verywell.

What Is Spironolactone?

Spironolactone (Aldactone) is a prescribed diuretic that causes fluid elimination. The medication was approved by the U.S. Food and Drug Administration (FDA) in 2001 to treat several health issues.

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

Spironolactone is described as a potassium-sparing diuretic or water pill. As your body flushes water, spironolactone acts to prevent your body from absorbing too much sodium and keeping your potassium levels from getting too low.

Spironolactone also blocks the body's androgen receptor and some production of androgens, 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. 

Spironolactone Prescribed Uses

There are prescribed uses for spironolactone, including for women with PCOS, which causes high testosterone levels, hair loss, and excess body hair. Spironolactone and other diuretics are also prescribed for high blood pressure and edema, or fluid retention, caused by conditions such as heart, liver, or kidney disease. People also use spironolactone off-label for weight loss and fat loss.

Spironolactone is prescribed to treat several health conditions, including:

  • 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 and reducing scale weight, but it does not result in fat loss. Losing water weight 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 no scientific studies examined spironolactone for weight loss, so its effectiveness 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. Spironolactone helps treat insulin resistance, making it easier 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 of Spironolactone

Taking 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 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

Though it may help in specific cases, spironolactone is not a weight-loss drug. Spironolactone needs to be used with caution and under the supervision of a qualified healthcare provider.

A Word From Verywell

Spironolactone is approved to treat a variety of health conditions by the FDA, but 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.

7 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Adult obesity facts.

  2. U.S. National Library of Medicine. Spironolactone.

  3. Mazza A, Fruci B, Guzzi P, et al. In PCOS patients the addition of low-dose spironolactone induces a more marked reduction of clinical and biochemical hyperandrogenism than metformin aloneNutr Metab Cardiovasc Dis. 2014;24(2):132-139. doi:10.1016/j.numecd.2013.04.016

  4. U.S. National Library of Medicine. Spironolactone and hydrochlorothiazide.

  5. Faconti L, Mills CE, Govoni V, et al. Cardiac effects of 6 months' dietary nitrate and spironolactone in patients with hypertension and with/at risk of Type 2 diabetes, in the factorial design, double-blind, randomized controlled VaSera trialBr J Clin Pharmacol. 2019;85(1):169–180. doi:10.1111/bcp.13783

  6. Sirmans SM, Pate KA. Epidemiology, diagnosis, and management of polycystic ovary syndrome. Clin Epidemiol. 2013;6:1-13. doi:10.2147/CLEP.S37559

  7. Kulshreshtha B, Gupta N, Ganie MA, Ammini AC. Effect of metformin and spironolactone therapy on OGTT in patients with polycystic ovarian syndrome - a retrospective analysisGynecol Endocrinol. 2012;28(10):823-826. doi:10.3109/09513590.2012.671394

Additional Reading
Darla Leal

By Darla Leal
Darla Leal is a Master Fitness Trainer, freelance writer, and the creator of Stay Healthy Fitness, where she embraces a "fit-over-55" lifestyle.