Apple cider vinegar is not a proven diuretic. No clinical studies have demonstrated that it increases urine volume the way actual diuretic medications do. The belief likely stems from the fact that drinking any acidic liquid in water can temporarily increase fluid intake and, by extension, urination. But that’s hydration at work, not a diuretic effect.
What the Research Actually Shows
The primary active compound in apple cider vinegar is acetic acid. Researchers have studied how acetic acid interacts with the kidneys, but the focus has been on urine composition rather than urine volume. In animal studies published in The Lancet’s eBioMedicine, oral vinegar changed what the kidneys excreted: it increased citrate in urine and reduced calcium. Those shifts are relevant to kidney stone prevention, not to flushing extra water from the body.
A clinical trial (the APUL study) tested apple cider vinegar in 36 patients specifically to measure changes in urinary citrate levels and urine pH, comparing it against lemonade, citrus soda, and coconut water. The study did not measure increased urine output as an outcome, because that’s not what researchers expected vinegar to do.
There is no peer-reviewed human trial showing that apple cider vinegar acts as a diuretic in the pharmacological sense, meaning it doesn’t cause your kidneys to excrete more sodium and water the way prescription water pills do.
Why It Gets Confused With a Diuretic
Several things feed this misconception. First, people typically dilute apple cider vinegar in a full glass of water before drinking it. Drinking extra water naturally leads to more urination. Second, apple cider vinegar has a mild effect on potassium levels, which is something true diuretics also do. That overlapping side effect creates the impression they work the same way, but the mechanisms are different. Prescription diuretics act directly on the kidneys’ filtration system to force sodium and water excretion. Apple cider vinegar doesn’t do that.
Third, there’s a long tradition of folk remedies labeling acidic or fermented drinks as “cleansing” or “detoxifying,” and diuretic properties get lumped into that category without much scrutiny.
The Potassium Risk Is Real
Even though apple cider vinegar isn’t a diuretic, it shares one serious concern with diuretic drugs: it can lower potassium levels. Case reports have documented cardiac arrest linked to heavy apple cider vinegar consumption causing severe potassium depletion. These cases involved large, sustained intake well beyond normal use, but they illustrate that the risk isn’t hypothetical.
This matters most if you already take medications that affect potassium. Combining apple cider vinegar with prescription diuretics like furosemide or hydrochlorothiazide could compound the potassium-lowering effect of both. The same concern applies to heart medications like digoxin, where low potassium increases the risk of toxic side effects. ACE inhibitors and ARBs, commonly prescribed for blood pressure, also interact with potassium balance in ways that apple cider vinegar can complicate.
What Apple Cider Vinegar Does Affect
The strongest evidence for apple cider vinegar’s health effects centers on blood sugar. A 2025 meta-analysis in Frontiers in Nutrition found that it significantly reduced long-term blood sugar markers in people with type 2 diabetes. The effect was meaningful enough to show up across multiple controlled trials, though the optimal dose remains uncertain.
For kidney health, the animal research on citrate excretion is promising for stone prevention, and the APUL trial was designed to test whether this translates to humans. But these effects relate to urine chemistry, not urine volume.
People with chronic kidney disease should be cautious. The extra acid load from vinegar can be difficult for compromised kidneys to process, according to UChicago Medicine.
Safe Amounts for Daily Use
Most studies showing benefits used 1 to 2 tablespoons per day, diluted in a large glass of water. Northwestern Medicine recommends sticking to that range and always diluting it to reduce irritation to your throat and stomach lining. Drinking it straight or in large quantities is where the risks start to climb, particularly for potassium depletion and digestive damage.
If you’re using apple cider vinegar hoping for a diuretic effect, you’d get more reliable results simply by drinking more water throughout the day. If you’re dealing with fluid retention, that’s a symptom worth investigating with a healthcare provider rather than managing with vinegar.