Most people benefit from 1 to 2 tablespoons (15 to 30 mL) of apple cider vinegar per day, diluted in water. That range is where the clinical evidence clusters, and it’s also the upper limit of what experts consider safe for daily use. Going beyond 2 tablespoons increases the risk of side effects without clear additional benefit.
The Dosages Studied in Clinical Trials
A 2024 study published in BMJ Nutrition tested three doses: 5 mL (about 1 teaspoon), 10 mL (about 2 teaspoons), and 15 mL (1 tablespoon) of apple cider vinegar diluted in a cup of water, taken once daily for 12 weeks. All three doses led to significant reductions in body weight, BMI, and waist circumference compared to placebo. The effects were dose-dependent, meaning the 15 mL group saw the largest changes, losing roughly 6 to 8 kg (13 to 18 pounds) over the 12-week period. That same group also had the greatest improvements in blood sugar, triglycerides, and total cholesterol.
For blood sugar specifically, research on post-meal glucose spikes has used doses closer to 4 teaspoons (20 mL), taken right before eating. That amount has been shown to meaningfully blunt the rise in blood sugar after a carb-heavy meal. So while even small amounts appear to do something, 1 to 2 tablespoons is the practical sweet spot backed by human studies.
When to Drink It
Timing depends on your goal. If you’re trying to manage blood sugar, taking your diluted vinegar immediately before a meal is the best-supported approach. The acetic acid slows the rate at which food leaves your stomach, which flattens the post-meal glucose curve. The BMJ weight loss study had participants drink it in the morning on an empty stomach, but other experts caution that vinegar on an empty stomach can trigger nausea or indigestion. If you notice stomach discomfort, shift your dose to just before your largest meal instead.
How to Dilute It Safely
Never drink apple cider vinegar straight. Undiluted, it’s acidic enough to erode tooth enamel and damage the lining of your esophagus. The standard recommendation from MD Anderson Cancer Center is no more than 1 tablespoon mixed into at least 8 ounces of water, tea, or another liquid.
The American Dental Association goes a step further, recommending you drink it through a straw to minimize contact with your teeth, swish plain water in your mouth afterward, and wait at least one hour before brushing. Brushing too soon after exposure to acid can actually scrub away softened enamel.
The Upper Limit
Exceeding 2 tablespoons per day is where the risk profile changes. At higher doses, apple cider vinegar can irritate the esophagus, accelerate enamel erosion, and, most importantly, lower your potassium levels. Low potassium causes muscle cramps, weakness, nausea, constipation, and in more serious cases, abnormal heart rhythms. This potassium issue becomes especially dangerous if you’re also taking medications that deplete potassium, including common water pills (diuretics) like hydrochlorothiazide or furosemide.
Other medication interactions worth knowing about: if you take insulin or other diabetes medications, adding apple cider vinegar can push blood sugar too low, since both are working to reduce glucose at the same time. And if you take digoxin for heart conditions, the potassium drop from regular vinegar consumption can amplify that drug’s side effects. If any of these apply to you, talk to your pharmacist or prescriber before adding a daily vinegar habit.
What About Gummies and Capsules?
ACV gummies have become popular, but they’re not equivalent to the liquid form. A typical gummy contains about 500 mg of apple cider vinegar powder, which is a tiny fraction of the 15 to 30 mL doses used in clinical studies. The research that showed benefits for weight, blood sugar, and cholesterol all used liquid vinegar containing about 5% acetic acid, which is the standard concentration for commercial apple cider vinegar sold in the U.S. (the FDA requires at least 4% acetic acid for any product labeled as vinegar). There’s currently no published evidence that gummies at their typical doses produce the same effects.
Does It Help With Heartburn?
This is one of the most popular uses you’ll find recommended online, but it has zero published clinical evidence behind it. Harvard Health Publishing reviewed the claim and found no studies in medical journals supporting apple cider vinegar as a treatment for heartburn or acid reflux. The theory is that adding acid to the stomach might tighten the valve that prevents reflux, but that valve is controlled by a complex system of muscles, hormones, and nerve signals, not just stomach acidity. Given that vinegar is itself highly acidic, there’s a real chance it could make reflux worse rather than better.
A Practical Starting Routine
If you’re new to apple cider vinegar, start with 1 teaspoon in a full glass of water before your largest meal. This lets you gauge how your stomach handles it. Over a week or two, you can increase to 1 tablespoon, and eventually to 2 tablespoons if you tolerate it well. Use a straw, rinse your mouth with plain water when you’re done, and don’t brush your teeth for at least an hour afterward.
Choose a liquid product labeled as containing 5% acetic acid, ideally one with “the mother,” which is the cloudy strand of proteins and bacteria visible in unfiltered versions. While the mother hasn’t been independently proven to add health benefits beyond the acetic acid itself, it indicates the vinegar hasn’t been overly processed. Store it at room temperature, and keep in mind that the taste doesn’t improve with higher doses. Mixing it into herbal tea or adding a small amount of honey can make the daily routine more tolerable.