Quick Answer: Apple cider vinegar has one benefit with reasonable evidence behind it: taken with a carbohydrate meal, it modestly blunts the blood glucose and insulin rise afterwards.
Pooled analyses of randomised trials also show small average improvements in fasting glucose, HbA1c, total cholesterol, body weight and systolic blood pressure at doses of roughly 15 to 30 ml a day. Everything else attributed to it detoxing, curing acne, dissolving kidney stones, treating reflux is unsupported. It also carries documented harms that most articles skip: tooth enamel erosion, oesophageal injury, chemical burns from undiluted use, and dangerously low potassium at high intakes.
Nutritionally it is close to nothing: one tablespoon is about 3 calories, 0.1 g carbohydrate, 1 mg sodium and 11 mg potassium, with no fat, protein, fibre or vitamins. Whatever ACV does, it does through acetic acid, and every vinegar contains that.
What Apple Cider Vinegar Is
Two fermentations. Yeast converts the sugars in apple juice to alcohol, then acetic acid bacteria convert that alcohol to acetic acid. Finished cider vinegar is roughly 5 to 6 percent acetic acid.
“The mother” is the cloudy sediment of bacteria and cellulose in raw, unfiltered ACV. It is often sold as the part that matters. There is no good evidence that it confers benefits, and it carries a small risk the filtered version does not: unpasteurised apple products, including raw ACV, have been implicated in E. coli outbreaks. If you are pregnant, immunocompromised, elderly or buying for a child, the pasteurised bottle is the safer one.
What the Evidence Actually Supports
Post-meal blood glucose: the strongest finding
A systematic review and meta-analysis of clinical trials published in Diabetes Research and Clinical Practice concluded that vinegar consumption attenuates postprandial glucose and insulin responses. The proposed mechanisms are slowed gastric emptying and interference with the enzymes that break down starch.
A 2026 umbrella review of meta-analyses of randomised trials, published in Food Science and Nutrition, found pooled improvements at doses of roughly 15 to 30 ml a day:
| Outcome | Pooled average change |
|---|---|
| Fasting blood glucose | about −9.4 mg/dL |
| Postprandial glucose | about −14.6 mg/dL |
| HbA1c | about −0.70% |
| Total cholesterol | about −9.4 mg/dL |
| Body weight | about −1.06 kg |
| Systolic blood pressure | about −2.9 mmHg |
Those are real but modest effects, drawn from trials that are mostly under 12 weeks with small samples. A weight change of around one kilogram is not a weight-loss strategy. An HbA1c shift is not a substitute for diabetes treatment. Apple cider vinegar is an adjunct at best, and it does not replace medication or dietary management.
Satiety and calorie intake
Some small studies report increased fullness after vinegar with a high-carbohydrate meal, with knock-on reductions in intake later in the day. This is frequently repeated as a precise figure of “200 to 275 fewer calories,” which comes from one small study and should not be treated as a reliable number. The nausea that vinegar can cause may account for part of the effect.
Antimicrobial activity
Vinegar inhibits bacterial growth, which is why it has been used as a food preservative for millennia. That is a genuine property, demonstrated on surfaces and in food. It does not follow that drinking it treats infections in your body, and it is not a reason to use it on wounds.
ACV Tablets and Gummies: The Dose Problem
This is the single most useful thing on this page if you are considering buying a supplement, and it is the reason the pills sold alongside the liquid are a poor bet.
Two tablespoons of liquid ACV deliver roughly 1,400 mg of acetic acid. A typical ACV tablet contains about 15 mg. That is around one percent of the dose used in the trials.
A review in the Journal of Primary Health Care sets out what that means in practice. In people with type 2 diabetes over 12 weeks, two tablespoons of liquid ACV twice daily produced a 0.16 percent reduction in HbA1c. The group taking an ACV tablet containing 15 mg of acetic acid showed a 0.06 percent increase. The tablets did not work, and the arithmetic explains why.
Two further problems with the supplement form:
- Content is not standardised. Vinegar products sold for medicinal purposes are neither regulated nor standardised as medicines, and analyses have found they vary widely in acetic acid content and pH. You cannot know what is in the bottle.
- Tablets can lodge and burn. A published case describes oesophageal injury in a 48-year-old woman after an ACV tablet became stuck in her throat. The acid then acts on the oesophageal lining rather than being diluted in the stomach.
If you want the effect the research describes, it comes from diluted liquid taken with food, not from a capsule or a gummy.
Documented Harms
ACV is not risk-free, and the risks scale with how concentrated and how frequent the exposure is. These are documented in the clinical literature, not hypothetical.
- Tooth enamel erosion. In an eight-week controlled study, adults taking vinegar daily showed an 18 percent increase in erosive tooth wear scores while the control group showed no change. This is the most likely harm for anyone taking a daily ACV drink.
- Low potassium, and cardiac arrest at the extreme. A case report describes hypokalaemia, hyperreninaemia and osteoporosis in a 28-year-old woman consuming large amounts of cider vinegar over a long period. A separate report describes two cases of cardiac arrest attributed to cider-vinegar-induced hypokalaemia. These involved heavy, sustained intake, not a tablespoon in a salad dressing, but they set the outer boundary.
- Oesophageal and throat irritation. Undiluted vinegar can burn the throat and oesophagus. Never drink it neat.
- Chemical burns on skin. Topical application of undiluted ACV has caused chemical burns, including in children. There are published case reports.
- Worsened gastroparesis. A study in people with type 1 diabetes found ACV further reduced an already delayed gastric emptying rate, which the authors noted may be a disadvantage for glycaemic control. If you have gastroparesis, ACV is likely to make it worse rather than better.
- Reflux. ACV is sometimes recommended for heartburn. There is no evidence it helps, and acid on an already irritated oesophagus is a plausible way to make symptoms worse.
Who Should Avoid It, and Drug Interactions
- Anyone on insulin or glucose-lowering medication. ACV lowers blood glucose, so combining it with medication that does the same carries a hypoglycaemia risk. Speak to your prescriber before adding it regularly.
- Anyone on diuretics, digoxin, laxatives or other potassium-lowering medicines. The effects are potentially additive, and low potassium is the mechanism behind the most serious reported harms.
- Diabetic gastroparesis. See above.
- Pregnancy and breastfeeding. Regular medicinal use is not recommended, on the grounds of insufficient evidence rather than proven harm.
- Apple or pectin allergy. Avoid.
- Existing dental erosion, reflux or chronic kidney disease. Discuss with your clinician first.
One more, and it matters: ACV is promoted in some places as an alternative treatment for skin cancer. It is not a cancer treatment, and using it in place of medical care is dangerous.
Claims That Do Not Hold Up
| Claim | Where it stands |
|---|---|
| Detoxifies the body, supports liver function, eliminates toxins | Not supported. The liver and kidneys clear metabolic waste continuously and no food improves on that. “Detox” is marketing, not physiology. |
| Cures acne | Not supported. Undiluted application can burn skin. |
| Improves eczema | Evidence points the other way. A study in 22 people with eczema found ACV soaks did not improve the skin barrier and caused irritation. |
| Dissolves kidney stones | Not supported. There is no evidence ACV dissolves calcium oxalate stones, and kidney stones need medical assessment. |
| Treats acid reflux | Not supported, and plausibly counterproductive. |
| Provides probiotics via “the mother” | Not supported. No trial has shown a probiotic benefit, and raw unpasteurised products carry their own risk. |
| Cures dandruff or promotes hair growth | Not supported. It may remove product buildup, which is a cosmetic effect. |
| Boosts immunity | Not supported. |
| Use as a vaginal or “feminine” wash | Actively discouraged. There is no evidence for it, and acidic washes can disrupt vaginal flora and cause irritation or infection. Earlier versions of this page carried a recipe for this. It has been removed, and we would not recommend anyone try it. |
| Heart health benefits | Partly. Pooled human data show a small reduction in total cholesterol and systolic blood pressure. The stronger lipid claims come from animal studies that have not been replicated in people. |
How to Use It Sensibly
- Always dilute. One to two tablespoons in a large glass of water. Never neat, never as a “shot”.
- Take it with a meal, not on an empty stomach. The glucose effect is a meal effect, and food buffers the acid.
- Protect your teeth. Drink through a straw, rinse your mouth with plain water afterwards, and do not brush immediately brushing softened enamel makes erosion worse.
- Stay at or below one to two tablespoons a day. More does not produce more benefit and does raise the risk of the harms above.
- Use it as food. Salad dressings, marinades and slaws give you the acetic acid with none of the neat-vinegar risk, and they taste better.
- Skip the pills and gummies. See the dose section above.
- Do not put it on broken skin, and do not use it internally anywhere other than your mouth.
Adding honey or lemon changes the flavour, not the pharmacology. Honey adds sugar, which is worth knowing if the reason you are drinking this is blood glucose. Our guide to reading nutrition labels covers how added sugars are declared.
Why You Should Take Apple Cider Vinegar
Frequently Asked Questions
One thing has reasonable evidence: taken with a carbohydrate meal, vinegar modestly blunts the blood glucose and insulin rise afterwards. A 2026 umbrella review of meta-analyses also found small pooled improvements in fasting glucose, HbA1c, total cholesterol, body weight of about one kilogram, and systolic blood pressure, at doses of 15 to 30 ml a day. These effects are modest and come from mostly short, small trials. Claims about detoxing, curing acne, dissolving kidney stones and treating reflux are not supported.
The dose makes them unlikely to. Two tablespoons of liquid ACV contain roughly 1,400 mg of acetic acid; a typical ACV tablet contains about 15 mg, around one percent of that. In a 12-week trial in type 2 diabetes, two tablespoons of liquid twice daily reduced HbA1c by 0.16 percent while the 15 mg tablet group showed a 0.06 percent increase. Supplement content is also unregulated and varies widely in acetic acid and pH, and a published case describes oesophageal injury after an ACV tablet lodged in a woman’s throat.
One to two tablespoons diluted in a large glass of water, taken with a meal, is the range used in most research and is generally safe for healthy adults. More does not produce more benefit and does increase risk. Never drink it undiluted, and drink through a straw and rinse with water afterwards to protect tooth enamel. If you take glucose-lowering or potassium-lowering medication, speak to your prescriber before making it a daily habit.
Yes, and this is the most likely harm from regular use. Vinegar is acidic enough to dissolve tooth enamel. In an eight-week controlled study, adults taking vinegar daily showed an 18 percent increase in erosive tooth wear scores while the control group showed none. Dilute it, drink through a straw, rinse with plain water afterwards, and avoid brushing immediately, since brushing softened enamel makes the erosion worse.
Anyone on insulin or other glucose-lowering medication, because of hypoglycaemia risk; anyone on diuretics, digoxin, laxatives or other potassium-lowering medicines, because the effects may be additive; people with diabetic gastroparesis, since ACV further delays gastric emptying; people with an apple or pectin allergy; and anyone with existing dental erosion, reflux or chronic kidney disease without speaking to a clinician. Regular medicinal use is not recommended in pregnancy or breastfeeding due to insufficient evidence.
Only marginally. Pooled analyses of randomised trials show an average weight difference of around one kilogram, at doses above typical culinary use and over short study periods. Some small studies report increased fullness after vinegar with a high-carbohydrate meal. The frequently quoted figure of 200 to 275 fewer calories a day comes from a single small study and should not be treated as reliable. ACV is not a weight-loss treatment.
There is no good evidence that it is. The mother is the cloudy sediment of bacteria and cellulose in raw unfiltered ACV, and no trial has demonstrated a probiotic or other benefit from it. It also carries a small risk the pasteurised version does not, since unpasteurised apple products including raw ACV have been implicated in E. coli outbreaks. Pregnant women, immunocompromised people, older adults and children are better served by the pasteurised bottle.
Not safely. Undiluted ACV has caused chemical burns on skin, including in children, and a study in 22 people with eczema found ACV soaks did not improve the skin barrier and caused irritation. Using it as a vaginal or feminine wash has no evidence behind it and can disrupt vaginal flora, causing irritation or infection. Speak to a healthcare provider about any vaginal health concern rather than using a home remedy.
Probably not. The active compound in the research is acetic acid, and every vinegar contains it at broadly similar concentrations, around 5 to 6 percent. Much of the underlying research used white or generic vinegar rather than apple cider vinegar specifically. There is no demonstrated advantage to the apple variety beyond taste.
Related Reading
- Balsamic vinegar nutrition facts and what the evidence says
- How to spot a fad diet: red flags and the real evidence
- How to read nutrition labels to make smarter food choices
- Kiwi fruit benefits: nutrition, real evidence and side effects
Sources
- Memorial Sloan Kettering Cancer Center, Apple Cider Vinegar, summarising the evidence and the documented adverse events.
- Apple cider vinegar, Journal of Primary Health Care, on dosing, the acetic acid content of tablets versus liquid, interactions and cautions.
- Shishehbor, Mansoori and Shirani, Vinegar consumption can attenuate postprandial glucose and insulin responses, Diabetes Research and Clinical Practice, 2017.
- Vinegar Consumption and Health: An Umbrella Review of Meta-Analyses of Randomized Controlled Trials, Food Science and Nutrition, 2026.
- Hill et al., Esophageal injury by apple cider vinegar tablets and subsequent evaluation of products.
- Anderson, Gonzalez, Jasbi and Johnston, Evidence That Daily Vinegar Ingestion May Contribute to Erosive Tooth Wear in Adults, Journal of Medicinal Food, 2021.
- USDA FoodData Central, for apple cider vinegar nutrient values.
Last reviewed and rewritten September 2026. This article is general information, not medical advice, and apple cider vinegar is not a treatment for any condition. Do not stop or change prescribed medication on the basis of anything you read here. If you take insulin or other glucose-lowering medication, diuretics, digoxin or other potassium-affecting drugs, have diabetes, gastroparesis, reflux, chronic kidney disease or dental erosion, or you are pregnant or breastfeeding, speak to your doctor, pharmacist or dentist before using apple cider vinegar regularly. Never apply undiluted vinegar to skin, and never use it internally other than diluted by mouth. How we research and check this content is described in our editorial process and sources cited policy.
