What Are the Benefits of Apple Cider Vinegar? What the Trials Found

The best-supported benefit of apple cider vinegar is a smaller rise in blood glucose after a carbohydrate meal, when the vinegar is taken with that meal: across the acute meal studies, the post-meal glucose response was lower by a moderate standardised margin of 0.60.¹ The second is a modest effect on weight: in one 12-week trial, 155 obese adults drinking 15 or 30 mL a day weighed about 1.2 kg and 1.9 kg less at 12 weeks, while the placebo group gained 0.4 kg.² Blood pressure and thrush claims have no adequate human trial behind them; for cholesterol, nine pooled trials found total cholesterol about 0.16 mmol/L lower;⁵ the GB register has no authorised claim for apple cider vinegar.¹⁶

Sources checked on 2 November 2026.

• Glucose: a blunted rise after a meal, by slowing stomach emptying; take it with the meal, diluted
• Weight: about 1 to 2 kg over 12 weeks at 15 to 30 mL a day in one trial; the widely quoted 2024 trial was retracted
• Safety: dilute it, take it with food, rinse; tell your diabetes team if you take glucose-lowering medicines

What is apple cider vinegar?

Apple juice fermented twice: yeasts turn its sugar into alcohol, then acetic acid bacteria turn the alcohol into acetic acid. A standard bottle is about 5% acetic acid, so a tablespoon (15 mL) carries about 750 mg.² "The mother" is the cloudy mat left in unfiltered vinegar; no trial has compared vinegar with and without it. The acetic acid is the active part.

Does apple cider vinegar lower blood sugar after meals?

It lowers the rise, when taken with the meal. The 2017 meta-analysis of acute studies found the post-meal glucose response reduced by a standardised 0.60 and the insulin response by 1.30 when vinegar was drunk with a carbohydrate meal.¹ The mechanism: vinegar slows stomach emptying, so glucose arrives in the blood more slowly. That is why people with gastroparesis, delayed stomach emptying, should not use it without advice; in a small study it slowed their emptying further.⁴ Pooled across nine trials of two weeks or more, fasting glucose fell by about 0.4 mmol/L and HbA1c by about 0.5 percentage points, the fasting glucose effect holding in trials longer than eight weeks; in apparently healthy people fasting glucose and HDL appeared to rise.⁵ The register's blood-glucose wording belongs to chromium, not vinegar; what chromium does for blood sugar explains.

Do glucose spikes matter if you are not diabetic?

Less than the glucose-monitor conversation suggests. The measures that predict future risk are an HbA1c, a fasting glucose and a GP's assessment.⁶ With prediabetes or type 2 diabetes, the NHS guidance on food, weight and activity is the evidence-backed route; vinegar is at most a small addition.⁶

Does apple cider vinegar help with weight or belly fat?

By a little. In 2009, 155 obese Japanese adults drank 15 or 30 mL of apple vinegar a day in a 500 mL drink for 12 weeks; body weight fell by about 1.2 kg on 15 mL and 1.9 kg on 30 mL while the placebo group gained 0.4 kg, with waist, visceral fat area and triglycerides lower than placebo too.² A 2025 meta-analysis of 10 trials in 789 adults put the pooled weight effect at a standardised 0.39, significant only in the trials giving 30 mL a day; that pooling includes the retracted Lebanese trial described below, which the review's authors rated low risk of bias, so the figure leans on data that have since been withdrawn.^{3, 7} A 2026 umbrella review of vinegar trials that does not include it put the difference at about 1 kg (1.06 kg across 12 trials and 918 adults, vinegars of all types, up to 12 weeks).¹⁷ The 2024 trial from Lebanon that reported much larger changes from 5 to 15 mL a day was retracted in September 2025 after its data proved unreliable, and its figures should not be repeated.⁷ The GB register rejected the apple cider vinegar weight claim,¹⁶ so no vinegar product in Britain may say it helps with weight; "belly fat" here means the visceral fat area measured in the Japanese trial.

Should you take apple cider vinegar in the morning or at night?

With a meal, because the meal is the mechanism. No trial has compared morning with night. In four small crossover trials of 9 to 10 adults each, two teaspoons of vinegar cut the post-meal glucose rise by about a fifth when taken with a bagel-and-juice meal, with less effect when taken five hours before it and none with a glucose drink, so the timing that matters is the meal itself.¹⁸ The post-meal glucose studies gave vinegar with the carbohydrate, and one small study in adults with well-controlled type 2 diabetes found that two tablespoons at bedtime with a snack moderated the next morning's fasting glucose; an empty stomach first thing has no evidence behind it and puts the most acid on your teeth.⁸ The routine: 15 to 30 mL in a large glass of water with a meal, then rinse; never neat.

Is it safe to drink apple cider vinegar every day?

At 15 to 30 mL diluted, the 2020 systematic review of 13 human studies judged the risk of side effects at recommended amounts small.⁹ Vinegar has a pH around 3 and in laboratory tests dissolved measurable mineral from human enamel, so sipping it neat through the day is the problem.¹⁰ The one human measurement points the same way: adults who drank two tablespoons of vinegar in a cup of water twice a day for eight weeks showed an 18% rise in a tooth-wear score, while the comparison group on a low-dose vinegar pill (45 mg of acetic acid against the drink's 3,600 mg a day) showed no change.¹⁹ UK dental guidance lists vinegar-based foods among the dietary acids to limit if taken often, advises keeping acidic drinks to mealtimes, and says not to swill or hold them in the mouth; a wide-bore straw is professional advice with weak evidence behind it.²⁰ Undiluted vinegar or a tablet lodged in the throat can burn the oesophagus; the published case came from a tablet.¹¹ At the extreme, a patient who drank large amounts daily developed low potassium and osteoporosis: a case report about excess, not a tablespoon.¹²

What medicines should not be taken with apple cider vinegar?

Four groups should ask first. Glucose-lowering medicines, insulin, gliclazide, glimepiride and metformin, because vinegar's post-meal effect adds to theirs; tell the diabetes team and check your meter. GLP-1 medicines such as semaglutide and tirzepatide slow digestion so that you feel fuller for longer, and vinegar slows stomach emptying too; no trial has tested the two together, so anyone on one should ask their prescriber or pharmacist before taking vinegar daily.^{4, 21, 22} Diuretics and digoxin, because of the potassium case above, which applies to heavy daily intake. And levothyroxine, where the issue is timing: there is no evidence that vinegar helps or hinders its absorption, and the NHS instruction is to take levothyroxine on an empty stomach 30 to 60 minutes before breakfast, caffeinated drinks or other medicines, so vinegar with a later meal is already separate.¹³

What about apple cider vinegar gummies?

A gummy is a measured dose of dried vinegar without the acid on your teeth, and its claims belong to its nutrients. Chromium contributes to the maintenance of normal blood glucose levels, the liquid trials above used 15 to 30 mL a day, and a vinegar powder's acetic acid is not stated on labels, so the formats are described, not ranked. What do apple cider vinegar gummies do has the detail and does apple cider vinegar improve gut health covers digestion and reflux.

What we don't know

The 2020 systematic review of 13 human studies judged the evidence for any health effect insufficient, and no trial has compared vinegar with and without the mother or one vinegar with another.⁹ The weight trials ran 4 to 12 weeks, the largest by a vinegar maker, and in the one that followed up, four weeks after stopping the 15 mL group was back at its starting weight and the 30 mL group within 0.4 kg of it, the authors' reading being that the effect lasts only as long as the vinegar is taken.^{2, 3} Whether a smaller post-meal glucose rise in people without diabetes changes any long-term outcome is untested.⁵

Frequently asked questions

Does apple cider vinegar lower blood pressure?

No good human evidence. The blood-pressure finding comes from rats fed acetic acid; the pooled human trials measured glucose and lipids.^{5, 14}

Does apple cider vinegar lower cholesterol?

Across nine trials, total cholesterol was about 0.16 mmol/L lower with vinegar, with no change in LDL or HDL: a number, not a claim.⁵

Can I take apple cider vinegar when pregnant or breastfeeding?

In food amounts, yes. There are no studies of daily supplement-style doses in pregnancy; keep to a diluted splash with meals and ask your midwife. Vinegar gummies have no pregnancy trial either; what do apple cider vinegar gummies do covers them, including the ginger variety.

Can I drink apple cider vinegar with PCOS?

Yes in food amounts; the post-meal glucose effect is the main finding, and in one 2026 trial of 94 women with PCOS (now called PMOS by the NHS) on metformin, metabolic syndrome resolved more often on vinegar capsules (1,500 mg of powder a day, stated by the makers as 1,050 mg of acetic acid) than on placebo.¹⁵ If you take metformin, the glucose-lowering caution above applies.

Which vinegar is healthiest?

None has a trial showing it beats another; acetic acid is the active ingredient in each, and the weight trial used apple vinegar.² Fruit vinegars differ in their polyphenol content in the laboratory, but the few human trials of other fruit vinegars had no apple cider vinegar arm: 20 mL a day of a date vinegar for 10 weeks lowered HbA1c within the vinegar group in a placebo-controlled trial of 50 adults with type 2 diabetes, a persimmon vinegar raised a plasma antioxidant marker in 81 healthy adults, and no trial of pomegranate vinegar in people exists.^{23, 24, 25}

Sources

1. Shishehbor F, et al. Vinegar consumption can attenuate postprandial glucose and insulin responses. Diabetes Research and Clinical Practice, 2017. Meta-analysis of controlled meal studies; funding not stated on PubMed. PubMed 28292654.
2. Kondo T, et al. Vinegar intake reduces body weight, body fat mass, and serum triglyceride levels in obese Japanese subjects. Bioscience, Biotechnology, and Biochemistry, 2009. Randomised trial, 175 obese adults randomised, 155 completed, 12 weeks; all authors employed by a vinegar manufacturer. PubMed 19661687.
3. Castagna A, et al. Effect of apple cider vinegar intake on body composition in humans with type 2 diabetes and/or overweight. Nutrients, 2025. Meta-analysis, 10 randomised trials, 789 adults; includes the retracted 2024 Lebanese trial (its reference 44), which the review rated low risk of bias; no external funding, no conflicts declared. PubMed 41010525.
4. Hlebowicz J, et al. Effect of apple cider vinegar on delayed gastric emptying in patients with type 1 diabetes mellitus. BMC Gastroenterology, 2007. Crossover pilot, 10 adults with type 1 diabetes and gastroparesis; funded by grants from the Malmö Diabetes Association (full text). PubMed 18093343.
5. Hadi A, et al. The effect of apple cider vinegar on lipid profiles and glycemic parameters. BMC Complementary Medicine and Therapies, 2021. Meta-analysis, 9 trials of two weeks or more; no conflicts declared. PubMed 34187442.
6. NHS. Type 2 diabetes: food and keeping active. nhs.uk. Page last reviewed 10 February 2025. Read 30 October 2026.
7. Retraction: Apple cider vinegar for weight management in Lebanese adolescents and young adults with overweight and obesity. BMJ Nutrition, Prevention & Health, 2025. Retraction notice. PubMed 41789013.
8. White AM, Johnston CS. Vinegar ingestion at bedtime moderates waking glucose concentrations in adults with well-controlled type 2 diabetes. Diabetes Care, 2007. Crossover pilot, 11 adults with type 2 diabetes; funding not stated on PubMed. PubMed 17712024.
9. Launholt TL, et al. Safety and side effects of apple vinegar intake and its effect on metabolic parameters and body weight. European Journal of Nutrition, 2020. Systematic review, 13 human studies; funding not stated on PubMed. PubMed 32170375.
10. Willershausen I, et al. In vitro study on dental erosion caused by different vinegar varieties using an electron microprobe. Clinical Laboratory, 2014. Laboratory study on human enamel. PubMed 24839821.
11. Hill LL, et al. Esophageal injury by apple cider vinegar tablets and subsequent evaluation of products. Journal of the American Dietetic Association, 2005. Case report and test of 8 tablet products. PubMed 15983536.
12. Lhotta K, et al. Hypokalemia, hyperreninemia and osteoporosis in a patient ingesting large amounts of cider vinegar. Nephron, 1998. Case report. PubMed 9736833.
13. NHS. Levothyroxine. nhs.uk. Page last reviewed 6 July 2026. Read 30 October 2026.
14. Kondo S, et al. Antihypertensive effects of acetic acid and vinegar on spontaneously hypertensive rats. Bioscience, Biotechnology, and Biochemistry, 2001. Rat study; authors employed by a vinegar manufacturer. PubMed 11826965.
15. Najafi A, et al. Scientific Reports, 2026. Randomised trial, 94 women with PCOS on metformin, 1,500 mg of vinegar powder a day in three capsules, stated as 1,050 mg acetic acid, for 12 weeks; no competing interests declared. PubMed 42215584.
16. Great Britain nutrition and health claims (NHC) register: apple cider vinegar entries, all non-authorised. gov.uk. Page last updated 19 May 2026. Read 30 October 2026.
17. Shahmohammadi F, et al. Vinegar consumption and health: an umbrella review of meta-analyses of randomised controlled trials. Food Science & Nutrition, 2026. Umbrella review, 10 meta-analyses and 38 trials; weight pooling 12 trials, 918 adults, mean difference 1.06 kg; funded by a university students' research centre in Tehran; no conflicts declared. PubMed 42110393.
18. Johnston CS, et al. Examination of the antiglycemic properties of vinegar in healthy adults. Annals of Nutrition & Metabolism, 2010. Four randomised crossover trials, 9 to 10 adults each, one in type 2 diabetes; research support from a source other than the US government listed on PubMed, funder not named. PubMed 20068289.
19. Anderson S, et al. Evidence that daily vinegar ingestion may contribute to erosive tooth wear in adults. Journal of Medicinal Food, 2021. Tooth-wear sub-study of an 8-week randomised trial, a twice-daily vinegar drink (3.6 g acetic acid) against a vinegar pill (0.045 g); participant number not in the abstract; funding not stated on PubMed. PubMed 33297831.
20. Office for Health Improvement and Disparities. Delivering better oral health: an evidence-based toolkit for prevention, chapter 7, tooth wear. gov.uk. Updated 10 September 2025. Read 2 November 2026.
21. NHS. Semaglutide. nhs.uk. Page last reviewed 15 May 2026. Read 2 November 2026.
22. NHS. Tirzepatide. nhs.uk. Page last reviewed 15 May 2026. Read 2 November 2026.
23. Ali Z, et al. Clinical and computational exploration of red date fruit vinegar: synergistic effects on cardiovascular and type 2 diabetes pathways. Frontiers in Nutrition, 2025. Randomised placebo-controlled trial, 50 adults with type 2 diabetes and dyslipidaemia, 25 per group, 20 mL of date vinegar a day for 10 weeks, with computational work; university funding; no commercial conflicts declared. PubMed 40727700.
24. Mure K, et al. Effects of kakisu (persimmon vinegar) on plasma antioxidant power and urinary 8-isoprostane level. Nihon Eiseigaku Zasshi, 2007 (Japanese, English abstract). Randomised crossover trial, 81 healthy adults aged 30 to 69, about eight weeks of vinegar in each period; funding not stated on PubMed. PubMed 17334090.
25. Erim B, Binici HI. Comparative analysis of phenolic content and antioxidant capacities of various vinegar types. Journal of Oleo Science, 2025. Laboratory analysis of six plant vinegars; funding not stated on PubMed. PubMed 40887266.

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This article is general information, not medical advice. If you take glucose-lowering medicines, a GLP-1 medicine, diuretics or digoxin, have gastroparesis, or are pregnant or breastfeeding, ask your diabetes team, pharmacist or midwife before taking apple cider vinegar daily, and never change a prescribed medicine on the strength of it.