Does Apple Cider Vinegar Help With Weight Loss? What the Trials Found

By a little, over 4 to 12 weeks, in trials of adults with overweight, obesity or type 2 diabetes: in the largest trial built to measure weight, 155 obese Japanese adults drinking 15 or 30 mL of apple vinegar a day weighed about 1.2 kg and 1.9 kg less at 12 weeks while the placebo group gained 0.4 kg, and a 2026 umbrella review of 12 vinegar trials in 918 adults put the pooled difference at about 1 kg.^{1, 2} The widely quoted 2024 trial from Lebanon that reported far larger changes was retracted in September 2025, one 2025 pooled estimate still contains it, and the GB register lists the apple cider vinegar weight claim as non-authorised, so no vinegar product in Britain may say it helps with weight.^{3, 4, 5} What follows is the trial record, stated as numbers.

Sources checked on 2 November 2026.

• The 12-week trial: about 1.2 kg at 15 mL a day and 1.9 kg at 30 mL, against a 0.4 kg gain on placebo; weight back at or close to baseline four weeks after stopping
• Pooled: about 1 kg across 12 trials and 918 adults, vinegars of all types, up to 12 weeks; the 2025 pooling of 10 apple cider vinegar trials still includes the retracted study
• The law: "Helps control and normalize body weight" is a non-authorised claim in Great Britain, register entry 1380

What did the 12-week trial find?

In 2009, researchers employed by a vinegar maker randomised 175 Japanese adults aged 25 to 60 with a BMI of 25 to 30, otherwise healthy and taking no medicines, to a 500 mL daily drink containing 15 mL of apple vinegar (750 mg of acetic acid), 30 mL (1,500 mg) or none, taken as two 250 mL portions after breakfast and after supper for 12 weeks; 155 completed.¹ Body weight went from 74.9 to 73.7 kg on 15 mL, from 73.1 to 71.2 kg on 30 mL, and from 74.2 to 74.6 kg on placebo, with the difference from placebo significant from week 4 and the higher dose ahead of the lower from week 8. Triglycerides were lower in both vinegar groups too, and diet diaries and step counts did not differ between the groups. Four weeks after the drinks stopped, the 15 mL group was back at its starting weight and the 30 mL group within 0.4 kg of it, and the authors conclude that the effect lasts only as long as the intake does.¹ Every author worked for the company that makes the vinegar: the numbers stand, and the funding position stands beside them.

Which trials have measured weight on apple cider vinegar?

Ten randomised trials of apple cider vinegar lasting four weeks or more had reported weight or BMI by March 2025, according to the 2025 review that pooled them: eight in Asia, one in Tunisia and one in Lebanon, none in Europe.³ Standard vinegar is about 5% acetic acid, so 15 mL carries about 750 mg and 30 mL about 1,500 mg; the Japanese trial states the acetic acid in its drink, and most of the others give millilitres only.^{1, 3}

The 2026 umbrella review pooled weight from 12 trials of vinegars of all types: six shared with the 2025 review, six it did not include, and none of the four the 2025 review pooled alone, the retracted trial among them.^{2, 3} Funding is stated for few of the ten: the Japanese trial's authors were employed by a vinegar maker, the Lebanese trial's record declares no competing interests, the 2023 Iranian trial declares no commercial or financial relationships, and the 2025 review's table carries no funding column, so for most of the rest the question is open.^{1, 3, 4, 12}

What do the pooled estimates say, and which include the retracted trial?

Two poolings, agreeing on size and differing on what went in. The 2025 meta-analysis of 10 apple cider vinegar trials in 789 adults found body weight lower by a standardised 0.39, BMI by 0.65 and waist by 0.34; weight reached significance only in the trials giving 30 mL a day (a standardised 0.60), not at 5 to 15 mL.³ The review also translates its standardised weight effect into about 7.4 kg, or 9.4% of starting body weight; that figure is a conversion from the standardised effect, not a measurement, and sits well above the 1.2 to 1.9 kg the Japanese trial measured at 12 weeks.^{1, 3} It includes the retracted Lebanese trial, which its authors rated one of only two trials at low risk of bias, and its sensitivity analysis removed only trials at high risk, so the retracted data stayed in its overall estimates; the 30 mL a day subgroup, the one weight estimate that reached significance by dose, does not contain it, because that trial gave 5 to 15 mL. The review declares no external funding and no conflicts.^{3, 4} The 2026 umbrella review, which re-pooled the trials behind ten earlier meta-analyses, does not include the Lebanese trial: across 12 trials and 918 adults, vinegars of all types, 1.5 to 60 mL a day for five days to 12 weeks, body weight was 1.06 kg lower than control (95% confidence interval 0.52 to 1.60 kg), with little variation between trials and a certainty of evidence the authors graded high; BMI and waist were not significantly different.² It was funded by a university students' research centre in Tehran.² The estimate that leaves the retracted trial out is about 1 kg, the size of the Japanese trial's lower dose, and it is the one to quote.

What about the retracted 2024 trial?

The trial recruited 120 Lebanese adolescents and young adults with overweight or obesity and gave them 5, 10 or 15 mL of apple cider vinegar in 250 mL of water, or a placebo drink, daily for 12 weeks, and reported reductions in weight, BMI, waist, body fat, glucose, triglycerides and cholesterol at every dose.⁴ In September 2025 the journal retracted it with the authors' agreement: the analyses could not be replicated, multiple errors were found, the dataset showed patterns inconsistent with random allocation to groups, and the p-values were improbably small for the number of participants; the journal also recorded that the trial had not been registered in advance.⁴ Its figures should not be repeated, and a pooled estimate that contains them leans on data that have been withdrawn.

Does apple cider vinegar reduce belly fat?

"Belly fat" has one direct measurement in the vinegar trials. The Japanese trial scanned the abdomen by CT at the level of the fourth and fifth lumbar vertebrae at weeks 0 and 12: visceral fat area fell by 2.8% on 15 mL and 4.9% on 30 mL while it rose 4.4% on placebo, and total abdominal fat area fell 2.8% and 3.5% against a 1.0% rise.¹ That is a measured change of a few per cent over 12 weeks in people with a BMI of 25 to 30, not a flat stomach. Waist tells the same story at a smaller scale: 1.4 to 1.9 cm from their starting values in the Japanese trial, and across the five vinegar trials the umbrella review could pool, 0.91 cm, which did not reach significance.^{1, 2} No food or supplement removes fat from one area in preference to another; what the trials show is a small whole-body change that shows up at the waist too.

Does apple cider vinegar suppress appetite or speed up metabolism?

Neither has a trial showing it. In two acute studies at the University of Surrey, 16 healthy young adults ate breakfast with vinegar in a palatable or an unpalatable drink, and 14 others tasted vinegar without swallowing it after a milkshake: swallowed vinegar did reduce appetite and intake, but the effect tracked nausea ratings and was largest with the worst-tasting drink, and tasting alone did nothing, so the authors concluded that promoting vinegar as a natural appetite suppressant "does not seem appropriate".⁷ On metabolism, 16 healthy adults who took 30 mL a day for four days showed no change in resting energy expenditure, in the energy used cycling, or in the mix of carbohydrate and fat burned.⁸ The mechanism that has been measured is slower stomach emptying, the reason vinegar with a carbohydrate meal blunts the glucose rise: in 10 people with type 1 diabetes and already slow emptying, 30 mL in water cut the median emptying rate from 27% to 17%.⁹ Whether slower emptying over 12 weeks accounts for a kilogram is not known; the trials measured the kilogram, not the route to it.

Why no vinegar product in Britain may say it helps with weight

Because the claim was assessed and not authorised. The Great Britain nutrition and health claims register lists the apple cider vinegar claim "Helps control and normalize body weight" as entry 1380, status "Non-authorised", with the reason that "on the basis of the scientific evidence assessed, this claimed effect for this food has not been substantiated", citing a 2011 scientific opinion; it remains non-authorised in the register's 19 May 2026 version.⁵ A food business in Great Britain therefore cannot make the weight claim on a label, in an advert or on a product page, for liquid vinegar or for a tablet, capsule or gummy made from it, whatever the trials above found; nine of the 12 trials in the 2026 pooling were published after the opinion the register cites.^{2, 5} What a product can carry are the authorised wordings of nutrients added to it, which is why a vinegar gummy's claims belong to its chromium or vitamin C and not to the vinegar; what do apple cider vinegar gummies do sets those out.

Do apple cider vinegar gummies, capsules or powders help with weight?

No weight trial has used a gummy or a powder. One capsule trial has run for weeks: in 2026, 94 women with polycystic ovary syndrome (PCOS, now called PMOS by the NHS) and metabolic syndrome, all starting metformin, took three capsules a day of 500 mg of apple cider vinegar powder, 1,500 mg in all and stated by the makers as 1,050 mg of acetic acid, about 20 to 22 mL of standard liquid vinegar, or placebo for 12 weeks.⁶ Weight was not its primary outcome: BMI fell from 27.8 to 26.8 on the capsules against 26.9 to 26.8 on placebo, a significant difference, while waist circumference did not differ between the groups, and metabolic syndrome resolved in 74.5% against 40.4%.⁶ A gummy's label gives the weight of vinegar powder and rarely an acetic acid figure, so it cannot be converted into the 15 to 30 mL the liquid trials used. What do apple cider vinegar gummies do covers what is in one and the small format trials.

How did the trials take it, and who should ask first?

Diluted and daily: 15 to 30 mL in 100 to 500 mL of water, with or after meals in the trials that say, for 4 to 12 weeks, never neat.^{1, 3} If you take a glucose-lowering medicine, tell your diabetes team before taking vinegar daily, because its effect on the post-meal glucose rise adds to the medicine's. What are the benefits of apple cider vinegar covers teeth, timing, the glucose effect and the medicines to ask about, including GLP-1 medicines, and does apple cider vinegar improve gut health covers reflux and digestion.

What we don't know

Whether apple cider vinegar changes weight in people who are not overweight and do not have type 2 diabetes: the 2025 review's ten trials all recruited one or the other, and the 2026 pooling's subgroups are the same two groups.^{2, 3} Whether anything persists after stopping, since the one trial that looked found weight back at or close to baseline within four weeks.¹ Whether the effect holds beyond 12 weeks, the longest any trial ran, or in a UK population, since none has been run here.^{2, 3}

Frequently asked questions

How long does apple cider vinegar take to work for weight?

Differences from placebo appeared from week 4 and were largest at week 12, the longest anyone has measured: about 1.2 kg at 15 mL and 1.9 kg at 30 mL in the Japanese trial, so around a third to two-thirds of a kilogram a month on average, inside most people's week-to-week water fluctuation.¹

Should I drink apple cider vinegar in the morning or at night for weight?

No weight trial compared timings. The Japanese trial gave its drink after breakfast and after supper, and the glucose studies gave vinegar with the carbohydrate meal; first thing on an empty stomach has no trial behind it and puts the most acid on your teeth.¹

Is apple cider vinegar or berberine better for weight loss?

The pooled numbers are of a size: vinegar about 1 kg across 12 trials, berberine 0.88 kg across 23 trials and 2.07 kg in the most favourable pooling of 12, all in adults mostly with metabolic conditions.^{2, 10, 11} Neither has an authorised weight claim in Great Britain, and no trial has compared them. Does berberine work for weight loss has berberine's record and the berberine guide the rest.

Can I take apple cider vinegar alongside a GLP-1 medicine?

No trial has tested the two together; the benefits page sets out why anyone on a GLP-1 medicine should ask their prescriber or pharmacist before taking vinegar daily.

What do apple cider vinegar before-and-after results show?

The before-and-after that exists is the trial record: about 1 kg over 4 to 12 weeks in the pooled trials and 1.2 to 1.9 kg in the 12-week Japanese trial, returning to baseline within four weeks of stopping.^{1, 2} A photo or testimonial quoting more than that is quoting a change the trials never recorded; the one trial that did has been withdrawn.⁴

Sources

1. 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. Double-blind randomised placebo-controlled trial, 175 obese Japanese adults randomised (59, 58 and 58), 155 completed, 15 or 30 mL of apple vinegar a day (750 or 1,500 mg acetic acid) in a 500 mL drink, 12 weeks with a 4-week follow-up; visceral fat by CT; all authors employed by a vinegar manufacturer. PubMed 19661687.
2. 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, vinegars of all types, 1.5 to 60 mL a day, 5 days to 12 weeks, mean difference 1.06 kg (95% CI 0.52 to 1.60), certainty graded high; funded by a university students' research centre in Tehran; no conflicts declared. PubMed 42110393.
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, 5 to 30 mL a day or an effervescent tablet, 4 to 12 weeks; 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. Retraction: Apple cider vinegar for weight management in Lebanese adolescents and young adults with overweight and obesity. BMJ Nutrition, Prevention & Health, 2025. Retraction notice of 23 September 2025 for the 2024 four-arm trial (120 recruited, 5, 10 or 15 mL a day, 12 weeks), whose record carries "Retracted Publication" and declares no competing interests. PubMed 41789013.
5. Great Britain nutrition and health claims (NHC) register: apple cider vinegar, entry 1380, "Helps control and normalize body weight", non-authorised; entries 1377, 1378 and 1379 also non-authorised. gov.uk. Register version 19 May 2026. Read 2 November 2026.
6. Najafi A, et al. Adjunctive effects of apple cider vinegar on metabolic syndrome and insulin resistance in polycystic ovary syndrome patients receiving metformin. Scientific Reports, 2026. Double-blind randomised placebo-controlled trial, 94 women with PCOS and metabolic syndrome on metformin, three 500 mg vinegar-powder capsules a day (1,500 mg, stated as 1,050 mg acetic acid), 12 weeks; no competing interests declared; no funding statement in the paper. PubMed 42215584.
7. Darzi J, et al. Influence of the tolerability of vinegar as an oral source of short-chain fatty acids on appetite control and food intake. International Journal of Obesity, 2014. Two randomised crossover meal studies, 16 and 14 healthy young adults, University of Surrey; research support from a source other than the US government listed on PubMed, funder not named. PubMed 23979220.
8. Cobb KM, et al. Acetic acid supplementation: effect on resting and exercise energy expenditure and substrate utilization. International Journal of Exercise Science, 2021. Randomised double-blind crossover trial, 16 healthy adults, 30 mL of apple cider vinegar a day in 1 L of drink, 4 days; funding not stated on PubMed. PubMed 34055150.
9. Hlebowicz J, et al. Effect of apple cider vinegar on delayed gastric emptying in patients with type 1 diabetes mellitus. BMC Gastroenterology, 2007. Investigator-blinded crossover pilot, 10 adults with type 1 diabetes and gastroparesis, 30 mL in 200 mL water; funded by grants from the Malmö Diabetes Association (full text). PubMed 18093343.
10. Elahi Vahed I, et al. The effect of berberine on obesity indices. International Journal of Obesity, 2026. Meta-analysis, 23 randomised trials in adults, body weight 0.88 kg lower than control; no competing interests declared. PubMed 41310257.
11. Asbaghi O, et al. The effect of berberine supplementation on obesity parameters. Clinical Nutrition ESPEN, 2020. Meta-analysis, 12 randomised trials, body weight 2.07 kg lower than control; no conflicts declared. PubMed 32690176.
12. Jafarirad S, et al. The improvement effect of apple cider vinegar as a functional food on anthropometric indices, blood glucose and lipid profile in diabetic patients: a randomized controlled clinical trial. Frontiers in Clinical Diabetes and Healthcare, 2023. Randomised controlled open-label trial, 80 adults with type 2 diabetes, 30 mL of apple cider vinegar a day in 100 mL of water for 8 weeks with the same diet advice in both groups; the authors declare no commercial or financial relationships. PubMed 38028980.

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This article is general information, not medical advice. Unexplained weight change needs a GP; if you take glucose-lowering medicines or a GLP-1 medicine, 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.