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Apple Cider Vinegar: What the Trials Show for Weight, Blood Sugar and Reflux, and the Side Effects

Apple cider vinegar has small, uncertain effects. Pooled vinegar trials found fasting blood sugar lower in type 2 diabetes and weight about 1 kg lower (both grade C), but they mix vinegar types, and a widely shared weight-loss trial was retracted. No published trial has tested it for acid reflux. Diluted vinegar drinks twice a day raised tooth-wear scores within 8 weeks, a tablet injured one user's esophagus, and years of heavy use caused low potassium in one case.

Published How we grade evidenceEditorial policy

Apple cider vinegar is vinegar made from fermented apples, sold as a liquid, tablets, capsules and gummies; a 2025 review says the vinegar in its diabetes trials was about 5% acetic acid (Arjmandfard 2025). This guide covers adults drinking or swallowing it, and the harms to teeth, throat and potassium that are easy to miss.

The short version

  • Weight: about 1 kg more weight loss than in control groups, but no change in BMI, in 12 pooled trials that mix apple cider vinegar with other vinegars and a barberry product; two placebo-controlled apple cider vinegar trials disagree. Grade C (Shahmohammadi 2026; Kondo 2009; Castagna 2025). A widely shared 2024 weight-loss trial was retracted; none of these results depends on it (Abou-Khalil 2024, retracted).
  • Fasting blood sugar in type 2 diabetes: about 22 mg/dL lower in 7 small, mostly low-quality trials (about 16 mg/dL in the 3 blinded ones); one used white vinegar and one a barberry study, and a 2026 review of all vinegars found about 9 mg/dL. Grade C (Arjmandfard 2025; Shahmohammadi 2026).
  • Cholesterol and blood pressure: in mixed vinegar trials, systolic pressure about 3 mmHg lower (high certainty) and total cholesterol about 9 mg/dL lower (very low certainty); LDL, HDL, triglycerides and diastolic pressure unchanged. Grade C (Shahmohammadi 2026; Kondo 2009; Gheflati 2019).
  • Acid reflux and heartburn: no published trial (PubMed search, 9 November 2026; Ahuja 2019).
  • Harms: tooth-wear scores rose 18% in 8 weeks on diluted vinegar drinks (2 tablespoons in a cup of water, twice a day) and not on a low-acid pill; case reports describe a tablet throat injury, esophageal ulcers from a strong vinegar drink, and low potassium after years of heavy use. Grade C for tooth wear; grade D for the rest (case reports) (Anderson 2021; Hill 2005; Chang 2020; Lhotta 1998).
Question (who, compared with what)What trials foundSize of effectGrade
Weight (overweight, obesity or type 2 diabetes; mixed vinegars)Weight lower, BMI unchangedAbout 1 kgC
Fasting blood sugar (type 2 diabetes; 5 of 7 trials apple cider vinegar)LowerAbout 22 mg/dL (16 in blinded trials)C
Cholesterol, blood pressure (mixed vinegars)Systolic pressure, total cholesterol lowerAbout 3 mmHg; 9 mg/dLC
Acid refluxNot testedNo trialsNone
Tooth wear (diluted drink twice a day vs low-acid pill)Rose on the drink, not the pill18% in 8 weeksC (harm)

Does apple cider vinegar help you lose weight?

Grade C: about 1 kg, from small trials that mix vinegars and other treatments. A 2026 umbrella review re-pooled 12 trials in 918 adults with overweight, obesity or type 2 diabetes: weight was about 1 kg lower with vinegar than in control groups (high certainty, clearer in the apple cider vinegar trials), but BMI did not change (Shahmohammadi 2026). The pool is not apple cider vinegar alone: it includes red wine vinegar, pomegranate vinegar and a barberry study, and in some trials both groups also took metformin or dieted.

Two placebo-controlled trials of apple cider vinegar alone point both ways. The larger, double-blind and run by researchers at a vinegar company, gave 175 adults in Japan with a BMI of 25 to 30 (obese by Japanese criteria) a 500 mL drink with 15 or 30 mL of apple vinegar, or a placebo drink, daily for 12 weeks. Weight fell about 1 to 2 kg from the start on vinegar while the placebo group gained a little, so the vinegar groups lost about 1.6 to 2.3 kg more; weight, waist, belly fat and triglycerides were significantly lower than on placebo (Kondo 2009). But in a 12-week trial in 110 adults with type 2 diabetes, 15 mL a day did not change weight or other body measures against a vinegar-flavored placebo, as summarized in a 2025 review (Castagna 2025). Small trials, mixed vinegars and a split between the two cleanest trials keep the grade at C, as in our weight-loss guide.

The retracted trial. A 2024 trial in 120 young people in Lebanon reported weight loss and was retracted in 2025 (Abou-Khalil 2024, retracted). The 2025 review rated it low risk of bias and kept it even in its lower-risk analysis, so this guide does not use that review's pooled weight result (Castagna 2025); the 2026 review's weight pool does not include it.

Appetite. In a study of 16 young adults, vinegar with breakfast did cut appetite, but mainly because it made people feel sick; the authors said promoting vinegar as an appetite suppressant does not seem appropriate (Darzi 2014). See obesity and overweight.

Does apple cider vinegar help blood sugar in type 2 diabetes?

Grade C: a modest drop in fasting sugar, from mostly low-quality trials. A 2025 review pooled 7 trials in 463 adults with type 2 diabetes (13.75 to 30 mL of vinegar a day for 4 to 12 weeks, against placebo, water, diet advice alone or nothing): fasting blood sugar fell about 22 mg/dL more than in the comparison groups (moderate certainty), and about 16 mg/dL in the 3 blinded trials. The review counts all 7 as apple cider vinegar, but one used white vinegar (one of the 3 blinded trials) and one comes from a study of a processed barberry product; 5 of the 7 were low quality. HbA1c, a 3-month sugar average, fell by about 1.5 points in the 4 trials that measured it, but the results varied widely and depended on 2 of the trials (low certainty) (Arjmandfard 2025). The 2026 umbrella review, pooling many kinds of vinegar in people with and without diabetes, found smaller drops: about 9 mg/dL in fasting sugar (19 trials) and about 0.7 points in HbA1c (11 trials), with very inconsistent results between trials (Shahmohammadi 2026).

With meals: in 16 adults with type 2 diabetes, vinegar lowered the sugar rise after a high-glycemic meal (mashed potatoes) but not a low-glycemic one (Liatis 2010), and in another study it did not improve a glucose tolerance test (van Dijk 2012). The grade matches our blood sugar guide. Don't stop, skip or swap a diabetes medicine for vinegar; see type 2 diabetes and prediabetes.

Does apple cider vinegar lower cholesterol or blood pressure?

Grade C: small effects, from mixed vinegar trials. The 2026 umbrella review found systolic blood pressure about 3 mmHg lower (high certainty, from 7 trials that include a barberry study and a ginseng vinegar extract), with no change in diastolic pressure. Total cholesterol was about 9 mg/dL lower (very low certainty, 15 trials of several vinegars), and LDL, HDL and triglycerides did not change (Shahmohammadi 2026). In the Japanese weight trial, triglycerides ended lower than on placebo in both vinegar groups, total cholesterol only on the low dose and systolic pressure only on the high dose (Kondo 2009); in 70 adults with type 2 diabetes, 20 mL a day for 8 weeks did not change blood pressure (Gheflati 2019). See high cholesterol, high blood pressure and the cholesterol guide.

Does apple cider vinegar help acid reflux or heartburn?

No published trial has tested apple cider vinegar for acid reflux (GERD) or heartburn. A PubMed search on 9 November 2026 lists 5 papers, none of them a vinegar trial. A 2019 review of popular remedies for reflux and other esophageal symptoms, apple cider vinegar among them, found a wide gap between stories and evidence for most of them (Ahuja 2019). Reflux and burping appear in a 2025 review's list of side effects of vinegar in large amounts (Ijaz 2025). For treatments that have been tested, see heartburn and reflux and the reflux protocol.

Does apple cider vinegar help gut health, bloating or digestion?

Grade D: animal studies only. In mice on a high-fat diet, apple cider vinegar powder changed gut bacteria and reduced liver damage (Ding 2025). In people with type 1 diabetes and slow stomach emptying, apple cider vinegar slowed emptying further (Hlebowicz 2007), which is not the same as better digestion, and gas, burping and constipation are among its reported side effects (Ijaz 2025). See indigestion.

Liquid, capsules or gummies: does the form matter?

The trials used liquid vinegar, about 14 to 30 mL (1 to 2 tablespoons) a day, diluted in water or a drink (one gave it in a 500 mL drink), and one used effervescent tablets (Arjmandfard 2025; Kondo 2009; Castagna 2025). Even diluted, a vinegar drink twice a day raised tooth-wear scores within 8 weeks (Anderson 2021). When researchers tested eight vinegar tablet products after a throat injury, tablet size, acidity, acid content and label claims varied widely, and it was unclear whether the products contained apple cider vinegar at all (Hill 2005). None of the trials above tested gummies. Vinegar concentrates are stronger: acetic acid above 20% can cause caustic injury to the esophagus (Ijaz 2025).

What we'd skip

  • Undiluted shots or strong vinegar drinks: a 15-year-old who drank a commercial vinegar drink daily without enough dilution vomited blood from ulcers along the whole esophagus (Chang 2020).
  • Vinegar tablets: one injured a user's esophagus, and tested products were unreliable (Hill 2005).
  • Vinegar on skin tags, moles or warts: apple cider vinegar applied to the skin has caused a chemical burn (Bunick 2012); see the warts guide.

Safety and interactions

  • Teeth: in 8 weeks, tooth-wear scores rose 18% in healthy adults drinking 2 tablespoons of vinegar in a cup of water twice a day, and did not change on a low-acid vinegar pill (Anderson 2021). A 15-year-old girl who drank apple cider vinegar daily to lose weight developed erosion of her teeth (Gambon 2012).
  • Throat and esophagus: tablets and strong drinks have caused injuries (see What we'd skip). Swallow nothing undiluted.
  • Low potassium and bones: a case report describes low potassium (hypokalemia), high renin and thinning bones (osteoporosis) in a woman who drank large amounts of cider vinegar (Lhotta 1998); a 2025 review gives the amount as 250 mL a day for 6 years (Ijaz 2025).
  • Diuretics and digoxin: water pills such as furosemide can lower potassium, and the furosemide label says digitalis drugs can exaggerate the effects of low potassium (furosemide label); the digoxin label lists low potassium among things that "may predispose to digoxin toxicity" (digoxin label). No studies have tested apple cider vinegar with diuretics or digoxin; ask your prescriber before using vinegar regularly.
  • Insulin and diabetes medicines: in 10 people with type 1 diabetes and gastroparesis (slow stomach emptying), 30 mL a day slowed emptying further (Hlebowicz 2007), and people with type 1 diabetes taking it had more low blood sugar episodes, according to a 2025 review (Ijaz 2025). With insulin or other diabetes medicines, vinegar may add to their effect: check your sugar more often, and with gastroparesis ask your diabetes team first.
  • Other medicines: no studies have tested apple cider vinegar with levothyroxine, warfarin or apixaban (Eliquis), or with blood pressure medicines. Ask your pharmacist.
  • Liver: a 2025 case report describes liver injury in a 60-year-old man with a long history of vinegar use, which improved after he stopped (Andonie 2025).
  • How much: there is no set upper limit for vinegar. Trials used about 14 to 30 mL (1 to 2 tablespoons) a day, diluted, for up to 12 weeks (Arjmandfard 2025; Kondo 2009); even diluted, twice-daily drinks raised tooth-wear scores within 8 weeks (Anderson 2021), and 250 mL a day for years caused low potassium in one case (Lhotta 1998; Ijaz 2025). A 2020 systematic review judged the risk of side effects small at recommended amounts taken in recommended ways (Launholt 2020).
  • Pregnancy: there are no studies of apple cider vinegar as a supplement in pregnancy; use it only as your midwife or obstetric team advises.
  • Breastfeeding? Ask your midwife, doctor or a lactation specialist, who can check what passes into breast milk.
  • Children: ask your child's doctor; the tooth and throat injuries above both happened in 15-year-olds.

When to see a doctor

  • Emergency (911) for vomiting blood, black stools, severe chest or upper-belly pain, or trouble swallowing after vinegar or a vinegar tablet.
  • Same day for muscle weakness, cramps, a racing or irregular heartbeat, or confusion, which can signal low potassium or other salt imbalances, especially on a water pill or digoxin (HCTZ label); or for signs of low blood sugar, such as trembling, sweating or confusion, if you use diabetes medicine.
  • Soon for yellowing of the skin or eyes, or dark urine; heartburn more than twice a week, or heartburn with weight loss or trouble swallowing; or sensitive or worn teeth (see a dentist).

Don't stop a prescribed medicine on your own; ask the prescriber or pharmacist. Pregnant? Let your midwife or obstetric team decide. Under 18? Check with a clinician first.

FAQ

Does apple cider vinegar help you lose weight? A little at most (grade C): pooled trials of several vinegars found about 1 kg more weight loss than in control groups, with no change in BMI. One placebo-controlled trial found 1.6 to 2.3 kg more loss in 12 weeks, another found none, and a widely shared 2024 trial was retracted.

Does apple cider vinegar lower blood sugar? Somewhat (grade C): in 7 small, mostly low-quality trials in type 2 diabetes, 5 of them of apple cider vinegar, fasting sugar fell about 22 mg/dL; a review of all vinegars found about 9 mg/dL. It does not replace diabetes medicine and may add to its lowering.

Is apple cider vinegar good for acid reflux? No published trial has tested it, and reflux and burping are listed side effects of vinegar in large amounts. See a doctor if heartburn happens more than twice a week.

Are apple cider vinegar gummies or pills as good as the liquid? The trials used diluted liquid, and one used effervescent tablets; none tested gummies. Tested vinegar tablets varied widely in acid content, and one injured a user's esophagus.

Is it safe to drink apple cider vinegar every day? Trials gave about 14 to 30 mL (1 to 2 tablespoons) a day, diluted, for up to 12 weeks. Even diluted, twice-daily vinegar drinks raised tooth-wear scores within 8 weeks, and years of heavy use caused low potassium in one case; ask first if you take a water pill, digoxin or insulin.

Sources

  1. Arjmandfard D, et al. Effects of apple cider vinegar on glycemic control and insulin sensitivity in patients with type 2 diabetes: A GRADE-assessed systematic review and dose-response meta-analysis of controlled clinical trials. Front Nutr. 2025. PubMed 39949546 · doi:10.3389/fnut.2025.1528383
  2. Shahmohammadi F, et al. Vinegar Consumption and Health: An Umbrella Review of Meta-Analyses of Randomized Controlled Trials. Food Sci Nutr. 2026. PubMed 42110393 · doi:10.1002/fsn3.71849
  3. Kondo T, et al. Vinegar intake reduces body weight, body fat mass, and serum triglyceride levels in obese Japanese subjects. Biosci Biotechnol Biochem. 2009. PubMed 19661687 · doi:10.1271/bbb.90231
  4. Castagna A, et al. Effect of Apple Cider Vinegar Intake on Body Composition in Humans with Type 2 Diabetes and/or Overweight: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients. 2025. PubMed 41010525 · doi:10.3390/nu17183000
  5. Abou-Khalil R, et al. Apple cider vinegar for weight management in Lebanese adolescents and young adults with overweight and obesity: a randomised, double-blind, placebo-controlled study. BMJ Nutr Prev Health. 2024. PubMed 38966098 · doi:10.1136/bmjnph-2023-000823
  6. Gheflati A, et al. The effect of apple vinegar consumption on glycemic indices, blood pressure, oxidative stress, and homocysteine in patients with type 2 diabetes and dyslipidemia: A randomized controlled clinical trial. Clin Nutr ESPEN. 2019. PubMed 31451249 · doi:10.1016/j.clnesp.2019.06.006
  7. Ahuja A, et al. Popular Remedies for Esophageal Symptoms: a Critical Appraisal. Curr Gastroenterol Rep. 2019. PubMed 31289950 · doi:10.1007/s11894-019-0707-4
  8. Anderson S, et al. Evidence That Daily Vinegar Ingestion May Contribute to Erosive Tooth Wear in Adults. J Med Food. 2021. PubMed 33297831 · doi:10.1089/jmf.2020.0108
  9. Hill LL, et al. Esophageal injury by apple cider vinegar tablets and subsequent evaluation of products. J Am Diet Assoc. 2005. PubMed 15983536 · doi:10.1016/j.jada.2005.04.003
  10. Chang J, et al. Corrosive Esophageal Injury due to a Commercial Vinegar Beverage in an Adolescent. Clin Endosc. 2020. PubMed 31405264 · doi:10.5946/ce.2019.066
  11. Lhotta K, et al. Hypokalemia, hyperreninemia and osteoporosis in a patient ingesting large amounts of cider vinegar. Nephron. 1998. PubMed 9736833 · doi:10.1159/000045180
  12. 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. Int J Obes (Lond). 2014. PubMed 23979220 · doi:10.1038/ijo.2013.157
  13. Liatis S, et al. Vinegar reduces postprandial hyperglycaemia in patients with type II diabetes when added to a high, but not to a low, glycaemic index meal. Eur J Clin Nutr. 2010. PubMed 20502468 · doi:10.1038/ejcn.2010.89
  14. van Dijk JW, et al. Vinegar co-ingestion does not improve oral glucose tolerance in patients with type 2 diabetes. J Diabetes Complications. 2012. PubMed 22699111 · doi:10.1016/j.jdiacomp.2012.05.009
  15. Ijaz R, et al. Role of vinegar in cardiovascular health: A narrative review. J Biol Methods. 2025. PubMed 41415882 · doi:10.14440/jbm0033
  16. Ding Q, et al. Apple Cider Vinegar Powder Mitigates Liver Injury in High-Fat-Diet Mice via Gut Microbiota and Metabolome Remodeling. Nutrients. 2025. PubMed 40647261 · doi:10.3390/nu17132157
  17. Hlebowicz J, et al. Effect of apple cider vinegar on delayed gastric emptying in patients with type 1 diabetes mellitus: a pilot study. BMC Gastroenterol. 2007. PubMed 18093343 · doi:10.1186/1471-230X-7-46
  18. Bunick CG, et al. Chemical burn from topical apple cider vinegar. J Am Acad Dermatol. 2012. PubMed 22980269 · doi:10.1016/j.jaad.2011.11.934
  19. Gambon DL, et al. [Unhealthy weight loss. Erosion by apple cider vinegar]. Ned Tijdschr Tandheelkd. 2012. PubMed 23373303 · doi:10.5177/ntvt.2012.12.12192
  20. Andonie CR, et al. Apple Cider Vinegar-Induced Hepatotoxicity: A Rare Case Report. Oxf Med Case Reports. 2025. PubMed 40666072 · doi:10.1093/omcr/omaf097
  21. Launholt TL, et al. Safety and side effects of apple vinegar intake and its effect on metabolic parameters and body weight: a systematic review. Eur J Nutr. 2020. PubMed 32170375 · doi:10.1007/s00394-020-02214-3