Apple cider vinegar side effects

At typical amounts, the side effect reported most often is mild gastrointestinal upset. A 2020 systematic review of 13 human and 12 animal studies found the risk of side effects at recommended intakes appears low. A capsule form carries one documented risk a liquid doesn't — lodging in the esophagus without enough water — and a small number of rarer, more serious cases have been published from long-term or heavy vinegar use.

The common one: mild GI upset

Across the vinegar safety literature, the effect that comes up most is stomach discomfort — burning, nausea or a feeling of fullness — usually tied to taking a larger amount, or an undiluted liquid amount, than the body is used to. A 2020 systematic review searched four databases and identified 13 human and 12 animal studies on apple vinegar's safety and metabolic effects; its overall read was that the risk of side effects at recommended amounts appears low, while flagging that the evidence base as a whole — for safety and for any benefit — isn't yet strong enough for firm conclusions.

The one specific to capsules: esophageal injury

A capsule that doesn't move through the esophagus quickly, with enough liquid, can lodge against the lining. That's not a theoretical risk: a 2005 case tied to an apple cider vinegar tablet prompted researchers to test eight commercial tablet products for pH, acid content and microbial growth. They found considerable variability between brands — inconsistent pH, inconsistent acid content, and doubt about whether some products contained apple cider vinegar at all. It's the documented reason our own label directs 6-8 oz of water with every two-capsule serving, not a rounding suggestion.

The one specific to liquid: dental erosion

Undiluted liquid vinegar in direct, repeated contact with teeth is a different exposure than a capsule swallowed with water. An in-vitro study incubated human tooth enamel samples with five vinegar varieties (pH 2.7-3.95) for up to eight hours and measured mineral loss that varied by contact time and vinegar type. A capsule taken as directed doesn't put vinegar in contact with teeth the way sipping or "shooting" the liquid does — one of the few places where the capsule format has a documented advantage over the liquid, not just a taste preference.

Rarer, more serious reports

A handful of published case reports describe more serious effects tied to heavy or long-term vinegar intake, not typical supplement use:

• Liver injury. A case report described a 60-year-old man with a long history of vinegar consumption who developed liver injury; his liver values improved once he stopped. The authors call this an uncommon but real reported effect.
• Acute pancreatitis. A case report described an 84-year-old woman who developed acute pancreatitis shortly after starting an apple cider vinegar supplement — the authors describe the link as possible, not proven, and note how little data exists on this specific risk.
• Low blood potassium, elevated renin and bone loss. A published case report described a patient who developed all three after drinking large amounts of cider vinegar over time — a pattern tied to sustained, heavy intake, not label-directed supplement use.

These are single-patient reports, not trials, and each involved consumption well beyond a typical two-capsule serving. They're worth knowing, not a reason to expect the same outcome from label-directed use — and a reason to talk to a doctor if you're consuming vinegar in any form well beyond what a label directs, especially over a long period.

What we won't claim

We don't claim this capsule is gentler, safer or better tolerated than other apple cider vinegar forms or brands. No head-to-head trial establishes that, and the documented risks above — esophageal injury for capsules, dental erosion for liquids — are properties of the format generally, not something our specific label has been tested against.

Our label, for reference

Electric Tiger Apple Cider Vinegar Capsules: 1,000 mg organic apple cider vinegar powder, 200 mg inulin, 100 mg digestive enzyme blend, and Lactobacillus acidophilus LA85, per two-capsule serving. Directions: two capsules daily with 6-8 oz of water — the water is the one instruction the research above gives a documented reason for.

Questions people ask

What are the side effects of apple cider vinegar?

Most commonly, mild gastrointestinal upset at higher or undiluted amounts. Capsule-specific risk centers on the esophagus if taken without enough water; liquid-specific risk centers on tooth enamel with direct, repeated contact. Rarer published cases describe liver injury, pancreatitis, and — with sustained heavy intake — low blood potassium and bone loss.

Can apple cider vinegar capsules hurt your throat?

Yes, if taken without enough liquid. A published case and subsequent product testing documented esophageal injury linked to an apple cider vinegar tablet. Taking capsules with the full 6-8 oz of water our label directs is the documented way to avoid this.

Does apple cider vinegar damage your teeth?

Undiluted liquid vinegar, in direct and repeated contact with teeth, has been shown in lab testing to erode enamel. A capsule swallowed with water doesn't create that same direct, repeated contact.

Is apple cider vinegar bad for your kidneys?

We haven't found a trial establishing that typical supplement use affects the kidneys in people with normal kidney function. One published case describes electrolyte and bone changes after years of heavy vinegar intake, well beyond label-directed use — if you have kidney disease or any related condition, ask your doctor before adding any vinegar product.

How long do apple cider vinegar side effects last?

Mild GI upset generally resolves when the dose is lowered or stopped, based on the pattern across the studies reviewed above. The rarer, more serious cases described above involved sustained heavy use and improved after that use stopped — not something a single serving would be expected to cause.