Apple cider vinegar (ACV) has become one of the most talked-about superfoods in wellness, with researchers and influencers alike praising its supposed benefits. Some small studies suggest it may support weight loss and help with blood sugar management, but that doesn’t mean it’s a good idea to sip it daily without caution. If you’re regularly drinking or using ACV, the potential side effects are worth knowing.
Here’s what the experts and research reveal about the possible downsides of ACV and why it might not always be the wellness shortcut it’s made out to be.
What is apple cider vinegar?
Apple cider vinegar is made from fermented apples, explains quadruple board-certified physician and internal medicine specialist Dr Raj Dasgupta. “It’s typically used in cooking and as a home remedy,” he says. The active compound is acetic acid, which gives ACV its tangy taste and is linked to proposed benefits such as better blood sugar control, cholesterol support, fat metabolism, and even weight loss.
But there’s a catch: much of the evidence is based on animal studies. While promising, more high-quality human research is needed to confirm whether ACV truly delivers on these claims.
Apple cider vinegar side effects
Apple cider vinegar might be a wellness favourite, but its benefits are not fully proven—and the side effects deserve attention too. Here’s what research says so far.
Tooth decay
Regular use of ACV can wear down tooth enamel over time, leaving teeth sensitive and prone to cavities, says Dr Dasgupta. A 2021 study in the Journal of Medicinal Food found that people who drank vinegar twice a day for eight weeks experienced 18% more tooth erosion than those who didn’t. Sipping it through a straw and rinsing with water afterwards may help reduce the risk.
Throat burns
Because ACV is highly acidic, drinking it undiluted can irritate the oesophagus. Over time, this may cause throat burns or ulcers, says Dr Dasgupta. In one case, a 15-year-old who consumed undiluted vinegar regularly developed throat ulcers and even vomited blood, according to Clinical Endoscopy. Always dilute it before drinking.
Low potassium and bone loss
Too much ACV can also affect mineral balance. “Consuming it may lower potassium levels, which can trigger muscle cramps,” says Dr Dasgupta. When taken in high amounts over time, it may also weaken bones. A review in Hormone and Metabolic Research explains that potassium is essential for bone health—helping with calcium absorption, activating vitamin D, and regulating the cells that build and break down bone tissue. A drop in potassium may undermine those processes.
Skin burns
ACV’s high acidity makes it risky to use straight on the skin. Anecdotal reports and case studies have linked undiluted ACV to chemical burns. Despite its popularity as a DIY skin or hair rinse, experts caution against applying it without serious dilution. Experts suggest mixing just half a tablespoon into a full glass of water to avoid irritation, burns, or long-term damage.
Gastrointestinal distress
The gut-health benefits of ACV are still debated. While some studies suggest it may support digestion, others show it can cause the opposite effect. Drinking too much ACV may lead to nausea or an upset stomach, says Dr Dasgupta. A study in the European Journal of Nutrition found that excess intake could delay stomach emptying (gastroparesis), leading to bloating and gas—a particular concern for people managing diabetes.
Medication interaction
ACV can also clash with certain medications, notes preventive cardiology dietitian Michelle Routhenstein.
- Diuretics (like furosemide or hydrochlorothiazide): Combining them with ACV may lower potassium levels, which can trigger muscle cramps, weakness, or even heart rhythm issues.
- Insulin: ACV may enhance insulin sensitivity and lower blood sugar, which could cause hypoglycaemia with symptoms like dizziness, confusion, headache, or fainting.
- Blood thinners (aspirin, warfarin, clopidogrel): Pairing them with ACV may heighten bleeding or bruising risk.
Because of these possible interactions, it’s crucial to speak with a healthcare provider before adding ACV to your daily routine, especially if you’re on long-term medication.
How to safely consume ACV
“To use ACV safely, drink one to two tablespoons a day mixed in at least one cup of water,” says Dr Dasgupta. Always use a straw to protect your teeth, then rinse your mouth with plain water to wash away any lingering acid. Avoid drinking it on an empty stomach, as that can increase the risk of discomfort or irritation.
Routhenstein adds that ACV doesn’t need to be sipped straight to deliver its potential perks. Stir it into salad dressings, whisk it into marinades, or use it as a zesty finishing splash over cooked veggies for a more enjoyable—and safer—way to include it in meals.
Who should avoid apple cider vinegar?
Not everyone is a good candidate for ACV. “People with digestive issues like gastroparesis or reflux should steer clear, as it can make symptoms worse,” says Dr Dasgupta. Those with low potassium levels, weakened enamel, or sensitive teeth should also be cautious.
Routhenstein adds that pregnant and breastfeeding women, as well as anyone with chronic health concerns or on regular medication, should check with their doctor before adding ACV to their diet. Safety should always come first.
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