What Is Citric Acid?

If you ever sunk your teeth into a lemon, you've tasted citric acid. All citrus fruits have it. Manufacturers add a manmade version of it to processed foods. Medicines with citric acid in them treat health issues like kidney stones.

Where You Find It

It's not just sour citrus fruits that have citric acid. All plants and animals hold within them small traces of it.

You can also find citric acid in:

Packaged foods and drinks. Citric acid helps keep canned and jarred foods fresh over long periods of time. It can prevent some kinds of fresh-cut produce, like sliced apples, from turning brown.

Citric acid can also help thicken foods or give them a slightly sour flavor. That's why you might see citric acid listed as an ingredient in some ice creams, sorbets, or sodas.

Wine. Citric acid can balance out the acid in a food or drink. Winemakers sometimes add it to their products to improve the taste.

Medicines. Some creams include citric acid to help clear up skin infections. Other citric acid drugs that you take by mouth can reduce the amount of acid in your urine. This can help prevent kidney stones. You might also take citric acid for metabolic acidosis, a buildup of acid inside your body.

Personal care products. When manufacturers mix citric acid with other ingredients, they can form a compound called "alpha-hydroxy acid" that helps smooth your skin. It's also in some cosmetics and toiletries, like lipstick, hair spray, and deodorant, to help them last longer.

Household cleaners. Because citric acid can eat away at hard water buildup, you'll often see it in dishwasher detergent. Other household cleaners also include it as an ingredient since it can help remove stains and odors.

Disinfectants. Since citric acid kills some types of bacteria and viruses, you'll find it in insect sprays, products that kill fungus or algae, hand sanitizer, and even some tissues you use to blow your nose.

Environmental cleanup products. Citric acid can safely remove toxins from polluted soil and even clean up nuclear waste.



The FDA says citric acid is "generally recognized as safe" in food and skin products. Still, some experts think that more research is needed.

Citric acid may cause:

Skin irritation. When it touches your skin for long periods of time, it can cause stinging, swelling, or hives.

Eye pain. It will burn if it gets in your eyes. If this happens, flush them well with water for several minutes. If you wear contact lenses, take them out as soon as you can.

Tooth problems. Drinks and candies that contain citric acid can wear away the enamel (the outer layer) of your teeth. This can make your teeth more sensitive, turn them yellow, and make it more likely you'll get cavities.

Upset stomach. If you take a medicine with citric acid by mouth, you can have side effects like nausea or vomiting.

Sometimes, drugs with citric acid can cause severe side effects, such as:

If you notice any of these symptoms, contact your doctor right away.

WebMD Medical Reference Reviewed by Neha Pathak, MD on August 26, 2019



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ChemistrySafetyFacts.org/American Chemistry Council: "Citric Acid."
CosmeticsInfo.org: "Citric Acid."

Toxicology Reports: "Potential role of the common food additive manufactured citric acid in eliciting significant inflammatory reactions contributing to serious disease states: A series of four case reports."

American Academy of Allergy Asthma & Immunology: "Citric Acid and Citrus Allergy."

Cleveland Clinic: "Citric Acid; Potassium Citrate Oral Solution."

Eatright.org: "What are Food Additives?"

Chemistry Central Journal: "Citric acid: emerging applications of key biotechnology industrial product."

Cosmetic Ingredient Review: "Final Report: On the Safety Assessment of Citric Acid, Inorganic Citrate Salts, and Alkyl Citrate Esters as Used in Cosmetics."

American Dental Association: "Erosion: What You Eat and Drink Can Impact Teeth."

National Kidney Foundation: "Metabolic Acidosis."

European Union: "Citric Acid: Evaluation of Active Substances/Assessment Report."

Mayo Clinic: "Food Allergy vs. Food Intolerance: What's the Difference?"

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