Can too much citric acid be harmful?

November 1, 2025 •

3 min read

The U.S. Food and Drug Administration (FDA) classifies citric acid as "generally recognized as safe" (GRAS) for use in food, but this safety designation applies to moderate consumption. It is important to know that consuming too much citric acid can be harmful, leading to dental, digestive, and other health issues, especially for sensitive individuals.

Quick Summary

Excessive intake of citric acid can cause dental enamel erosion, stomach upset, and inflammation, particularly from manufactured versions produced with mold. Those with GERD or sensitive skin should be particularly mindful of their intake.

Key Points

Dental Damage: Excessive intake of citric acid directly erodes tooth enamel, leading to increased sensitivity and a higher risk of cavities.
Digestive Distress: High quantities can irritate the stomach lining, trigger acid reflux, and worsen symptoms for individuals with GERD.
Allergic Reactions: Some sensitive people may experience inflammatory symptoms like joint pain or fatigue when consuming manufactured citric acid, possibly due to mold residues.
Skin Irritation: While used in cosmetics, concentrated citric acid can cause irritation, redness, and swelling, particularly on sensitive or broken skin.
Source Matters: Natural citric acid from fruits poses fewer risks, whereas the manufactured version, derived from mold, has been linked to inflammatory responses in susceptible individuals.
Moderation is Key: Consuming citric acid in limited amounts and practicing good oral hygiene can mitigate the risk of adverse health effects.

Understanding Citric Acid: Natural vs. Manufactured

Citric acid is a weak organic acid found naturally in citrus fruits like lemons and limes, giving them their sour flavor. Beyond its natural form, a manufactured version is widely used as a food additive, preservative, and flavor enhancer. Approximately 99% of the world's production of manufactured citric acid is derived from the black mold Aspergillus niger, which ferments sugar to produce the acid. While the chemical compound itself is identical, some reports suggest that mold residues from the manufacturing process may trigger adverse inflammatory reactions in sensitive individuals, unlike the natural form.

Potential Harms of Excessive Citric Acid Intake

When consumed in moderation, citric acid is harmless for most people. However, frequent and excessive intake, especially from processed foods and beverages, can lead to several health problems.

Dental Erosion

This is one of the most well-documented risks associated with high acid consumption. Citric acid directly erodes tooth enamel, the protective outer layer of teeth.

Increased sensitivity: As enamel thins, teeth become more sensitive to hot, cold, and sweet foods.
Discoloration: Teeth may take on a dull or yellowish appearance as the underlying dentin becomes more visible.
Cavities: Once the protective enamel is compromised, the risk of developing cavities increases significantly.
Permanent damage: Enamel does not regenerate, so erosion is permanent.

Digestive System Issues

For individuals with pre-existing digestive conditions, high citric acid intake can exacerbate symptoms. It can also cause discomfort in those without existing issues when consumed excessively.

GERD and Acid Reflux: People with gastroesophageal reflux disease (GERD) or acid reflux should limit their intake, as citric acid can increase stomach acidity and relax the esophageal sphincter, triggering heartburn and reflux symptoms.
Stomach Irritation: High doses can irritate the stomach lining, leading to nausea, vomiting, or abdominal pain.
Gastrointestinal Distress: Some people may experience diarrhea or general gastrointestinal discomfort.

Skin and Eye Irritation

While citric acid is used in many cosmetics, applying it in high concentrations or to sensitive skin can cause irritation.

Topical application: Concentrated solutions can cause redness, itching, and swelling. Those with conditions like rosacea or dermatitis should be cautious.
Eye contact: Direct contact with the eyes can cause severe irritation, burning, and potential corneal damage.

Allergic and Inflammatory Reactions

While rare, there have been reports of allergic-like reactions to manufactured citric acid, possibly due to residual mold proteins. Symptoms include joint and muscle pain, fatigue, and even shortness of breath in hypersensitive individuals.

Mitigating the Risks of Excessive Citric Acid

To enjoy the benefits of citric acid while minimizing risks, consider these moderation strategies:

Reduce intake of acidic beverages: Limit consumption of sodas, sports drinks, and fruit juices that are high in citric acid.
Rinse with water: After consuming acidic foods or drinks, rinse your mouth with plain water to help neutralize the acid.
Use a straw: When drinking acidic beverages, a straw can help bypass your teeth, reducing direct exposure.
Delay brushing: Wait at least 30 minutes after consuming acidic foods before brushing your teeth to avoid damaging softened enamel.
Check food labels: Be mindful of citric acid listed as an additive, particularly if you have mold sensitivities.

Natural vs. Manufactured Citric Acid: A Comparison

To highlight the differences and potential concerns, here is a comparison of natural and manufactured sources of citric acid.


Feature	Natural Citric Acid (from fruit)	Manufactured Citric Acid (from mold)
Source	Citrus fruits (lemons, limes, oranges), berries, tomatoes.	Black mold (Aspergillus niger) grown on sugar.
Production	Part of the fruit's natural composition.	Industrial fermentation process.
Risks	Enamel erosion with excessive, frequent intake.	Enamel erosion; potential allergic reactions from mold residues in sensitive individuals.
Benefits	Found alongside beneficial vitamins (like Vitamin C) and minerals.	Acts as a preservative, flavor enhancer, and processing aid.
Regulation	Not regulated as an additive.	Classified as "Generally Recognized as Safe" (GRAS) by the FDA.

Conclusion: A Matter of Moderation

While citric acid is a safe and beneficial compound in moderation, the potential for harm increases with excessive intake, especially from processed sources. The risks range from dental enamel erosion and digestive irritation to potential allergic reactions linked to the manufactured version. By being mindful of your consumption, practicing good oral hygiene, and considering any personal sensitivities, you can safely enjoy the tart flavor and preservative qualities of citric acid without experiencing negative side effects.

For more detailed information on natural vs. manufactured sources and potential risks, read this guide on Healthline.com.

Frequently Asked Questions

For most people, moderate consumption of citric acid does not cause long-term health problems. However, excessive, long-term intake can lead to permanent dental enamel erosion and may exacerbate chronic digestive issues like GERD.

Natural citric acid is found in citrus fruits, while the manufactured version is produced by fermenting black mold (Aspergillus niger) with sugar. Although chemically identical, some report allergic reactions to the manufactured form, possibly due to residual mold fragments.

Citric acid is used in many skincare products as an AHA. It is generally safe in low concentrations, but high concentrations or application to sensitive/broken skin can cause irritation, redness, or burns.

To protect your teeth, limit acidic drink consumption, use a straw, rinse your mouth with water after exposure, and wait at least 30 minutes before brushing.

Yes, for people with acid reflux or GERD, citric acid can be bad. It increases stomach acidity and can cause the lower esophageal sphincter to relax, triggering or worsening reflux symptoms.

Individuals with diagnosed sensitivities to mold, GERD, or severe skin conditions should be cautious with or avoid excessive citric acid intake. If you experience adverse reactions, consult a doctor.

Citric acid is commonly consumed in foods and is considered generally safe during pregnancy. However, for use in medicinal amounts, it is best to consult a healthcare provider.