How Does Erythrosine Affect the Body? Unpacking the Health Impacts

January 7, 2026 •

3 min read

According to a January 2025 announcement, the FDA has banned erythrosine (Red Dye No. 3) in food and ingested drugs in the United States due to mounting evidence of potential health risks. This synthetic food dye, also known as E127, has been the subject of debate for years concerning its potential impact on human health, raising questions about its effects on the body.

Quick Summary

Erythrosine, or Red Dye No. 3, is a synthetic food dye linked to potential health risks. Animal studies show associations with thyroid hormone disruption, neurotoxicity, and behavioral issues. Global regulatory stances vary, with some agencies enacting restrictions or bans in light of safety concerns.

Key Points

Thyroid Hormone Disruption: Erythrosine's iodine content and interference with thyroid hormone metabolism can lead to elevated TSH levels and potential thyroid dysfunction, a primary concern highlighted by regulators.
Neurotoxic Effects in Animals: Animal studies have linked high-dose erythrosine exposure to neurotoxicity, including oxidative stress, neuroinflammation, and impaired cognitive function.
Hyperactivity Link in Children: Research suggests a potential, though controversial, association between synthetic dyes like erythrosine and increased hyperactivity or ADHD-like symptoms in children.
Genotoxicity and Carcinogen Debate: Some studies indicate that erythrosine can cause DNA damage, but findings on its carcinogenic potential, particularly in humans, remain inconclusive and are a subject of regulatory debate.
Varied Global Regulations: Regulatory bodies differ significantly in their approach, with the US implementing a ban, the EU heavily restricting it, and other countries setting ADI limits.
High-Dose Animal Studies vs. Human Exposure: Much of the evidence for carcinogenicity and thyroid issues comes from high-dose animal studies, which may not directly translate to human risk at typical low-level dietary exposure.

What is Erythrosine (Red Dye 3)?

Erythrosine, known as FD&C Red No. 3 in the U.S. and E127 in Europe, is a bright red synthetic dye used in various food and pharmaceutical products. First approved in 1907, this xanthene dye has been used to color items such as maraschino cherries, candies, and processed foods. Its chemical structure contains iodine, which is relevant to some of its reported biological effects. Erythrosine's use has faced safety concerns and regulatory reviews over the years.

The Impact on Thyroid Health

A major concern regarding erythrosine is its potential effect on the thyroid gland. Due to its iodine content, the dye can interfere with thyroid hormone production and regulation. Studies in both humans and rats have shown that repeated consumption can increase levels of thyroid-stimulating hormone (TSH).

Erythrosine's Mechanism of Thyroid Disruption

Erythrosine is thought to disrupt thyroid hormone regulation through mechanisms including inhibiting the conversion of T4 to T3 and increasing serum iodine levels. In high-dose rat studies, this hormonal disruption stimulated TSH secretion, potentially leading to thyroid hyperstimulation.

Benign Thyroid Tumors in Animal Studies

Some long-term, high-dose rat studies linked chronic TSH stimulation to the development of benign thyroid tumors. However, experts believe these tumors are a secondary effect of hormonal imbalance rather than direct carcinogenicity. The relevance of these findings to human cancer risk is debated by regulatory bodies.

Neurotoxicity and Behavioral Effects

Animal studies also indicate potential neurotoxic effects from erythrosine exposure.

Oxidative Stress and Neuroinflammation

Research on rats suggests that erythrosine can impact brain function by increasing oxidative stress and neuroinflammation, altering neurotransmitter levels, and causing memory and neurobehavioral issues.

The Link to Hyperactivity in Children

The possible link between synthetic food dyes, including erythrosine, and hyperactivity in children remains controversial. While research is mixed, studies like the Southampton Six have raised concerns, leading to cautionary labeling and restrictions in some areas.

Genotoxicity and DNA Damage Concerns

Some in vitro and animal studies suggest erythrosine may be genotoxic and damage DNA. However, other studies have been inconclusive. A 2024 animal study noted DNA damage and oxidative stress in the gastrointestinal tract of rats given erythrosine.

The Regulatory Landscape for Erythrosine

Regulatory approaches to erythrosine vary globally due to differing interpretations of safety data.

A Comparison of Global Erythrosine Regulations


Aspect	United States (Pre-Jan 2025)	United States (Post-Jan 2025 Ban)	European Union	Canada	Australia/New Zealand
Status	Limited use in certain foods, oral drugs, and topical cosmetics.	Banned in all food and ingested drugs (effective 2027/2028).	Heavily restricted; permitted only in specific items like candied cherries and certain decorations.	Permitted in food colors.	Permitted below ADI.
Rationale	Previously considered safe at current exposure levels, but growing evidence led to ban.	Based on findings of carcinogenicity in animal studies and hyperactivity links.	Precautionary principle due to concerns, labeling requirements in some cases.	Deemed not to pose a health risk at regulated levels.	No basis to amend Acceptable Daily Intake (ADI).
Warning Labels	None on products containing the dye in food.	N/A (due to ban).	Required for products containing the dye regarding effects on children's activity and attention.	None, based on current assessment.	None required.

List of Potential Adverse Effects

Potential health effects linked to erythrosine include:

Thyroid Dysfunction: Disruption of thyroid hormone regulation and increased TSH levels.
Neurobehavioral Impairment: Effects on memory, learning, anxiety-like behaviors, and neuroinflammation observed in animal studies.
Increased Hyperactivity: Possible link to hyperactivity or ADHD symptoms in sensitive children.
DNA Damage: Indication of genotoxic effects in some studies.
Oxidative Stress: Increased oxidative stress markers in brain and gastrointestinal tissues in animals.
Gastrointestinal Toxicity: Degenerative changes and inflammation in the GI tract observed in studies.

Conclusion: Making Informed Choices

The effects of erythrosine on the body are debated, with significant concerns arising from animal studies, particularly regarding thyroid health and potential carcinogenicity. The varied regulatory responses globally highlight the ongoing scientific uncertainty. Consumers are encouraged to check ingredient labels for "Erythrosine" or "E127". Given the potential risks, especially with chronic exposure, and the availability of alternatives, minimizing intake of synthetic food dyes is a cautious approach. For further information on the FDA ban, consult the official announcement at PBS NewsHour.

Frequently Asked Questions

The U.S. Food and Drug Administration (FDA) banned erythrosine, effective in 2027/2028, primarily due to evidence from high-dose animal studies linking it to thyroid tumors in male rats. This action, following a 2022 petition, addressed long-standing concerns about the dye's potential carcinogenicity.

The main concern is its effect on the thyroid gland. Erythrosine contains iodine and can interfere with thyroid hormone metabolism, leading to elevated thyroid-stimulating hormone (TSH) levels and potentially contributing to thyroid dysfunction.

Yes, some animal studies have shown that high doses of erythrosine can have neurotoxic effects, including increasing oxidative stress and neuroinflammation in the brain, which may lead to impaired memory and neurobehavioral problems.

Some studies, like the "Southampton Six" study, have suggested a link between artificial food dyes, including erythrosine, and increased hyperactivity in children. While the exact mechanism is unclear and findings are mixed, this potential link has prompted regulatory caution and labeling requirements in some regions.

Regulations vary because different countries and agencies interpret the scientific data differently. Factors like the relevance of high-dose animal studies to human risk, conflicting genotoxicity results, and public pressure contribute to the diverse regulatory stances.

Historically, erythrosine has been used in products needing a vibrant cherry-red or pink color. This includes maraschino cherries, certain candies, cake decorating gels, and some processed fruits and snacks.

You can avoid erythrosine by carefully reading product ingredient labels and looking for Red Dye No. 3 or E127. Opting for products that use natural colorants or avoiding heavily processed and artificially colored foods can also help minimize exposure.