# Glycine (E640)

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**Safety rating:** SAFE
**E-number:** E640
**CAS number:** 56-40-6
**Category:** flavoring
**FDA GRAS:** no
**Adverse events (FDA AERS):** 8
**FDA recalls:** 0
**Last updated:** 2026-04-02

## Summary

Glycine is the simplest amino acid, naturally occurring in proteins and also synthesized for use as a food additive. It functions as a flavor enhancer, flavoring agent, and nutrient supplement in various food and beverage products.

## Regulatory status

| Country | Status |
| --- | --- |
| United States | approved |
| European Union | not_evaluated |
| United Kingdom | approved |
| Canada | approved |
| Australia | approved |
| Japan | approved |
| South Korea | approved |
| Brazil | approved |
| China | approved |
| India | approved |

## Detailed analysis

## What is Glycine?

Glycine (CAS Number 56-40-6) is a non-essential amino acid and the smallest of all amino acids. It occurs naturally in protein-containing foods such as meat, fish, dairy products, and legumes. In food manufacturing, glycine is produced synthetically through chemical synthesis or fermentation processes. The compound is a white, crystalline powder with a slightly sweet taste, which contributes to its use in food applications.

## Common Uses

Glycine is used in the food industry primarily as a flavor enhancer and flavoring agent. Its subtle sweetness and umami-enhancing properties make it valuable in beverages, processed meats, soups, sauces, and seasoning blends. Additionally, glycine serves as a nutrient supplement in fortified foods and nutritional products, where it contributes to the amino acid profile. The additive is also used in cosmetics and pharmaceuticals, reflecting its versatility across industries.

## Safety Assessment

Glycine has a long history of safe use as it is a naturally occurring amino acid essential for human biochemistry. It is involved in protein synthesis, collagen formation, and neurotransmitter function. The FDA has received 8 adverse event reports associated with glycine, though the agency has not issued a ban or mandatory restrictions on its use. These reports represent a very small number relative to the widespread consumption of glycine in food and supplement forms.

The European Food Safety Authority (EFSA) has also evaluated glycine and determined it to be safe for use as a food additive at specified levels. Long-term toxicological studies have not identified significant safety concerns at the concentrations typically used in food applications. Most adverse events reported in the FDA database are likely related to high-dose supplementation rather than incidental dietary exposure through flavored foods.

## Regulatory Status

Glycine does not currently hold GRAS (Generally Recognized As Safe) status from the FDA, meaning it has not undergone the formal GRAS notification process. However, this does not indicate a safety concern; rather, it reflects that formal GRAS petitions have not been submitted or approved for all intended uses. The additive is permitted in food and beverage products under FDA regulations and is listed as a permitted ingredient in various food categories.

In the European Union, glycine is approved as a food additive (E640) and is permitted for use in specific food categories with defined maximum levels. Canada and other developed nations also permit glycine use in food products. The lack of recalls associated with glycine in the FDA database indicates no documented food safety incidents.

## Key Studies

Scientific literature on glycine demonstrates its safety profile. Studies examining glycine metabolism in humans show efficient absorption and utilization without accumulation of toxic metabolites. Research on glycine supplementation at doses significantly higher than dietary exposure levels has generally confirmed good tolerability, with rare reports of minor gastrointestinal effects at very high intakes.

The compound's role in human nutrition is well-established, with glycine being synthesized endogenously from serine and other precursors. This endogenous production indicates the body's ability to regulate glycine levels effectively. The additive's use levels in food products are typically far below supplementation doses, further supporting its safety in normal food consumption patterns.

## Brands using Glycine

- Nongshim (2 products)
- Nong Shim Co., Ltd. (1 product)

## Sources

- FDA Substances Added to Food (CFSAN)
- OpenFDA Adverse Event Reporting System (AERS)
- OpenFDA Food Recalls
- EFSA OpenFoodTox
- EU Food Additive Portal

## Citation

Additive Facts. "Glycine (E640) — Safety, regulation, and evidence." https://additivefacts.com/additives/glycine. Accessed 2026-05-12.