What is E641?
An essential amino acid used in specified food and nutrient applications, with the permitted use and label context depending on the product. Goodnessly rates E641 Safe, while food-category permissions and regulator conditions still apply.
An essential amino acid used in specified food and nutrient applications, with the permitted use and label context depending on the product. Check the food category, amount and full formulation rather than judging one ingredient in isolation.
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Read the FAQ →
What is L-Leucine?
L-Leucine is An essential amino acid used in specified food and nutrient applications, with the permitted use and label context depending on the product. Its function depends on the formulation and the conditions attached to the permitted use.
What's it used for?
- Providing a specified nutrient function
- Supporting a formulated food or supplement purpose
- Contributing to a defined formulation
- Appearing in products where amino-acid use is permitted
Where you'll find E641 on the shelf
You may see E641 in packaged foods where its technical function is useful and the food category permits it.
Is E641 permitted? What the regulators say
L-Leucine is listed in the checked AU/NZ and EU frameworks with conditions. Permission is conditional: category, level, identity and specifications matter.
| Region | Status | What this means |
|---|---|---|
| AU/NZ Australia & New Zealand (FSANZ) | Permitted with conditions | FSANZ lists 641 for specified food uses in the Food Standards Code. [FSANZ source] |
| EU European Union (EUR-Lex) | Authorised with conditions | The consolidated Union list includes E641 for specified categories and conditions. [EUR-Lex source] |
| US United States (FDA) | Permitted with conditions | FDA’s 21 CFR 172.320 provides a US pathway for L-leucine in specified food uses. [FDA source] |
Goodnessly rates E641 Safe within its rating system. The rating does not remove the need to consider the product category, amount or full formulation.
- No recent EFSA food-additive re-evaluation establishing a numerical ADI for E641 was located in the checked primary sources. The JECFA evaluation and current EU/US permissions were checked.
- JECFA’s 2004 evaluation treated leucine as a macronutrient and concluded that its use at current intake levels was acceptable; it did not set a numerical ADI. “No numerical ADI” does not mean unlimited use: applicable food-category and formulation conditions still matter.
- Regulatory permissions can change; confirm the primary source when a product, recipe or use is unusual.
This section is checked periodically rather than continuously — confirm the current primary source before relying on a regulatory detail.
Who might want to limit or avoid it
- People comparing additive functions across products
- People checking the frequency of this ingredient in their usual foods
- People who want to consider the whole formulation and serving pattern
Goodnessly rates E641 Safe as a practical prompt to understand the ingredient, the product and the overall formulation.
How to spot it on a label
Look for:
- L-Leucine
- Leucine
- 641
- E641
- Additive class (641)
Ingredient labels may use the name, the number, or the additive class followed by the number.
Frequently asked questions
What is E641?
E641 is L-Leucine, An essential amino acid used in specified food and nutrient applications, with the permitted use and label context depending on the product.
Is E641 permitted?
E641 is listed with conditions in Australia/New Zealand and the EU. FDA lists it for specified food uses.
What should I know about l-leucine?
JECFA’s 2004 evaluation treated leucine as a macronutrient and concluded that its use at current intake levels was acceptable; it did not set a numerical ADI. “No numerical ADI” does not mean unlimited use: applicable food-category and formulation conditions still matter.
How does Goodnessly rate E641?
Goodnessly rates E641 (L-Leucine) as Safe within its rating system.
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