Leucine (E641)
Updated October 2, 2026
Leucine (E641) is a food additive in the “other additives” group. It appears in 725 products in our database, 232 of them sold in the US.
Quick facts
- Also known as
- E641
- E-number
- E641
- Function
- Other additives
- Found in
- 725 products (232 sold in the US)
Foods that commonly contain Leucine
Share of published products in each category whose ingredient list includes Leucine.
Popular products with Leucine
d NOVA 4 
c NOVA 4 
c NOVA 4 
NOVA 4 
NOVA 4 
c NOVA 4 
c NOVA 4 
NOVA 4 
NOVA 4 
NOVA 4 Leucine-free alternatives
Popular products from the same categories that don't list Leucine and score Nutri-Score A–C.
c NOVA 4 
b NOVA 4 
c NOVA 4 
c NOVA 4 
c NOVA 4 How to spot Leucine on a label
Look for any of these names in the ingredient list:
Related additives
Frequently asked questions
What foods contain Leucine?
In our database, Leucine most often appears in protein powders, energy drinks, dietary supplements and bodybuilding supplements.
How many products contain Leucine?
725 published products on Foodmetria list Leucine, including 232 sold in the United States. Counts come from ingredient lists in Open Food Facts and update daily.
Product data: Open Food Facts (ODbL), updated daily. Additive information is for general education and is not medical advice. Always check the package label. Our methodology.