L-Leucine
L-leucine is an essential branched chain amino acid that supports muscle protein synthesis and energy production. It can also be used as a nutrient.
Found In
- Energy drinks
- Dietary supplements
- Protein powder beverages
- Sports drinks
- Naturally occurring in eggs, fish, meat, milk and poultry
- Energy drinks
- Dietary supplements
- Protein powder beverages
- Sports drinks
- Naturally occurring in eggs, fish, meat, milk and poultry
Also Known As
- E641
- 2-Amino-4-Methylpentanoic Acid
- E641
- 2-Amino-4-Methylpentanoic Acid
The Beverage Bottom Line
L-leucine is authorized for use in the U.S., Europe and Canada.
This ingredient may have authorizations in countries not included on this site.
L-leucine is authorized for use in the U.S., Europe and Canada.
This ingredient may have authorizations in countries not included on this site.
International Assessments and Authorizations
FDA U.S. Food And Drug Administration
Generally recognized as safe for intended uses. (GRAS FDA-Notified, GRAS Self-Determined)
In 2010 and 2014, FDA issued no objections for GRAS notices on L-leucine.
In 2005 and 2006, dietary reference intakes for L-leucine were reviewed by the National Academies of Sciences, Engineering and Medicine.
Learn more →EFSA European Food Safety Authority
Safe for intended uses. Permitted for addition in dietetic foods.
Learn more →JECFA Joint FAO/WHO Expert Committee on Food Additives
Safe for intended uses.
In 2007, WHO published a Technical Report on Protein and Amino Acid Requirements in Human Nutrition.
Learn more →Health Canada
Safe for intended uses. Permitted as a supplemental ingredient.
In 2005 and 2006, dietary reference intakes for L-leucine were reviewed by the National Academies of Sciences, Engineering and Medicine.
Learn more →This page was last updated on 6/30/2025