L-leucine

L-Leucine (CAS 61-90-5), also identified as E641 in food additive contexts, is an essential branched-chain amino acid used across pharmaceutical, nutritional, and food manufacturing applications. It functions primarily as a flow agent, flavor contributor, and active nutritional ingredient in finished formulations. In sports nutrition and dietary supplements, it is a core component of BCAA blends.

It supports muscle protein synthesis signaling and drives product label claims in protein powders. Pharmaceutical manufacturers use it as a dry powder inhaler excipient to improve performance. Its lubricant properties improve powder flowability and aerosolization performance in respiratory drug delivery systems. Food producers incorporate it as a flavor enhancer in savory applications and broths.

Cosmetic and personal care formulators use it in amino acid-based moisturizing systems. It contributes to skin conditioning and humectant performance in various serums and creams. The material is supplied as a white crystalline powder in food-grade, USP, and Ph. Eur. grades. FCC-grade material is standard for food and supplement applications.

The USP and Ph. Eur. specifications are required for pharmaceutical use. It is available in bulk bags and smaller packaged quantities to suit both industrial-scale and specialty formulation needs.