Can You Take L-Isoleucine and L-Valine Together?

May affect absorption

The short answer

L-Isoleucine and L-Valine are both BCAAs sharing the same LAT family of transporters. When taken individually rather than in a balanced BCAA formulation, they compete for intestinal and BBB transport.

How to arrange timing

When supplementing individual BCAAs, separate L-Isoleucine and L-Valine by at least 1 hour for optimal absorption.

Reference

Reference noted for this combination: Fernstrom JD. Branched-chain amino acids and brain function. J Nutr. 2005;135(6 Suppl):1539S-1546S.

Important context

Whether supplements suit you together also depends on dose, product formulation, health conditions, and medication use. Ask a doctor or pharmacist first if you take medication, are pregnant or breastfeeding, or have a chronic condition.