Of the 20 essential amino acids, nine are actually essential. Of those nine, three are branch-chain amino acids (BCAAs). Leucine falls into both groups. All BCAAS are vital for building and repairing muscles, and some researchers say leucine may be the most important of all.

BCAAs got their name from their molecular structure. They are essential because the body cannot make them, but they are available in food sources. The other BCAAs besides leucine are valine and isoleucine.

Leucine performs a number of functions in the body. It helps to regulate blood sugar, improves wound healing, and produces growth hormone. But leucine is best known for its role in the muscular system, including these functions:

- Muscle Building
- Muscle Recovery
- Prevention of Muscle Loss
- Weight Control