Fresh kava root contains on average 80% water.
Dried root contains approximately 43% starch, 20% fibers, 10-15% kavalactones, 12% water, 3.2% sugars, 3.6% proteins, and 3.2% minerals.

Kavalactone content is greatest in the roots and decreases higher up the plant.
The kavalactone component can vary between 3% and 20% of rootstock weight depending on the age of the plant and the cultivar (Lebot and Levesque 1989).

The mature roots of the kava plant are harvested after a minimum of 4 years (five years ideally) for peak kavalactone content.

For export, Kava root is classified into two categories: sliced stump (chips) and lateral roots. Most kava plants consist of approximately 75% Chips upon harvesting. Lateral roots are smaller diameter roots that look more like a typical root. A mature kava plant is approximately 25 % lateral roots. Kava lateral roots have the highest content of kavalactones in the kava plant.