L-arabinose is a naturally occurring plant sugar, but it isn't included here for sweetness — it's included because of how it interacts with digestion.
It partially blocks the enzyme (sucrase) that splits table sugar into the simple sugars your body absorbs, which can flatten the blood sugar rise after a sugary meal.
In BrainLive, it's positioned as the ingredient behind a steadier post-breakfast period, working on a completely different mechanism from the three fermentable fibers.
In this formula: L-Arabinose is one of five named actives — see the full mechanism on our how it works page.