What It Actually Is
ACV is fermented apple juice, and the compound most associated with its effects is acetic acid. Capsule forms concentrate the active compounds without the strong taste of liquid vinegar.
What Research Generally Shows
Several studies suggest vinegar consumed with a meal can modestly blunt the post-meal blood sugar spike, which is the main mechanism researchers point to for any metabolic benefit.
Why It's Dosed At 300mg
300mg of concentrated ACV extract is a standard capsule-form dose, though it delivers less acetic acid than a tablespoon of liquid vinegar would.