Derived from nature and boosted by science, Ellura provides the highest levels of medical grade PAC (proanthocyanidins) needed to maintain a clean urinary tract. Only Ellura is made from pure cranberry juice extract, making it both highly potent and highly effective at helping to maintain a clean urinary tract. Other supplements are made from the leftovers (skins, seeds, stems, etc.) or a blend which lack the PAC and potency to be effective. Multiple scientific studies have shown Ellura to have the most potent PAC compared to other supplements. Not all PAC are created equal. Ellura starts working within hours of taking just one capsule. Urologist recommended.