1,4-Dihydroxyanthraquinone, also known as quinizarin, is a specialty chemical used primarily as an intermediate in the synthesis of anthraquinone dyes. It is key in producing vat dyes that yield red-violet shades on cotton and other cellulosic fibers, offering excellent light and wash fastness. The compound also facilitates the creation of functionalized anthraquinones for electrochemical applications, such as redox mediators in organic flow batteries. Furthermore, its extended π-conjugated structure and electron-accepting properties make it promising for research in organic semiconductors and electronic materials. While not a commodity chemical, it serves niche roles in dyes, electrochemistry, and advanced materials, with limited direct use in pharmaceuticals.