D-Glucosamine sulfate is a stable crystalline form of glucosamine that delivers sulfate ions alongside the glucosamine molecule. Unlike glucosamine hydrochloride, this form provides sulfate, which the body uses to build and maintain cartilage. The body absorbs only 10 to 20 percent of an oral dose. Taking it with food increases absorption.
People use it to ease stiff, achy joints and to maintain mobility as they age. Splitting the dose across meals helps avoid stomach upset.
Most D-glucosamine sulfate today comes from synthetic production. Shellfish allergies are rarely an issue but remain a theoretical concern with some older products. Anyone taking blood thinners like warfarin or diabetes medication should speak with a doctor before using glucosamine, since it can influence clotting and blood sugar levels.