The pharmacological treatment of osteoarthritis is traditionally accomplished with nonspecific symptomatic agents, which are generally effective only for acute symptom relief. Compounds are under investigation that might exert specific effects on osteoarthritis pathogenesis and thus induce at least a similar short-term symptomatic effect, but also control disease progression in the long term. Glucosamine sulphate (CAS 29031-19-4) reverses the proinflammatory and joint-degenerating effects of interleukin-1 by inhibiting the cytokine intracellular pathway. Clinical trials with the crystalline glucosamine sulphate formulation (CGS; dona) approved as a medicinal drug, predominantly used at the oral dose of 1,500 mg once daily, demonstrated a specific symptom-modifying effect on knee osteoarthritis over short- and long-term treatment courses. Two 3-year trials suggested that the drug also has joint structure-modifying properties and, therefore, might be useful as a disease-modifying agent in osteoarthritis.