Runhaar J, Rozendaal RM, van Middelkoop M, Bijlsma HJW, Doherty M, Dziedzic KS, Lohmander LS, McAlindon T, Zhang W, Bierma Zeinstra S. Response to: 'Different glucosamine sulfate products generate different outcomes on osteoarthritis symptoms' by Reginster et al. Ann Rheum Dis. 2018 07; 77(7):e40.