The present invention provides a method of preparing a hydrogel product comprising crosslinked glycosaminoglycan molecules at a concentration Cfinal (mg/mL), said method comprising the steps of: a) crosslinking a glycosaminoglycan having a molecular weight of above 700 kDa in conditions so as to provide a glycosaminoglycan hydrogel crosslinked by amide bonds and having a Cmin (mg/mL) that is above Cfinal/2, wherein Cmin is the concentration of gel-form glycosaminoglycan in the gel when fully swollen in physiological buffer； b) subjecting the hydrogel from step a) to post-crosslinking degradation of the glycosaminoglycan backbone, thereby reducing the Cmin of the hydrogel to a value that is below Cfinal/2； and c) formulating the partially degraded hydrogel obtained from step b) to form an injectable hydrogel composition having a concentration of glycosaminoglycan molecules of Cfinal (mg/mL).
