To assess the suitability of collagen-furan hydrogels for tissue engineering applications, in vivo biodegradation and biocompatibility were investigated using a rat subcutaneous implantation model. Cylindrical hydrogel samples (7 mm in diameter and 2 mm in height) were prepared using formulation r2, lyophilized, and their weights were recorded. These dried samples were subsequently implanted subcutaneously into the dorsum of male Wistar rats. A total of six rats were involved in the study, with two rats per time point, and two samples per rat. After 5, 28, and 56 days post-implantation, the rats were euthanized using CO2 inhalation, and the samples were extracted for analysis of biodegradation and histopathology.