Collagen (CLG) is a natural biomaterial with high biocompatibility, biodegradability, and low toxicity, making it valuable for biomedical applications. This review discusses CLG's structure, properties, and various forms used in regenerative medicine, tissue engineering, drug delivery, and wound healing. CLG is derived from multiple sources, including pigs, cows, fish, and marine organisms, and can be processed into membranes, scaffolds, gels, sponges, films, and other forms. The review highlights the importance of preserving CLG's native structure for optimal performance and discusses challenges in modifying CLG for specific clinical needs. CLG-based biomaterials have broad applications in medicine, including wound dressings, tissue scaffolds, and drug delivery systems. Current research trends focus on improving CLG's properties through chemical modifications, cross-linking, and the development of new forms such as bioinks for 3D bioprinting. CLG's biocompatibility and ability to support cell growth and tissue regeneration make it a promising material for biomedical applications. However, concerns about disease transmission and immunogenicity, particularly with bovine and porcine sources, require careful consideration. Marine CLG is considered a safer alternative due to lower disease transmission risks. CLG hydrolysates, which are smaller peptides derived from CLG, are also being explored for oral administration and therapeutic use in conditions such as osteoarthritis and bone degeneration. The review emphasizes the importance of maintaining CLG's native structure and the need for further research to optimize its use in biomedical applications.Collagen (CLG) is a natural biomaterial with high biocompatibility, biodegradability, and low toxicity, making it valuable for biomedical applications. This review discusses CLG's structure, properties, and various forms used in regenerative medicine, tissue engineering, drug delivery, and wound healing. CLG is derived from multiple sources, including pigs, cows, fish, and marine organisms, and can be processed into membranes, scaffolds, gels, sponges, films, and other forms. The review highlights the importance of preserving CLG's native structure for optimal performance and discusses challenges in modifying CLG for specific clinical needs. CLG-based biomaterials have broad applications in medicine, including wound dressings, tissue scaffolds, and drug delivery systems. Current research trends focus on improving CLG's properties through chemical modifications, cross-linking, and the development of new forms such as bioinks for 3D bioprinting. CLG's biocompatibility and ability to support cell growth and tissue regeneration make it a promising material for biomedical applications. However, concerns about disease transmission and immunogenicity, particularly with bovine and porcine sources, require careful consideration. Marine CLG is considered a safer alternative due to lower disease transmission risks. CLG hydrolysates, which are smaller peptides derived from CLG, are also being explored for oral administration and therapeutic use in conditions such as osteoarthritis and bone degeneration. The review emphasizes the importance of maintaining CLG's native structure and the need for further research to optimize its use in biomedical applications.