Human epidermal growth factor (EGF) is a functionally versatile polypeptide comprising 53 amino acids (aa). Due to the ability of EGF to stimulate epidermal growth and proliferation, numerous research studies have been conducted to explore its potential applications in cosmetic, skin care and medication. The emergence of recombinant DNA technology has facilitated the production of a great variety of recombinant EGF (rEGF) isoforms. However, increasing evidence supports that rEGF isoforms exhibit different levels of stability and potency. This review discusses how the less bioactive rEGF isoforms may mystify the identity and even the functional properties of authentic rEGF, which shares the same primary structure as native EGF. The identity crisis, the time-consuming, costly and labor-intensive patenting and drug regulatory processes act together to result in underrating the functional applications of authentic rEGF, which have been shown to be effective and safe in promoting treatments of a variety of skin disorders such as diabetic foot ulcers (DFU).