Diabetic foot ulcer (DFU) is one of the most costly and serious complications of diabetes. Treatment of DFU is usually challenging and new approaches are required to improve the therapeutic efficiencies. This review aims to update new and upcoming adjunctive therapies with noninvasive characterization for DFU, focusing on bioactive dressings, bioengineered tissues, mesenchymal stem cell (MSC) based therapy, platelet and cytokine-based therapy, topical oxygen therapy, and some repurposed drugs such as hypoglycemic agents, blood pressure medications, phenytoin, vitamins, and magnesium. Although the mentioned therapies may contribute to the improvement of DFU to a certain extent, most of the evidence come from clinical trials with small sample size and inconsistent selections of DFU patients. Further studies with high design quality and adequate sample sizes are necessitated. In addition, no single approach would completely correct the complex pathogenesis of DFU. Reasonable selection and combination of these techniques should be considered.