Ayurveda has a unique concept known as polyherbalism, albeit it can be difficult to define in terms of contemporary standards. The Sarangdhar Samhita, a work of Ayurvedic literature, introduced the concept of polyherbalism to achieve better medicinal efficacy. The amount of active ingredients employed from each plant is insufficient to provide any pharmacological impact. There is evidence to suggest that crude plant extracts frequently have higher potencies than individual ingredients. Due to synergism, polyherbalism confers some benefits which are not accessible in single herbal formulations. This work is to report the method of preparation of Antidiabetic polyherbal formulation, a novel polyherbal formulation for diabetic mellitus, and to find out the active principles in the formulation responsible for the antidiabetic action. To validate the antioxidant activity of the formulation and to study the mechanism of action of the phytochemical constituents in the formulation. The polyherbal formulation is made from the ethanol extract of Gymnema sylvestre, Berberis aristate, Costus speciosa, Pterocarpus marsupium, Syzygium cumini, Picrorrhiza kurroa, Trigonella foenum, Cinnamomum verum, Alstonia scholaris and Asphaltum pure. Fingerprinting of phytochemical constituents of the antidiabetic polyherbal formulation was performed using spectroscopical (like IR and UV) and chromatographic techniques like LCMS. Biochemical assays like DPPH and SOD radical scavenging assays were done to validate its biological activity. The mode of action of phytochemical constituents against monoamine oxidase B that have a high impact on diabetes management and complications was also investigated using molecular docking. LC-MS/MS analysis of antidiabetic polyherbal formulation ethanolic extract identified 33 compounds, including the popular flavonoids and phenolic acids. Among them, 9 compounds show antidiabetic activity. Besides this, these compounds also show biological activities like anticancerous, anti-inflammatory, antiaging, antiproliferative properties, etc. The absorption bands in the UV spectra and harmonic vibrations in the IR region indicate the presence of phytochemicals like carbohydrates, terpenoids, flavonoids, saponins, and alkaloids. The dose-dependent response of the anti-diabetic polyherbal formulation demands 40 µg/mL concentration of the drug for 50% DPPH radical scavenging and 10 µg/mL for SOD radical scavenging. The docking result points out that many of the active principles in the polyherbal formulation show a significant binding affinity score than the inbuilt ligand, safinamide binding affinity value, the inbuilt ligand safinamide had exhibited a docking score of -9.014 with -74.785 kcal binding energy. While pulmatin showed a docking score of -10.533 with a binding energy of-64.220 kcal, genistein 8-C-glucoside with a docking score of -9.541 with a binding energy of 64.673 kcal and all others have a comparable docking score and binding affinity. These results point out that the polyherbal formulation is rich in antioxidant ingredients and will require less amount for high performance. The findings obtained in the present work indicate that the novel antidiabetic polyherbal formulation, may constitute a safe multi-target remedy to treat diabetes.