Diabetes and hyperlipidemia are among the biggest worldwide health issues and are the causative factors behind many chronic ailments and complications. Polyherbal formulations from traditional medicine hold much promise as an alternative or complement to orthodox medication. This investigation sought to compare the antidiabetic and antihyperlipidemic properties of a polyherbal drug in streptozotocin-induced diabetic rats, in addition to checking for any possible herb-drug interactions with metformin. Results indicated that the polyherbal drug lowered blood glucose levels remarkably, enhanced lipid profiles, and showed no adverse interactions with antidiabetic medication metformin. The findings indicate the therapeutic potential of the polyherbal drug in controlling diabetes and hyperlipidemia with a good safety profile. Additional clinical trials are suggested to validate these effects in human subjects and investigate the mechanisms of action of the herbs in the formulation.