Polymer solutions are essential in enhanced oil recovery (EOR) for flooding applications but are susceptible to mechanical degradation, which severely impacts its rheological behavior. In this study, we examine the degradation of sulfonated polyacrylamide (SPAM) in a flow loop simulating an oil production system with an electrical submersible pump (ESP). The effects of the non-Newtonian fluid on ESP performance were analyzed under different operational conditions of flow rate and rotational speed. The results identified that the ESP was not the primary contributor in the tested conditions, with the globe valve differential pressure as the most relevant contributor. The ESP exhibited a significant head reduction due to the solution’s effective viscosity. However, the required shaft power remained unchanged, as strong shear rates on the impeller’s external surface reduced viscosity due to the shear-thinning behavior of the solution. A model based on the first Newtonian plateau viscosity successfully estimated ESP performance and provided the shear rates within the pump. The head losses were attributed to low shear rates in the ESP diffuser and impeller channels, which can be associated with the increment of viscosity and friction losses.