While it’s uncommon to develop immunity to antiperspirants, some individuals may find that their effectiveness diminishes over time. This could be due to changes in body chemistry, product formulation, or external factors like climate or stress. If your current antiperspirant seems less effective, consider trying a different brand or formulation with a higher concentration of active ingredients. Additionally, consulting a healthcare professional can provide personalized recommendations and alternative treatment options for managing sweat and body odor effectively.