When you choose to purchase Kirkland Signature medications for your household, you can do so with complete confidence. All of Costco’s Kirkland Signature over-the-counter medications are the generic version of their national brand counterparts. Kirkland Signature Brand products are subject to the same manufacturing standards mandated by the FDA, just like the leading national brands. Kirkland Signature OTC items work as well as the national brands and our products also deliver significant value and savings.