You can reuse the diffuser pads as much as you like. You can even add different types of essential oil to the pads to create your own personal blend. When you feel it’s time to change it up, wash them with soapy water and allow to air dry. Do not put in the dryer or use a fabric softener as this may affect the pads’ ability to absorb. You may eventually need to purchase more, but initially they will last a good long time.