The dermal filler used in clinic is temporary, not permanent, and over time your body will metabolise the filler naturally. Therefore, typically one sitting of dermal filler will last around 2-3 months, after that you will require a top up to sustain the volume and shape of your lips. From there, most clients will only require a top up every 4-6 months to maintain your results. Please bare in mind, the longevity of your dermal filler depends on your lifestyle.