The amount of time that you should go in between injections of dermal fillers depends on how quickly your body metabolizes the injected substances, as well as how much filler was used and what part of the body was treated. They can end up lasting anywhere from 3 months to two years, with the shorter timeline likely including patients who are older and are using the dermal fillers to reduce the appearance of deeper creasing in the skin, and the long timeline more likely for the younger patients who are receiving the filler to provide volume to areas such as the cheeks. Your injection specialist will be able to create a schedule that works for your specific needs and lifestyle to ensure that the dermal fillers are provided frequently enough to ensure that the results will be maintained as much as possible, without over-filling the area. Having too much dermal filler injected or receiving the same injections too frequently will result in unnatural or uneven results due to the facial contours being overly round.