HA fillers can work well for treating next skin laxity. Robust HA fillers injected properly on the sides, for example, can be used to lift, pull and refine the contours of the neck, and resilient, low viscosity, cohesive HA fillers can be used to improve the appearance and skin quality of the central portion of neck. Treatment generally should take no more than a fifteen minute session in experienced hands and engender little to no significant downtime. However, these are advanced injection technques that should not be left to the hands of novice injectors accustomed only to using simple Juvederm or plain Restylane for smile lines. These are advanced injection techniques and you would be wise to consult an experienced, board certified cosmetic dermatologist filler expert. Hope this helps and best of luck.