Okay  -  so I need a little more information here.  Are you talking about a pooch or fullness right under the chin which is usually a fat pad (submental)?  Are you talking about those thin, vertical bands under the chin running down to  the upper neck (platysmal bands)?  Are you talking about just loose skin right under the chin?   Or, the loose, slightly crepey skin all up and down the neck?  Or, the horizontal thin lines across the neck - sometimes called "necklace" lines?   I'm sure you see where I'm going!!!  These all have somewhat different solutions and age really matters here.  A prominent platysmal band in a 40 year old is very different than one in a someone who is 70. See my article on neck issues for more information.   Dr. I