Is it a bad belt

A guy I work with has a 1998 with a V6, The serpentine belt squeaks, the belt like 6 years old, if I squirt belt dressing it goes away but come back in 1/2 hour. Think he needs a new belt?
Thanks
Joe

if the belt is 6 years old its a good possibility.is it cracked/frayed??
good to check tensioner & pulleys when the belt is off.by turning them
see if you feel any resistance or loosness

my manual says every year get a new one. check rockauto, get em there cheap