Drop in coils last a week to 2 weeks tops. Thats just how it is. And as everyone said, its the wicking that goes bad first. Minor tweaks like juice viscosty adjustments, poking holes in the wicking, etc. may or may not extend the life of the coil head. The mesh coils now available seem to last a bit beyond two weeks but not by much. But really, the disposable coil heads are just that, disposable.