I want to wean off of viibryd (vilazodone hydrochloride). The sexual side effects are too hard to work with even with wellbutrin in the mix. What's a safe timeframe to wean off something like viibryd (vilazodone hydrochloride)?

It can be done fairl. Quickly, but why not talk to your doctor about how to do it?
Slowly. First off, i'm surprised you are on both the viibryd (vilazodone hydrochloride) and the wellbutrin but i'm sure it is not unheard of. Weening is variable but typically people can do it by decreasing by 1/2 every 4-8 days, or about a week. I.E., 20mg for a week, 10mg for a week, 5mg for a week than stop, much like when you started taking the medication.