I take NAC daily, even on days I use Ayahuasca or other haramala preparations - which is fairly frequently for the harmalas at least. Have had no issues even with fairly massive doses (350mg harmine +300mg THH on multiple occasions).
Pharmacologically, there should be zero interaction. Anecdotally, I've been totally fine. If anything, it seems to remedy some of the unpleasant gastric side effects.
Without growth, what's the point?
Avid gardener and Ethnobotany enthusiast