hi flux
There were intial concerns that zix would lead to systemic zinc overdose, but this was shown to be nigh impossible with the tiny amount of zinc and the relatively poor topical absorption of zix.
This then led to a discussion about follicle burnout - i.e. the concentration of zix in the follicle itself, and its effect as a copper competitor - i.e. copper deficiency in the presence of high zinc concentrations.
However, the fact that there are a number of people who've been applying zinc-based creams on their face/arms etc over a number of years, and have not noticed any follicle damage, seems to support the idea that zix is safe.
As a precaution, it would be wise to add a bit of copper once or twice a week, just to keep the levels in check. Folligen would be a good candidate for that.