Hi Becca,
While I support many alternative therapies, one must always be careful with treatments that aren't backed by data. (as well as ones that are sometimes!)
Gold is a heavy metal. My concern would be for the potential for problems as heavy metals are known to be neurotoxic.
http://onlinelibrary.wiley.com/doi/1...1780301022/pdf
I am glad your friend is doing better but please be cautious if you pursue the colloidal gold. Gold does have medical uses for drug delivery and cancer detection but articles regarding its use for neuropathic issues were not apparent on Google Scholar. I'd hope if it was a fix for nerve problems the research community would be on it.
said with hugs,