Gold has been a popular ingredient in high-end skin care treatments for a while now, but there's always been a good deal of controversy over its effectiveness. (It was actually named "Allergan of the Year" in 2001 by the American Contact Dermatitis Association.) People in the medical community aren't big fans of cosmetics companies' claims about gold, but many of those companies say they've conducted studies on their own that suggest some forms of gold can be beneficial for skin firming and rejuvenation.
Colloidal gold and gold nano flakes are both cited as being more effective forms of the material, although given nanoparticles' unregulated status, safety might also be a concern. In any case, it's clear that gold as an ingredient isn't going away any time soon, and the cache of using something so precious on your skin is always going to be appealing. Have you ever used a product that listed gold as an ingredient? And what do you think about using precious metals in cosmetics generally?