Where is it manufactured?

Somewhere in USA… Also, this product is NOT free of parabens as Barielle states. It contains methylparaben and propylparaben. Barielle states that this strengthening cream adheres to their 10 Free Promise (Formaldehyde, Dibutyl Phthalate, Toluene, Formaldehyde Resin, Triphenyl Phosphate, Xylene or Camphor). But…they LIE.

Does it work with gel nails

I believe it was intended to be used on clean nails. It probably won't work on gel nails because it can't get through the gel to strengthen the nails themselves. You could probably call the company and see what they have to say. Maybe Amazon has the number.

I`m a man and yes it works for men.

Does this cream still work if you have nail polish on your nails or do your nails have to be polish-free?

I put it on my nails if they have polish but not if I have just polished them. I use it every morning as soon as I get up and before I do cleaning and dishwasher (and I use gloves for both activities.) I also use it before I go to bed after I have washed my hands. Anna