Hi ramozk1,
I've never used toppik but have used nanogen for the last two years, although they're different brands I imagine they do the same thing!
Concealers like toppik are great if you have a substantial amount of hair to use it on! If it is used on a relatively "bald patch" it will just look like paint on your head!!
When you say it doesn't work do you mean that it's is not effective in concealing your thinning top, or that it doesn't bond to your existing hair??
I have not left my house in the last two years without being covered in nanogen (or in a hat), luckily nobody has ever noticed it! I put it on my thin areas (and on the hairline), blend it in by patting it then cover my head in hairspray to make it completely wind proof!!
Could you post any pics with no concealer on to see how extensive your loss is??
I have put some pre,post nanogen pics below!
First one is post nanogen application!