If you have light hair (like blonde or redhead) using any cover up is going to be very hard. Its much easier for people with black hair to use toppic and couvre, and if you do have black hair, either one will work well for you.
I am a blonde, and personally I hated toppik. I ordered 3 little tubs of the stuff and I found it really terrible. It did not conceal my thinning, and made my head look as though i had severe moulding dandruff. I wouldn't have dared walk outside with the stuff on. Also If you wanna gel your hair, then totally forget about toppik, it aint gonna happen hairspray is all that will work. All 3 of my tubs are now in the bin.
Couvre on the other hand I couldn't live without (honestly). I havn't been outside my house without couvre on for the past 8 months. It is a bit of work to get it to an undetectable level for blondes, but once you get a little bit of practice at applying it, the stuff is magic. The way i use it, is to apply it before i sleep, then in the morning wash my hair with water only (no shampoo). This is excellent at making it appear suttle and totally undetectable.
For blondes
Couvre 7/10
Toppik 1/10
Black Hair
Couvre 10/10
Toppik 8/10
Just my opinnion :wink: