A pesar de / Pese a

A pesar de / Pese a
 

I know that a pesar de means despite, but I also see pese a. Are they
interchangable? I know pese a is subjunctive and wonder if it should
used only under certain circumstances.

The two are equivalents and can be freely interchanged.

a pesar de (que) = pese a (que)

I agree with Rusty. Also, it seems to me that "a pesar de (que)" is used more frequently than "pese a (que)".

Both words are acceptable and majory of the times the words are interchangable in the same mean of the two words for example you can to say A pesar de las cosas la situacion en el pais no cambia, or you also say Pese a la situacion del pais las cosas no cambian, they are both mean the same in the Spanish.