Technically 1-andro converts to 1-testosterone, which is not identical to testosterone.
Supplemental dhea can convert to lots of things, but generally testosterone is very low on the list.
Peoples individual metabolism of these compounds will vary, so some may find dhea mildly suppressive. But, again generally, the studies seem to indicate negligible impact on lh/fsh.
Someone like
brofessorx could give you a much more detailed chemical comparison than me.