How safe is RU58841? Will it cause same sides as FIN?

[cp9]

Just ordered a ton load of RU (after seeing hellouser's success from it) from Kane because I can't tolerate Fin anymore..
Anyone who had sides from fin switched to RU? If so, any success in getting rid of the sides and still maintaining/regrowing hair?
I had testicular atrophy from fin, my testes are still in bad shape and I was hoping getting off fin would solve it.
Also real scared of gyno.. none so far though.
I just want to know what I'm going to be dealing with before I start the regime.

Any knowledge on this topic would be much appreciated!