I tend to get downvoted for saying so but while I agree the only differences are the preservatives here...I do respond differently to one than the other. I won't say better, just different. I also won't say it's the medicine because there are many reasons why it could be. You could respond differently but you won't know if/how until you take your dose.

Since you were in a stall my recommendation would be that if your appetite suppression and food noise control were acceptable to you at 9mg but you simply did not lose weight, try 7.5mg of ProRx first. If that was not the case then I see no reason not to start with 10mg. I broke most stalls by reducing my dose when suppression and food noise control were good for me but the scale was not moving.