ive run Tren Ace and NPP...and Tren E and Deca together. It depends on the individual. I'd recommend Aromasin 12.5mg ED and Prami 0.5mg ED to make sure there are no estro/progesterone related sides. Ive also run Tren and Deca together with just Letro and didnt notice any progesterone related sides either. Everyones different, I'd tell him to have the Prami on hand just in case no matter what. If you think puffy/itchy nips are bad from estrogen sides, thats nothing compared to the leaky tits progesterone can cause.