Actually, every cycle of AAS is going to screw up your natty production. Doesn't matter what it is, it's the nature of the beast. Some are worse than others and Tren is pretty harsh when it comes to this. This is the reason for PCT. And as I've stated before, Fina is definately not a product for new users. It can be as stated very harsh and was actually, not even close to my first cycle. The process by which you convert the tren from the pellet does away with the filler your friend was referring to. Unfortunately, regardless of how it is converted, this is a very strong AAS. The main reason people go to Fina is it's easily available, nothing more.