Yes Spiro will block your T, however it won't stop all of it and DHT is much stronger than the base testosterone that it is converted from. The fin basically binds where the DHT normally would and thus breaks the strangle hold on your hair. I was on E and Spiro for several months however I wasn't seeing the improvement I was looking for in my hairline, after talking with my doctor we decided to give fin a try, now three months in after adding it and I'm starting to shed hairs like crazy, which is a sign it's kicking in and I'm seeing regrowth in my temple area. Now I'm not sure where you are, however in the USA generic fin is $9 at target for a month's supply.