There was always some doubt that he actually used it since some (few) men produce testosterone that's chemically identical (or enough so to make the current tests useless) to the artificial material, but there was never any evidence provided that Landis had that sort of testosterone.
Sounds like he's admitted using the artificial stuff.
Block packing would seem to be of much more value to the guys on the tours though.
“Block packing would seem to be of much more value to the guys on the tours though.”
I assume you meant blood, which would have given him the instant boost. Testosterone does not have that effect on the physiology.