Ix, T/Gel is an antifungal. It keeps naturally ocurring fungi in the scalp in check. This scalp fungus (I knew the name but can't think of it now) is not a malevolent parasite, but something that is naturally present on all human scalps. This fungus can tend to cause a bit inflammatory irritation. The catch is that DHT also causes inflammatory irritation identical to that of the fungus. The irritation caused by both factors, DHT and the fungus, can have a synergistic effect and actually accelerate immune system's attack on the follicles that causes miniaturization.
T/Sal is an exfoliant. The Salicylic Acid it packs helps melt away dead scalp skin layers and improves scalp health in general. It also increases the scalps ability to absorb topicals.