DHT works in a very specific way: it binds to receptors inside the hair follicle and gradually miniaturises it.
The visible result is exactly what you're probably already experiencing — finer, flat hair with no body, a widening part, thinner temples, and shedding that nothing seems to slow down.
Here's the most important thing to understand: as long as DHT keeps working at follicle level, no product applied to the surface of your scalp will solve the problem.