DHT (dihydrotestosterone) is a hormone your body makes from testosterone via an enzyme called 5-alpha-reductase. It is a normal, useful androgen with real jobs in the body - but in the scalp, for men who are genetically susceptible, it is also the main driver of pattern hair loss.
The key idea is that DHT is more potent than testosterone at the receptors it acts on, and certain follicles are exquisitely sensitive to it. That sensitivity, not the raw amount of hormone floating around, is what decides whether you lose hair.



