This will depend on the type of hair loss you are experiencing and the extent of hair loss. Reversing pattern hair loss becomes more challenging the longer it goes untreated. This is related to progressive miniaturization of the hair follicles, which is driven by genetics and in some cases, a hormone called dihydrotestosterone (DHT).
While reversing hair loss is the goal of any hair loss treatment, preventing further loss of hair is also considered a goal in hair restoration.
It is important to consult with a doctor to determine if you have pattern hair loss and discuss what treatment options are right for you.