For DHT, the two most common is minoxidil (Rogaine and Regaine) or finasteride (Proscar, Propecia, Fincar, Finpecia, Finax, Finast, Finara, Finalo, Prosteride, Gefina, Appecia, Finasterid IVAX, Finasterid Alternova). Sometimes spironolactone (Aldactone, Novo-Spiroton, Spiractin, Spirotone, Verospiron or Berlactone). There are different brands of each of these I put in parenthesis.
Also iron deficiency, high insulin, and thyroid (over and under active) problems can cause hair loss.