Before starting supplements, ask your GP for a blood test to check zinc, iron, and ferritin levels—deficiencies are common in young men and easy to confirm. Also clarify the type of hair loss (male-pattern vs. diffuse shedding vs. patchy) with your doctor, as this changes the best approach. If you're under significant stress or have recent major life changes, that's worth discussing too, as stress-related hair loss (telogen effluvium) responds differently to supplementation.