Zinc is crucial for maintaining human body homeostasis and is one of the major components of hormones, signal molecules, and enzymes. Zinc deficiency is caused by insufficient uptake of zinc from food, or caused by malabsorption syndromes, increased gastrointestinal and urinary losses, and administration of various medications. In order to test whether oral zinc administration can successfully improve zinc deficiency-related alopecia, we treated five patients with zinc deficiency-related telogen effluvium with oral zinc administration in the form of polaprezinc (Promac®). In all patients, hair loss was cured or improved. The administration of zinc for zinc deficiency-related alopecia may recover appropriate activities of metalloenzymes, hedgehog signaling, and immunomodulation, all of which are required for normal control of hair growth cycle.