"In a double-blinded, cross-over study, researchers systematically evaluated oral zinc sulfate (5 mg/kg/day) for the treatment of AA in 100 patients. The first cohort was initially treated with zinc and then placebo, resulting in complete hair regrowth in 60% of patients after 3 months and maintenance for 3 months after cessation. Conversely, the second cohort was first treated with placebo and then zinc. After 3 months of placebo, 10% of patients completely regrew hair, and subsequent supplementation with zinc resulted in 67% of patients with complete regrowth. Side effects were mild, including gastric upset . Topical and oral zinc supplementation may prove to be an efficacious adjuvant for both Androgenetic Alopecia and AA treatment in patient populations that would like CAM modalities"
5mg/kg is like 450 mg Zinc sulfate a day for me. This text is inarticulate. I presume this was done on zinc-deficient subjects.