Oral cyclosporine was effective in the DEBR model for alopecia areata. All rats had a full pelage by 5 weeks of treatment with 10 mg/kg/d, 5 d/wk for 7 weeks. Studies in humans also have proven efficacy with doses of 6 mg/kg/d for 3 months in 6 patients. All patients experienced regrowth, and cosmetically acceptable regrowth was seen in 3 of 6 patients. Unfortunately, all patients relapsed within 3 months of discontinuation of cyclosporine. No evidence indicates that CsA can prevent hair loss during an active episode because reports have described patients taking CsA who developed alopecia areata while they were under treatment for unrelated conditions.