Two Cases of Reversible Bilateral Painful Gynecomastia Induced by 1mg Oral Finasteride (Propecia)

The document reported two cases of reversible bilateral painful gynecomastia induced by 1 mg oral finasteride (Propecia) in Korea. Finasteride, approved by the FDA in 1997 for treating male androgenetic alopecia, was known to cause gynecomastia, particularly at a 5 mg dosage. However, these cases highlighted that even the lower 1 mg dosage could lead to this adverse effect. These were the first documented cases in Korea, contributing to the understanding of finasteride's side effects.