To the Editor. —In their excellent review of gonadotropin-releasing hormone (GnRH) (also known as luteinizing hormone-releasing hormone [LH-RH]) in the September 1985 issue of theArchives, Hammond and Ory 1 cite the potential advantages of GnRH over conventional gonadotropin therapy for induction of spermatogenesis as rapidity, higher success rate, greater convenience, and lower cost. They carefully note that these potential advantages remain to be confirmed in practice. I would like to comment on the latter three items. With regard to success rate in induction of spermatogenesis, there are no large series comparing GnRH with conventional gonadotropin treatment; but with the latter, the group at the National Institutes of Health has had up to 90% success rate (Richard Sherins, MD, personal communication), considerably higher than overall success rates reported with GnRH. With regard to convenience, this is obviously an individual matter. However, the GnRH pumps are somewhat finicky, requiring careful