One is a combination protocol, involving injections of Depo-Provera to prevent spermatogenesis, combined with the topical application of testosterone gel to provide hormonal support.[37][38] A similar proposal consists of yearly subdermal implant administering a synthetic testosterone compound (7α-methyl-19-nortestosterone) combined with regular injections of Depo-Provera. [39] The implant alone (without Depo-Provera injections) has been shown to already sufficiently reduce sperm count in most of the subjects given the highest tested dosage in a Phase II trial. [40] Another is a monthly injection of testosterone undecanoate, which recently performed very well in a Phase III trial in China.[41][42]