Gy. Zhang et al., A clinical trial of injectable testosterone undecanoate as a potential male contraceptive in normal Chinese men, J CLIN END, 84(10), 1999, pp. 3642-3647
This is a pilot dose-finding study of spermatogenic suppression using testo
sterone undecanoate (TU) injections alone in normal Chinese men. Thirty-two
healthy men were recruited. Volunteers underwent pretreatment evaluation,
then a treatment period in which group I (n = 13) received 500 mg TU, group
II (n = 12) received 1000 mg TU, and group III (n = 7) received placebo, r
espectively, at monthly intervals during the treatment period (or until azo
ospermia was achieved). Thereafter, they underwent a recovery period until
all parameters returned to pretreatment levels. Eleven of 12 volunteers in
the 500-mg TU group, and all volunteers in the 1000-mg TU group became azoo
spermic. Faster suppression of spermatogenesis was achieved in the 1000-mg
TU group. Serum testosterone increased significantly in the higher dose gro
up at weeks 8 and 12, but remained within the normal range. Mean serum LH a
nd FSH were profoundly suppressed by both doses to undetectable levels at w
eek 16. TU injections did not cause a significant change in high density li
poprotein cholesterol levels. No serious side-effects were found. We conclu
de that both dosages of TU can effectively, safely, and reversibly suppress
spermatogenesis in normal Chinese men.