A recent large scale study was conducted to measure how well the monthly injections of testosterone work as a contraceptive and how safe they really are. The study observed over 1,045 Chinese men between the ages of 20 and 45 years. The conditions of being a part of the study were that the men should have fathered at least one child in the last two years prior to the study. They also needed to be in a stable relationship before and during the course of the study.
For the first months of the study, the men were given testosterone Injections in their buttocks every month. It was found that after the administration of this treatment for 6 months, most of the men had very low sperm counts. However, it was also noted that the sperm count was not reduced in about 5% of the men in the study.
For those men on whom the injections made an impact, the treatment was continued over the next two years. However, not all men who participated in the study actually completed it. Only 733 out of 145 men completed the study. The other had dropped out of the study during its course.
During the trial, it was found that the sperm count rose again for just over 1 percent of the men. Also, nine pregnancies occurred during the course of the study. Overall, it was found that after the first year of the study, there was 1 pregnancy for every 100 men that participated. However, at the end of the second year, the pregnancy rate was fractionally higher at 1.1 per 100 men. One other interesting aspect was that the sex drive was comparatively higher in the participants of the study.
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