Chinese scientists have discovered a new method of male contraception – effective, reversible and without serious side effects. A publication of their discovery is available in the prestigious Journal of Clinical Endocrinology & Metabolism since 2009, and a number of drugs using this knowledge are now on the market. However, they should not be taken without a doctor’s prescription, because only controlled intake can lead to the effectiveness of the product. The discovery is intended for couples who cannot or prefer not to use other forms of contraception, such as female hormone pills, condoms, vasectomy, biological control, etc. Study leader Dr. Giu revealed that this is the largest study of hormonal and non-surgical male contraception in the world and included 10,045 healthy and potent men aged 25 to 45. Each of the men studied had at least one child before the start of the study, and their partners were in the same age group and with normal reproductive abilities. Men are injected monthly with 500 mg of testosterone undecanoate, an ester of the male sex hormone. The injection is placed in the gluteal muscles, where a short-term reservoir of the compound is formed. It is gradually poured into the blood vessels, with precisely defined speed and precision. NEWS_MORE_BOX The procedure is repeated for 30 months, after which the drug accumulates the effect of testosterone undecanoate and leads to the avoidance of unwanted pregnancy in 99 out of every 100 couples, without the use of other means of protection. From 5 to 10 months after stopping the therapy, the man’s fertility returns, without disturbances in sexual function. Clinical studies investigating potential “silent” or undetected effects of the testosterone compound on the cardiovascular system, prostate gland, and behavior of those treated are still underway, but side effects from the active ingredient are rare.