Chinese researchers may have developed an injectable male contraceptive that is reversible and has few serious side effects, according to a report published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism.
The contraceptive is a combination of testosterone in tea seed oil. Chinese researchers conducted a study of 1,045 Chinese men between the ages of 20 and 45, in which each man had fathered at least one child. Each of the men had sexual partners between the ages of 18 and 38 years old.