Well this is rich. According to a study published in the Journal of Endocrinology & Metabolism, researchers at The University of Edinburgh have developed a safe, injectable, hormonal birth control for men. For 56 weeks, 320 participants received injections consisting of two hormones: progestogen, which lowers the sperm count, and testosterone, which mitigates the testosterone-reducing effects of the progestogen. This method was found to be effective for 96% of participants, which represents a major scientific development as the only forms of birth control currently available to men are condoms, vasectomies, and withdrawal. But, despite the promise of a safe, reliable, reversible birth control option for men, the study was suspended because 20 men dropped out due to the unwanted side effects:
Researchers stopped enrolling new participants in the study in 2011 due to the rate of adverse events, particularly depression and other mood disorders, reported by the participants. The men reported side effects including injection site pain, muscle pain, increased libido and acne.
AKA the same side effects that women have endured since the 1960s. Despite these adverse effects, 75% of the participants reported a willingness to use this form of birth control, but the researchers state that "the combination of hormones needs to be studied more to consider a good balance between efficacy and safety."