Effectiveness - There has been only one unplanned pregnancy among partners of the 250 volunteers who have been injected RISUG[wikipedia] -- apparently due to an improperly administered injection. Out of the 250 volunteers who have been injected RISUG, 15 received the injection more than 10 years ago.
Convenience - There is no interruption before the sexual act.
Cost - The shot itself costs less than the syringe used to administer it, and its long term effectiveness would make it theoretically only a four or five time cost, in the entire lifetime of someone who chose to continue to be on it.
Outpatient procedure - Patients can leave the hospital immediately after an injection and resume their normal sex lives within a week.
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