An article in
Stanford Magazine on birth control for men.
[T]he demand and need for more options are real, Lissner contends. In a 2002 survey of 9,000 men across four continents, 55 percent said they would be willing to use a new male contraceptive if it became available. "Men have quite a few motivations," she says. For one, they are held socially and financially responsible for any children they father. And as much as skeptics may argue that women would never trust men to take a contraceptive pill, faith goes both ways: Men have to trust that their female partners are using birth control consistently and correctly.
Lissner cites the best evidence that contraception remains a pressing issue in the United States: Half of all pregnancies are unplanned. As one man wrote to her, "Condoms are a nice method. However, I have a 3-year-old that proves they are not 100 percent effective."
RISUG (Reversible Inhibition of Sperm under Guidance), it seems, has progressed to Phase III trials.
Digging into the topic again, she discovered that one of the most promising methods had progressed to phase III clinical trials in India.
Essentially a "no-snip" vasectomy, the technology is called reversible inhibition of sperm under guidance (RISUG). Instead of severing the vas deferens, a doctor injects a long-lasting polymer gel that chemically inactivates sperm as they pass through. It takes effect immediately so there is almost no wait-time before men can resume sexual activity. The polymer can later be dissolved with the injection of a second chemical, meaning that, in theory, the procedure is reversible.