I've posted about this technology previously, but things have progressed since then. From the Daily Beast:
Male Birth Control, Without Condoms, Will Be Here by 2017 By Samantha Allen
Vasalgel, a reversible, non-hormonal polymer that blocks the vas deferens, is about to enter human trials. How will rhetoric change when male bodies become responsible for birth control?
According to a press release from the Parsemus Foundation, a not-for profit organization focused on developing low-cost medical approaches, Vasalgel is proving effective in a baboon study. Three lucky male baboons were injected with Vasalgel and given unrestricted sexual access to 10 to 15 female baboons each. Despite the fact that they have been monkeying around for six months now, no female baboons have been impregnated. With the success of this animal study and new funding from the David and Lucile Packard Foundation, the Parsemus Foundation is planning to start human trials for Vasalgel next year. According to their FAQ page, they hope to see it on the market by 2017 for, in their words, less than the cost of a flat-screen television.
So how does Vasalgel work? It is essentially a reimagining of a medical technology called RISUG (reversible inhibition of sperm under guidance) that was developed by a doctor named Sujoy Guha over 15 years ago in India, where it has been in clinical trials ever since. Unlike most forms of female birth control, Vasalgel is non-hormonal and only requires a single treatment in order to be effective for an extended period of time. Rather than cutting the vas deferens—as would be done in a vasectomy—a Vasalgel procedure involves the injection of a polymer contraceptive directly into the vas deferens. This polymer will then block any sperm that attempt to pass through the tube. At any point, however, the polymer can be flushed out with a second injection if a man wishes to bring his sperm back up to speed.