Vasalgel

Vasalgel is a non-surgical, reversible alternative to vasectomies with fewer side effects. It involves injecting a gel that allows sperm to pass through but depolarizes their lipid bilayers, spilling the genetic material out before it ever leaves the man (unlike vasectomies, there is no build-up or back pressure). It is flushed out with a baking soda and water solution, and can be reversed at any time (clinical trials have been running in India for 20 years). The procedure simply involves an injection in each testical, so the recovery time is barely two weeks. In the US, a variation has been in clinical trials and seeking FDA approval for 2 years (as of 2016).

http://www.parsemusfoundation.org/projects/vasalgel/