NEEM is being tested as a contraceptive that can be injected or applied in the vagina. While the contraceptive effect of the injection is expected to last for as long as six months, the vaginal application is for use at the time of intercourse and is 1b believed to be totally effective as it kills spermatozoa in 30 seconds. The injection has been developed by the National Institute of Immunology and the application by the Defence Institute of Physiology and Applied Sciences, both in New Delhi.