Tranquilizer weapons for use against humans is currently impractical. Animals that are sedated this had to immediately restrained and given drugs to ensure that they do not die due to overdose (they amount of tranquilizer is really high). read more
Tranquilizer darts do exist and are widely used for sedating animals. They take a few minutes for the drug to take effect. They are not used for humans because the risk of overdose or underdose is too high. read more