Mouth numbing is a physical side effect of administering certain drugs sublingually (under the tongue) or buccally (via the cheeks and gum). The effect can be described as a distinct feeling of general numbness or tactile suppression around the tongue and mouth which can last for up to an hour after the drug has been administered.
The stimulant known as cocaine also causes numbing of the tongue, gums, and mouth when administered sublingually. Many people test the purity of their cocaine by rubbing it in their mouth. This, however, is not a guarantee of the drug's quality as it is common for cocaine to be cut with various other numbing agents and local anesthetics, such as novocaine, lidocaine, or benzocaine, which mimic or add to cocaine's numbing effect.
Compounds within our psychoactive substance index which may cause this effect include:
Anecdotal reports which describe this effect within our experience index include: