An ionic hair dryer dries hair more quickly by producing millions of negative ions that more efficiently break down water molecules than neutral heat can. The risk of heat damage is also reduced when using an ionic hair dryer.
The negative ions emitted by an ionic hair dryer also reduce static cling, which is the build-up of positively-charged ions. Static cling, frizz, frayed hair cuticles and dry hair are all symptoms of heat damage. The positive effects of ionic hairdryers do not last after drying is complete. For example, hair is not shinier because the negative ions were somehow absorbed, but because the hair was blasted with heat during drying for a shorter period of time.