The gag reflex is a natural defence mechanism used to prevent unwanted substances going into your lungs or throat. Generally, gagging occurs when sensitive parts of the back of the mouth are touched. If you are hypersensitive, then you may experience the gag reflex when you brush your teeth, visit the dentist, or perform oral sex. But your gag reflex does not have to interfere with your life or cause you panic. There are exercises you can do to improve how you react.
Relax. Your gag reflex is heightened if you are agitated or anxious, so relax to reduce how sensitive it is.
Teach your reflexes to respond differently to being touched. First, lift the back of your tongue to touch the roof of your mouth. Then, breath through your nose, while keeping your mouth open. Hold this position for as long as you can. Keep practicing so you can hold your tongue like this for longer amounts of time.
Desensitize your mouth using a toothbrush. Gently rub the roof of your mouth behind your back teeth with a soft bristled toothbrush. Do this once a day but make sure you do not gag. If you do, you are brushing too deeply inside your mouth. In this case, position the brush nearer the front of your mouth.
Continue to stimulate the roof of your mouth with the brush. Move the position of the brush further into your mouth. As you become less sensitive, this will become possible. Do this in stages until you can rub the area directly at the back of your mouth without gagging.