I am very sensitive to MSG. It gives me a headache.

A quick search found this list of side-effects from MSG.

Neurological - Depression, Mood swings, Rage reactions, Migraine headache, Dizziness, Light-headedness, Loss of balance, Disorientation, Mental confusion, Anxiety, Panic attacks, Hyperactivity, Behavioral problems in children, Attention deficit disorders, Lethargy, Sleepiness, Insomnia, Numbness or paralysis, Seizures, Sciatica, Slurred speech, Chills and shakes, Shuddering