No. Overdosing of GABA is very simply pointed as harmful for health. Overdose can cause different health issues with much affection for side effects. Overdose of GABA can cause less brain activity and can lead to hypersomnia or daytime sleepiness. Problems like Gastric Distress, Nausea, Diminished Appetite, Constipation, Burning Throat, Drowsiness and Fatigue, Muscle Weakness, Shortness of Breath can also be caused because of overdosage.