GABA, or gamma-aminobutyric acid, is a supplement that I occasionally take to enhance sleep. I typically take 100 to 200 milligrams of GABA, but only every third or fourth night, no more than three or four nights a week. It's important to note that GABA, like many sleep supplements, should not be taken daily. It's also worth mentioning that GABA works by increasing the activity of chloride channels, which makes cells less electrically positive and helps shut off our thinking, aiding in sleep. As always, I recommend consulting with your doctor before starting any new supplement regimen.