GABA, or gamma-aminobutyric acid, is a popular supplement for the relief of anxiety and insomnia. Until recently, I was not recommending it to my patients. There are no scientific studies showing that it works. So why did I start recommending it? A report by a single patient, or as we say in scientific literature, an N of 1.

This 65-year-old woman had been suffering from anxiety from a young age. When her summer camp friends would write down everyone’s most common sayings, hers was, “I am so nervous”. This sense of anxiety persisted throughout her life. She is a successful career woman with a loving family. After a death in her family, she started seeing a psychologist who suggested taking GABA for insomnia. Within days, she was overcome by a sense of calmness she never experienced in her life. It’s been several months now and she remains calmer than ever before.

Certainly, this could be a placebo effect. In addition to the lack of controlled clinical trials, it is not even clear if GABA gets into the brain by crossing the so-called blood-brain barrier (BBB). It is possible, however, that it does not have to cross BBB. There is evidence that GABA may work through the enteric nervous system (ENS) – nerve endings lining the intestines. Both GABA and its receptors are widely distributed in the gut. Certain probiotics such as Lactobacillus and Bifidobacterium were found to increase GABA concentrations in the ENS. Probiotics have been shown to improve mood. This effect may be occurring through the vagus nerve. Vagus nerve is a large nerve that connects the intestines and all internal organs with the brain. It was somewhat of a surprise that vagus nerve stimulation at the neck level was proven (and FDA-approved) to relieve refractory depression and epilepsy.

GABA has been a popular supplement for many years. This obviously does not prove that it really works. However, it is very safe and relatively inexpensive. I would consider trying it before taking a prescription drug for anxiety or insomnia. Those can have significant side effects and in a 65-year-old may increase the risk of Alzheimer’s disease. And I always recommend regular exercise and meditation before any supplements.