The Research On GABA & Sleep: How Much To Take + How It Works*

Gamma-aminobutyric acid (GABA) is the human brain's main inhibitory neurotransmitter1. This non-protein amino acid neurotransmitter balances out excitatory neurotransmitters like glutamine to help get the body into a calm state.*

Our brains are filled with GABA receptors. When activated, these receptors trigger a chain reaction that reduces neural firing and brain cell activity. "GABA interaction with its receptors increases the threshold for cells to become reactive. It relaxes the cells and inhibits reactivity," explains integrative neurologist Ilene Ruhoy, M.D., Ph.D..

When this happens, our stress response dulls, our brains quiet down, and we slip into rest and relaxation mode. Exercising, eating a healthy diet, and practicing relaxation techniques are all ways to support healthy GABA levels in the body naturally. For times when you want to activate this calming response on demand—say, right before bed—you can also take a targeted source: supplemental GABA.*

To study how supplemental GABA affects brain activity, researchers out of Japan3 had 13 people drink plain water, water with PharmaGABA® (100 mg), and water with L-theanine. (PharmaGABA® is a branded version of GABA that's been well studied). They then waited 60 minutes and looked at their brains under an electroencephalogram (EEG) scan. In time, GABA had significantly increased their alpha brain waves (relaxing) and decreased their beta waves (energizing) compared to water or L-theanine.*

Beyond helping us fall asleep slightly faster, GABA may also increase the amount of time we spend in deep sleep.* A 2016 study4 found that, compared to a placebo, a PharmGABA® supplement both decreased sleep latency and increased time spent in REM sleep, an essential phase for recovery and memory consolidation, according to an EEG scan.* Follow-up questionnaires revealed that these sleep improvements were significant enough for participants to feel, note the impact.*

This clinical trial also proved that GABA in the supplemental form was effectively and quickly absorbed (peaking in the blood at 30 minutes after ingestion).

Using this existing research as a guide, 100 milligrams of GABA5 is the most commonly studied (and thus, scientifically supported) supplemental dose and should be effective for most seeking sleep support.* However, everyone is different. Naturopathic sleep doctor Catherine Darley, N.D., notes that if you don't notice an effect with 100 milligrams, you can increase the dose up to 200 milligrams, while Ruhoy has seen even higher doses—up to 500 milligrams under the supervision of a healthcare practitioner.

As such, "it is recommended that each individual speaks to their doctor first before starting supplementation to obtain guidance," Ruhoy notes.

The best time to take GABA for sleep will also likely vary from person to person. But again, we can look to the research for indicators.

The clinical trial that tested GABA's calming impact3 on the brain found that it had activated slower brainwaves after 60 minutes, suggesting that taking a supplement an hour before bed will be effective.* However, the 2016 sleep research4 found that it can kick in even faster, reaching its highest level in the blood after only 30 minutes. Whether that blood peak timing corresponds to the sleep-supportive effects (or that comes a bit after) is not known and likely varies from person to person.

Any good supplement starts with high-quality, research-backed ingredients that are present in doses that have been clinically shown to work (in this case, at least 100 milligrams).

With sleep supplements, in particular, you'll want to look for one with active ingredients that have been researched in humans and shown to be gentle on the stomach (midnight bathroom wakeups are no fun) and comes in a form that is enjoyable to take and easy to fit into your wind-down routine. (We did the legwork and found 9 that fit the bill.)

Supplements that combine GABA with other relaxing minerals and botanicals may also be effective (perhaps incrementally so given their synergistic actions) for sleep.*

Ruhoy notes that in her experience, "GABA is usually well tolerated, but some have reported fatigue, leg discomfort, difficulty focusing, weight gain, and constipation" with the supplement.

"Because GABA can slightly lower blood pressure and acts on neurotransmitters, people on blood-pressure-lowering medications or antidepressants should be cautious," adds Darley.

mbg's VP of scientific affairs, Ashley Jordan Ferira, Ph.D., RDN concludes that, "GABA, and PharmaGABA® specifically, has a strong safety profile, so while side effects or interactions are possible for certain individuals, that would be uncommon."

Ferira goes onto share that, "In the scientific literature8, a small subset of study participants report experiencing mild GI discomfort, while even fewer may experience headache. Still others report drowsiness, which might be viewed by some as a helpful benefit for sleep, not a side effect."

As always, those who are pregnant or breastfeeding should use extra caution when starting the supplement and be sure to consult a doctor first, as GABA supplements haven't been researched in these life stages.