Gamma-aminobutyric acid (GABA) is a neurotransmitter (a chemical messenger) in your brain and nervous system. It helps calm your nerves by slowing down how often they send signals. Your body already makes GABA on its own. But you can also take it as a dietary supplement. Some foods, like kimchi and green tea, contain GABA. Others, like brown rice and spinach, help your body make more of it.

A member of DiabetesTeam asked, “What the heck is GABA, and should I take it?” This question sparked a discussion about the possible benefits of GABA, especially when taken before bedtime. Another member said, “I have a huge 200-capsule bottle, so I will try this for the next month or two before I decide whether it’s worth the $20 a bottle or if it’s just another snake oil that we wish worked.”

In this article, we’ll talk about what the research says about GABA and when the best timing is to take it.

What GABA Does in Your Body

GABA works by calming your brain. It binds to specific spots — called receptors — on your nerve cells and makes them less active.

There is another neurotransmitter, called glutamate, that does just the opposite. It makes nerve cells more active and helps them send and receive messages.

GABA and glutamate work together to keep your brain balanced. Scientists suspect that if the balance between these two neurotransmitters is off, it could contribute to some conditions, including:

• Anxiety disorders
• Mood disorders like depression
• Seizures and epilepsy
• Hypersomnia (sleeping too much)

Your body might react to GABA from food or supplements, but it’s hard for GABA to get into your brain. That’s because of a special filter in your body called the “blood-brain barrier.” This barrier blocks certain substances and germs from reaching your brain. In studies with rats, their bodies used up all the GABA before any could reach the brain.

How GABA Might Help With Diabetes

Researchers are studying how GABA might help manage some health conditions, like diabetes. Right now, there isn’t much proof that it works. GABA supplements aren’t approved by the United States Food and Drug Administration, but they’re often sold as sleep aids or mood boosters.

The research on GABA and type 2 diabetes is very limited. However, there are a few interesting studies on GABA and type 1 diabetes that suggest that research should continue.

Helping the Pancreas With Blood Sugar Control

Your pancreas is an organ near your stomach that helps control your blood sugar. It makes two important hormones: insulin and glucagon. Insulin lowers your blood sugar, and glucagon raises it.

GABA is found in parts of the body — not just the brain — including the pancreas. The pancreas has beta cells that make insulin, and these cells have lots of GABA. In type 1 diabetes, the body doesn’t produce insulin because the beta cells are damaged.

Reducing Glucagon

The first human clinical trial with GABA tested the supplement as a way to help cells in the pancreas produce insulin. The study was done on children under 10 years old who were newly diagnosed with type 1 diabetes. GABA didn’t help their bodies make more insulin, but it did lower the amount of glucagon they produced.

Supporting Beta Cells

Studies on rats have shown that GABA injections helped lower or prevent high blood sugar. GABA also seemed to help beta cells grow and survive. This led to more insulin being made. These results are promising, but more research is needed to study the effects of GABA on humans.

Lowering Inflammation

In type 1 diabetes, inflammation damages the beta cells in the pancreas. Some chemicals from your immune system, called pro-inflammatory cytokines, make your body more swollen and sore. GABA has been shown to calm down cytokines both in humans and rats. This may help lower inflammation in the pancreas.

Reducing Stress

Some evidence suggests that GABA supplements may reduce stress, but more research is needed. Although stress doesn’t cause diabetes, stress-related hormones like adrenaline and cortisol can lead to insulin resistance and high blood sugar. Some scientists believe high levels of these hormones can damage beta cells and slow insulin production.

Over time, if you don’t manage stress, it can increase your risk for diabetes complications. That’s why it’s important to find ways to manage stress.

Helping You Sleep

As mentioned earlier, GABA supplements are sometimes sold as sleep aids. Getting a good night’s sleep helps keep your blood sugar in a healthy range. The relationship between sleep and blood sugar is complicated. Poor sleep can increase your blood sugar and lead to insulin resistance. In fact, poor sleep is one of the risk factors for type 2 diabetes.

Even though there isn’t much research on GABA supplements for preventing or controlling type 2 diabetes, some people say GABA supplements might help you sleep better by slowing brain activity.

One member of DiabetesTeam shared their experience taking GABA while wearing a smartwatch to track sleep. “I did notice that, at least during the four nights I took GABA, I had more deep sleep than light sleep,” they said.

“If that trend continues, that alone would justify the supplement to me. Deeper/REM sleep provides a ton of metabolic benefits, which over time should help lower blood sugar,” they added. “Something I will certainly watch.”

What the Research Says About Timing for GABA

There isn’t much evidence about the best time to take GABA supplements. But, in one small study, 40 adults with trouble sleeping took 300 milligrams (mg) of GABA one hour before bed for four weeks. GABA appeared to help them fall asleep faster. This suggests that bedtime might be the best time to take GABA, especially if you’re using it as a sleep aid.

Research also suggests that GABA supplements might take at least a week of regular use to start working as a sleep aid.

Because GABA can make you feel drowsy, morning might not be the best time to take it.

Still, more research is needed on the best time for taking GABA, the right dose, and whether GABA has specific health benefits for people living with diabetes.

Talk to Your Doctor

Before you try GABA or any other supplement, talk to your doctor. GABA and other dietary supplements, such as magnesium, aren’t right for everyone. They might cause side effects or interact with some medications, including medications for high blood pressure.

Your doctor can help you decide if GABA supplements are safe for you and how much you should take, if any.

Find Your Team

On DiabetesTeam, the social network for people with diabetes and their loved ones, members come together to ask questions, give advice, and share their stories with others who understand life with diabetes.

Have you taken GABA for diabetes? What time do you feel is best to take GABA? Share your experience in the comments below, or start a conversation by posting on your Activities page.