GABA Side Effects: Weight, Itching, Liver, Thyroid, Heart Rate, & Gut Phenyl-GABA Side Effects

GABA side effects

GABA is one of the main inhibitory neurotransmitters in the brain, which means it helps to calm you down and relax you. That’s why people who take GABA supplements and pills tend to find that they help them feel sleepy, calm, and relaxed. However, it’s also worth bearing in mind that GABA affects many different areas of your brain and has many different effects. The GABA side effects include:

  • Gastrointestinal distress (upset stomach)
  • Headache.
  • Nausea
  • Reduced appetite
  • Constipation
  • Burning throat
  • Drowsiness/ sleepiness, muscle weakness, and fatigue
  • In high doses, some people experience shortness of breath.

If you experience any of these, you’ll want to consult your doctor before trying to self-medicate with GABA supplements again. We’ll now take a look at what the most common GABA side effects are, as well as how to avoid them.

Gamma-aminobutyric acid (GABA) is also the primary inactive ingredient in most over-the-counter (OTC) sleeping medications. This is why most people who take these medications experience sedation and drowsiness.

If you’re taking an OTC sleeping medication and experience unwanted side effects, you’re not alone. Moreover, it is a dietary supplement used for the management of mood-related conditions, such as sleep disorders, anxiety, depression, and panic disorder.


What are the GABA side effects?

There are a number of GABA side effects that can vary from person to person. These can include:

1. Upset Stomach

Some people find that GABA supplements make them feel nauseous, have a headache, or cause heartburn. This is due to the fact that GABA is an inhibitory neurotransmitter and can slow down your digestive tract by causing constipation.

Other people experience minor stomach discomfort from GABA side effects because of how it inhibits brain activity. If you experience any of these symptoms, you may want to stop using GABA supplements temporarily until your symptoms go away.

Many people also notice water retention when they first start taking GABA supplements, which can be unpleasant and uncomfortable. If this happens to you, just drink as much water as possible (6-8 glasses per day) to help with this side effect. Then, if you still notice it happening after a few days, consult your doctor about stopping the supplement altogether.

Does GABA cause stomach upset?

One of the most common GABA side effects is stomach upset. GABA is an amino acid, so it has a similar effect on your digestive system as other amino acids.

As such, taking any form of GABA orally can lead to stomach upset and indigestion. This can cause digestive system problems such as nausea, reduced appetite, and an upset stomach.

If you find that GABA causes your stomach to be upset, you will want to stop taking the supplement for a few days and see if the problem goes away. If not, then you may want to consult your doctor before resuming using this supplement.

How does GABA affect the gut?

GABA is the brain’s primary inhibitory neurotransmitter, which means it works to calm you down and help you relax. That’s why people who take GABA supplements often find that they help them feel sleepy and relaxed.

Many people have found that when they take GABA supplements, they have a higher risk for diarrhea, upset stomach, and nausea. GABA has been shown to increase intestinal fluid and electrolyte transport in the gut by increasing ion absorption from the small intestine. This can lead to more frequent bowel movements and stomach cramps if you eat a meal with high-fat content or take an antacid like famotidine (Pepcid) or calcium carbonate (Tums).

In order to reduce this risk, make sure not to eat too much food with a high-fat content (especially animal fats) during your time on GABA, and don’t drink too much milk because it will slow down digestion. Additionally, avoid taking antacids while on GABA as they slow down stomach emptying.

2. Constant Nausea

GABA side effects: Constant Nausea

One of the most common GABA side effects is constant nausea, which also includes vomiting. This is likely because GABA affects receptors in the brain that regulate vomiting, so when these receptors are stimulated, it can cause vomiting to occur.

Some people find that this nausea or vomiting only occurs when they first start taking GABA and then subsides after their body gets used to it.

If you’re suffering from constant nausea and vomiting due to your use of GABA, we recommend consulting a doctor before continuing with further use of the supplement or medication.

3. Headaches

Many people who take GABA supplements and pills to help them relax and sleep find that they get a headache as a GABA side effect. This may be because GABA affects so many different areas of your brain, so if it’s not having the desired effect on one area, it can have an impact on other parts of your brain.

A headache may also be caused by taking too much of any one of the amino acids, such as tyrosine or 5-HTP, which is why you should always speak with your doctor before self-medicating with these products.

To avoid getting a headache when you take GABA supplement pills, ensure that you are only taking the recommended dosage for your age and weight.

Additionally, try changing up how you take your supplements – some people find that taking their GABA before bed helps them sleep better and doesn’t cause any headaches.

Can too much GABA cause headaches?

One of the most common GABA side effects is a headache. If you’ve ever taken anything that works to calm your brain, like an over-the-counter sleep aid or Valium, you may have experienced a headache at some point.

That’s because your brain is so relaxed that it can’t focus on anything else and a little pressure still builds up there. The same thing can happen with too many doses of GABA. Your brain feels so relaxed that it becomes hard for blood to flow through it and this pressure could cause a headache.

Can taking GABA cause migraines?

Some people experience migraines as a GABA side effect. A recent study found that ”disturbance in the inhibitory GABA A receptor is involved in triggering the migraine aura.”

The study concluded that they were able to reduce the severity of migraines with a drug called gabapentin, which is a medication that widens blood vessels and reduces pain.

That’s why people who take GABA supplements and pills tend to find that they help them feel sleepy, calm, and relaxed.

However, this can also be problematic as too much GABA can have a negative effect on your body and brain. That’s why it’s important to consult with a doctor before starting any supplement regimen or taking any kind of medication if you haven’t already been prescribed it.

4. Sleepiness/ Drowsiness

GABA side effects: Sleepiness

GABA attaches to a protein in your brain known as a GABA receptor, it produces a calming effect– meaning you can get sleepy due to the medication. Thus, it’s important to talk to your doctor before taking GABA supplements or pills again.

Sleepiness/drowsiness is one of the most common GABA side effects, and that’s because low levels of this neurotransmitter are linked to insomnia and disrupted sleep. However, there have been studies that have shown that GABA can actually help people fall asleep more quickly and get a better night’s rest. It increases serotonin levels in the brain, which promotes relaxation.

There’s no doubt about it: sleepiness is one of the main benefits associated with taking these supplements. From an anxiety perspective, this could be considered a positive effect because it helps calm you down and relax– especially if you tend to have difficulty sleeping due to anxiety or stress. That said, high doses of GABA can cause some people to become too sedated and sleepy–so it may not be an issue for everyone.

It’s well known that taking GABA supplements can make you sleepy. This is due to the effect it has on a neurotransmitter called gamma-aminobutyric acid, or GABA. It’s one of the main inhibitory neurotransmitters in the brain, which means it helps to calm you down and relax you. That’s why people who take GABA supplements and pills tend to find that they help them feel sleepy, calm, and relaxed.

5. Reduced appetite

The initial rapid increase in astrocyte glutamate captation indicates that leptin could reduce the stimulatory effects of glutamate on hunger. Thus, some people taking GABA complain of loss of appetite. It can be related to nausea, stomach upset, and constipation or not.

Therefore, GABA blocks the hunger signal in your body when you are full so you don’t overeat. Moreover, a high dietary GABA intake (5%) significantly suppressed food intake (−30%) in most people.

The reason is that GABA is an inhibitory neurotransmitter. Thus, GABA controls the availability of energy for body use by ensuring the body has enough energy it needs to function. How it does this is by controlling the brain function to know when you are hungry and full thus reducing food intake.

Does GABA suppress appetite?

This is a common side effect of GABA, and it actually seems to work quite well. Most of the people who take GABA have reported reduced appetite as one of the common side effects.

A combination of vigabatrin and dietary GABA highly elevates the levels of peripheral circulating and brain GABA and severely suppresses food intake. The downside is that GABA can lead to weight loss, due to the depressed appetite which may not be desirable.

In order to avoid this side effect, you’ll want to take GABA supplements at the same time as your meal. This will help prevent any feelings of hunger or cravings from kicking in after you’ve eaten. It will also help with regulating your appetite so that you don’t feel like you need to eat more than your body needs.

6. Dependence/Tolerance

As with many other medications, GABA can become addictive. This is because your brain adjusts to the increased presence of GABA in your system and so it takes more and more GABA to produce the desired effect.

This is why people who take anxiety medication may find they need a higher dose over time to achieve the same effect. As a result, people can become dependent on or tolerant to this type of medication if used for long periods or without a break.

However, the dependence is not as pronounced as when you use benzodiazepines for anxiety. However, your body may get used to the different levels of GABA giving you some dependence on the medication.

7. GABA side effects- thyroid

Most of the GABA side effects are not yet well-defined and thus some people may want to opt-out of taking the supplements for anxiety. Some other people would want to get a second opinion from a different doctor on the effects of GABA on the thyroid.

Current studies have shown that GABA inhibits the release of thyroid-stimulating hormone (TSH). The hormone is released by the pituitary. GABA inhibits the release either by acting directly on the hypothalamic thyrotropin-releasing hormone neurons or directly on the pituitary.

Thus, GABAergic deficit may be deduced to be a result of low thyroid hormones. This means that thyroid hormones contribute to mood and cognition changes in hypothyroid patients. Therefore, a dose of 2 to 5 mg of GABA per day was effective in suppressing an overactive thyroid.

8. Liver side effects

There are many side effects that are associated with the intake of GABA some of which are not verified. Being a natural chemical found in the body, some of the side effects may not be factual.

Gabapentin, a gamma-aminobutyric acid (GABA) analog, has been associated with liver injury but not frequently. Moreover; the morbidity and mortality from the associated liver injury is contested. This is because some studies have also shown that preemptive treatment with GABA protected against severe acute liver injury.

It’s worth noting that GABA has infrequently been reported to cause liver injury. This may be due to the fact that GABA is an amino acid. Amino acids are processed by the liver and can put a strain on it, which is why some people experience these side effects.

GABA-mediated STAT3 signaling is known to protect against liver injury. Even though hundreds of prescription drugs are associated with liver damage, more studies need to be carried out to identify the potential liver side effect of GABA.

If you think that you are having liver problems or other side effects as a result of taking GABA, we recommend that you should stop using the supplement and contact your doctor. To avoid them, it’s important to consult your doctor before taking GABA supplements and pills as these could lead to complications.

GABA Effects on sleep and mood

It inhibits neural activity, GABA facilitates sleep, and it’s been used as a sleep aid.

GABA is one of the sleepy neurotransmitters in the brain, which means it helps to calm you down and relax you. That’s why people who take GABA supplements and pills tend to find that they help them feel sleepy, calm, and relaxed.

Does GABA affect sleep? Yes. GABA facilitates sleep, and it has been used as a sleep aid in some cases. If you have trouble sleeping at night, your doctor may recommend that you try taking a GABA supplement before bedtime to help promote a better quality of sleep for yourself.

Can GABA cause insomnia?

Insomnia is one of the most common GABA side effects when you reduce GABA intake. This is because a lack of GABA can cause the neurons in your brain to fire too fast and be unable to wind down.

GABA helps us feel calm, relaxed, and sleepy. When we don’t have enough GABA in our brain it causes insomnia as a result of our brain not producing enough GABA to make us feel that way.

If you are struggling with insomnia and think that it might be due to low levels of GABA, consult your doctor about taking an additional supplement or try taking less than the suggested dosage of your current supplement.

How to Avoid GABA Side Effects

If you’ve experienced GABA side effects in the past, you may want to try and avoid them in the future.

The first thing that you can do is speak with your doctor before taking any supplements. If you’re experiencing any of these GABA side effects, consult your physician before taking more supplements or pills.

Your doctor will be able to examine you and determine whether or not a supplement like GABA would be safe for you to take. They’ll also be able to make sure that any possible side effects are taken care of in advance.

Secondly, be aware of what other medications or supplements interact with GABA. If there are any that could increase the effectiveness of GABA or make it unsafe for you, then it might not be worth taking at all.

It’s also worth bearing in mind that things like age and hormone levels may be factors in why you are experiencing these side effects. For example, people who are younger will produce more testosterone and estrogen than those who are older.

With that said, those hormones can affect how the body reacts to GABA. As we get older, our production of hormones decreases, and as a result, we produce less GABA naturally. This can lead to problems in regulating hormones and may cause one to experience various GABA side effects.

Final Words

It’s worth noting that GABA affects a number of different areas of your brain, which is why some people experience the side effects listed below. If you experience these side effects, you’ll want to consult a doctor before taking any more GABA supplements.

What are some common GABA side effects?

Some of the most common GABA side effects experienced by people include:

  • Drowsiness
  • Stomach upsets
  • Lethargy
  • Memory problems
  • Confusion
  • Tiredness or fatigue
  • Headache
  • Nausea

You should also know that if you have an alcohol dependence disorder or have any liver disease, your body is not able to break down GABA properly and this can lead to increased adverse reactions when taking it. This is because GABA is mostly stored in the gut and the liver, as well as distributed throughout your entire central nervous system.


What are the GABA side effects?

The most common GABA side effects are sleepiness, dizziness, and nausea. As mentioned before, these side effects can be a result of taking too high doses of GABA supplements. They may also be a result of taking other medications with GABA in it. If you’re experiencing any of these, it’s worth consulting your doctor first.

Can I avoid the GABA side effects?

Some people find that they experience one or two minor side effects when taking GABA supplements or pills, but there are ways to limit this. First and foremost, start with a low dose and see how your body responds to it. If you start feeling lightheaded or dizzy after taking it for a few days, you may want to consult your doctor before continuing to take the supplement or pill. You could also try just taking half a dose in order to help limit the risk of any adverse reactions occurring.

Why does GABA make me sleepy?

GABA is meant to help you relax, which means it can have a sedating effect on the brain. The reason why some people experience these side effects is that GABA affects many different areas of the brain, so it’s possible that it influences how your brain perceives sleepiness.


Dr. David Barlow

David is a well-known researcher and author in the anxiety disorders area with extensive research on their etiology, nature, and treatment. He started the site to share his real-life experiences on the management of anxiety disorders with successful diagnosis and treatment being his motivation to write or review the content on this site.