What are the side effects of GABA

GABA supplements can cause side effects such as stomach upset, muscle cramps, facial tingling, numbness in the legs, drowsiness, headaches, and minor changes in heart rate. It is important to understand that GABA, as an endogenous amino acid, theoretically should not be harmful to health. However, as with any substance, there are some risks, especially when GABA is taken in higher than recommended doses or in combination with other medications.

For calming, relaxation and better sleep, the nootropic dietary supplement GABA can be a truly miraculous solution for many. It has a mild sedative and anti-anxiety effect and allows us to simply "switch off" when things get too much.
For more information on the effects and benefits of GABA on the human body, see the blog post GABA Benefits.

But what are the side effects and dangers of GABA? Is GABA addictive or is it detrimental to health in the long run? Our blog provides answers.

The potential side effects of GABA supplements have not been sufficiently studied, so it is difficult to know what to expect. 

Gaba side effects: headache, stomach activity disorders, small hearts changes in rhythm, sleepiness


The most common side effects of GABA can include:

- Stomach upset

- Muscle cramps

- Facial tingling or numbness

- Numbness in the legs

- Minor changes in heart rate

- Drowsiness

- Headache

Side effevts from taking gaba are rare and should disappear after a few days

It is important to understand that GABA is not harmful to health - it is an endogenous amino acid. (You can read more about what GABA is here.) However, as with all medicines and dietary supplements, side effects may occur in certain cases. This is particularly important in the case of overdose or in combination with other medicines.

Side effects with GABA amino acids are rare and should disappear after a few days. However, if it persists or is very severe, you should always contact your doctor.

In addition, there is still a lack of reliable studies and research on the use of GABA during pregnancy and lactation. Caution is advised for pregnant and lactating women since GABA can affect neurotransmitters and the endocrine system, i.e., increases in growth hormone and prolactin levels [1]. Therefore, nootropics such as GABA should not be used by breastfeeding and pregnant women.

An overdose of gaba can lead: anxiety attacks, panic, insomnia


When is it dangerous to take GABA?

First of all, as with all medicines and dietary supplements, you should always stick to the recommended dose. (For more information on the use and dosage of GABA, see here).

Data showed no serious adverse events associated with GABA at intakes up to 18 g/d for 4 days and in longer studies at intakes of 120 mg/d for 12 weeks. Only a few participants reported a slight burning sensation in the throat immediately after taking GABA which ceased shortly thereafter. In some cases, the burning sensation was accompanied by brief shortness of breath. 

Additionally, intake of 5 or 10 g daily for 4–5 days resulted in increases in immunoreactive insulin and glucagon, although no change in blood glucose level was observed. Acute toxicity studies of GABA in Sprague–Dawley rats at doses of 1000 mg/kg body weight determined a LD50 >1000 mg GABA/kg body weight. A 28-day study and a 90-day study in rats determined a no-observed-adverse-effect level (NOAEL) at 5 mg GABA/kg body weight per day, the highest dose tested. 

In a 90-day study, urine volume was significantly increased in males only at the highest concentration tested, 5 mg GABA/kg body weight. However, this was not associated with other adverse effects on urinary tract function, and thus the authors considered the effect not significant. A decrease in hemoglobin levels was seen in some GABA-treated females, but this was not accompanied by anemia and was not seen in males; thus, the authors concluded that this change also was not significant. [1]. 

Because some studies showed that GABA was associated with decreases in blood pressure  (<10% change), it is conceivable that concurrent use of GABA with anti-hypertensive medications could increase risk of hypotension.

Secondly, evidence from at least one clinical study shows that the bioavailability of GABA in the brain is improved significantly when taken concurrently with phosphatidylserine, and thus GABA may interact with medicines used to treat epilepsy.

The oral administration of a mixture of GABA and L-theanine (100/20 mg/kg) to ICR mice was found to decrease sleep latency and prolong sleep duration compared to GABA or L- theanine treatment alone following an intraperitoneal injection with sodium pentobarbital. The authors concluded that GABA and L-theanine had a synergistic effect on the sleep behavior of mice. So it can interact with sleep supplements e.g. L-theanine [1]. 

Thirdly, GABA should only be taken at bedtime. Since the supplement has a mild sedative effect and promotes sleep, the risk of driving a car while taking GABA is naturally too high. The body's natural ability to react is often needed during the day, both at work and in traffic. Mental relaxation and rest are important to replenish energy reserves and to simply unwind. However, if you want to help your body relax with GABA, you need to be in a calm and safe environment, as the body's natural response to stimuli, including danger, is slowed down.

And fourthly, when buying GABA you should make sure that you choose products of extremely high quality. Our advice: it is best to order GABA safely from online pharmacies or specialized nootropic suppliers. 

Gaba and alcohol affect our neurochemistry and comlex brain functions


GABA and alcohol

The interaction between alcohol and GABA is complex. Firstly, their effects on the brain's neurotransmitters are similar. Both substances are relaxing, reduce anxiety and sometimes cause drowsiness. If both substances are used separately and in moderation, then (depending on the situation) most people should not experience any strong side effects.

Nevertheless, self-medication with GABA is by no means advisable. GABA and alcohol affect our neurochemistry and complex brain functions. The effects of alcohol and GABA can be amplified if they are used together, which can be very dangerous.

In addition, anxiety and panic disorders, addictions and sleep disorders are serious health issues. Neither GABA nor alcohol can solve the real cause, which should be addressed therapeutically and medically.

Therefore, the use of GABA and alcohol without medical supervision is not recommended under any circumstances.



GABA plays an important role in our body as a chemical messenger. However, when taken as a supplement, its role is less clear.

Some studies suggest that it may help reduce stress, fatigue, anxiety and insomnia. However, many of these studies are small or incomplete. More evidence is needed to better understand the potential benefits of GABA supplementation. 

If you are looking for natural stress relievers, it is worth trying GABA supplements, which can be purchased online. But don't rely on them to treat any underlying conditions, including severe anxiety, seizure disorders or high blood pressure.


Medical Disclaimer

The information provided in our articles is solely for educational purposes and should not be considered medical advice or instruction. No action or inaction should be taken based solely on the contents of this information. Readers should consult their health care professional on any matter related to their health and well-being. The information and opinions provided here are believed to be accurate and sound, based on the best judgment available to the authors, but readers who fail to consult with appropriate health authorities assume the risk of any injuries. The publisher is not responsible for errors or omissions.

Please be aware that different countries may have specific regulations and that this disclaimer does not replace the need for consultation with a healthcare provider before beginning or changing a treatment or supplement regimen. The information contained in this article is not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary.



Hellen A. Oketch-Rabah, Emily F. Madden, Amy L. Roe, Joseph M. Betz. United States Pharmacopeia (USP) Safety Review of Gamma-Aminobutyric Acid (GABA). Review: Nutrients. 2021 Aug 10;13(8):2742. doi: 10.3390/nu13082742. https://pubmed.ncbi.nlm.nih.gov/34444905/.


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