Best GABA Supplement

If you’re frequently feeling stressed, it may help to learn you aren’t alone. According to a 2023 Gallup research report, over 50% of American adults reported feeling stressed the previous day — and this number has been steadily increasing.1 Stress can have a significant impact on your health,2 and with health problems being one of the biggest stressors across age groups, it becomes apparent how stress can lead to a vicious cycle that dramatically affects your quality of life.29

In times of chronic, low-level stress, whether it’s from a busy job or lack of sleep, it might help to turn to gamma-aminobutyric acid, or GABA, one of your body’s own best building blocks.3 GABA is an amino acid and the primary inhibitory neurotransmitter (one that blocks or prevents signals from being sent) in your brain.57 It’s taken as a supplement for many reasons, with the overarching goal of helping you feel more centered throughout the day. We’ve researched, found, and tested the top GABA supplements so you can determine which one will help you the most.

If you’re in a hurry, check out our top recommendations for the best GABA supplements below.

Summary of recommendations

• Best overall: Thorne PharmaGABA
• Best budget pick: NOW GABA Supplement
• Best for bulk purchases: Nutricost GABA Powder
• Easiest to take: Quicksilver Scientific GABA + L-Theanine
• Best with additional ingredients: Source Naturals Serene Science GABA Calm
• Strongest option: Pure Encapsulations GABA

Over the past two decades, Innerbody Research has helped tens of millions of readers make more informed decisions to live healthier lifestyles.

For our review of the best GABA supplements, we spent over 100 hours reading and analyzing 50+ scientific journals detailing various studies, trials, and information about this important neurotransmitter — including important details on synthetic GABA’s safety and efficacy. We also investigated top supplement manufacturers and hidden gems to ensure our choices are truly recommendable.

Like all health-related content on this website, this review was thoroughly vetted by one or more members of our Medical Review Board for accuracy. We’ll monitor the latest research and shifting product options for GABA supplements to ensure this guide stays up-to-date.

To best understand how GABA supplements compare, we judged them in four categories: how safe they are, how well they work (including the potential behind any additional ingredients), how much they cost, and how convenient they are to take.

Safety is vitally important, especially since supplements aren’t regulated by the FDA in the same way as prescription medications. Effectiveness matters a lot, too, of course — a supplement isn’t worth your time if it’s not actually doing anything to help you. Cost and convenience are also worth considering, but most GABA supplements cost between $20 and $40, and convenience can be highly subjective, so they weren’t as make-or-break for our decisions.

Safety

Winner: Thorne PharmaGABA

GABA as a supplement should be generally safe for most healthy adults who aren’t pregnant or breastfeeding. GABA can alter certain hormones that could negatively impact a fetus or newborn, like growth hormones and prolactin.19

However, those who regularly drink alcoholic beverages, take anticonvulsants or anxiolytic (anti-anxiety) medication, or have low blood pressure (or are taking blood pressure medication) should not take GABA, as the interactions could be dangerous. And, importantly, those on an MAOI (a classical antidepressant) should avoid the Source Naturals GABA Calm lozenges, as the mixture of tyrosine and an MAOI can spike blood pressure, potentially leading to a heart attack or stroke.

Now, the FDA doesn't regulate supplements in the same way as prescription drugs. This means there isn't a reliable validation process supplements have to go through before hitting the shelves. Instead, consumers have to rely on the safety information that the company shares. When investigating the safety of these supplements, there are a few factors that we keep an eye out for:

• GMP or cGMP certification (indicating compliance with Current Good Manufacturing Practices) and FDA-regulated laboratories (meaning they’re made in safe environments)
• Independent third-party testing, which provides unbiased peace of mind the supplement truly contains what it’s supposed to and doesn’t contain contaminants
• Safe doses of ingredients in an appropriate therapeutic range

All of our top picks for GABA supplements use safe doses and are manufactured under GMP- or cGMP-compliant conditions, and all but one are subjected to extensive third-party testing. NOW is the only company from our top picks that uses in-house testing, but this doesn’t make its supplements unsafe. NOW’s labs are certified to ISO/IEC 17025 standards, which, according to ISO’s website, ensures “the accuracy and reliability” of a lab’s “testing and calibration results.” While this is impressive in its own right, we still prefer it when companies have an unbiased third party testing their products.

Three of our picks — Thorne, Nutricost, and Pure Encapsulations — stand out for safe testing due to their NSF certifications. Obtaining and maintaining NSF certification means companies must undergo random, unannounced plant inspections and thorough product testing and retesting.30 However, Thorne goes beyond just NSF certification and is also GMP-certified by Australia’s Therapeutic Goods Administration (TGA). That’s impressive because, unlike the FDA, the TGA does actively regulate dietary supplements (which it refers to as “complementary medicines”).31 32

Additionally, PharmaGABA (used by Thorne and Quicksilver Scientific) is Generally Recognized as Safe (GRAS) by the FDA as a food ingredient, and it’s regularly seen in GABA research studies.8 One 2014 study of PharmaGABA supplementation in rats found no adverse effects nor any signs of toxicity. This study used doses up to 2,500mg per kilogram of the rats’ body weight, which is equivalent to about 34,014mg (34g) of GABA for a 180lb human adult.25 However, we don’t recommend taking nearly that much GABA, as human studies using similar doses are few and far between (and older; the most recent study evaluating short-term use of a large dose, 18g, was over 40 years ago).21

Effectiveness

Winner: Thorne PharmaGABA

Thorne’s PharmaGABA is the gold standard. PharmaGABA is made through fermentation using Lactobacillus hilgardii. It has been used in several successful clinical studies, including one on its impact on promoting sleep and a separate case study on its potential to calm the symptoms of bipolar disorder with psychotic features and suicidality.23 That case study even mentions Thorne’s PharmaGABA by name, noting that 2-4 of the 100mg capsules (200-400mg total) taken as needed may help relieve anxiety.24

PharmaGABA is also used in Quicksilver Scientific’s GABA + L-theanine liposomal liquid, but the liquid form (or a powder, like Nutricost’s GABA) can be more difficult to dose accurately than a pre-measured pill. Not getting a consistently equal dose could ultimately affect the long-term efficacy.

When it comes to GABA supplements that contain additional ingredients, it’s worth looking for one that contains some of the amino acids and vitamins that can help the body create and enhance the effects of GABA, such as:

• Glutamate (which makes GABA)
• Vitamin B6 (which helps turn glutamate into GABA)
• L-Theanine (a precursor to serotonin, which helps to regulate neurotransmitters)
• Glycine (a fellow inhibitory neurotransmitter)4
• Taurine (a GABA agonist)5
• L-Tyrosine (a precursor to dopamine, which boosts the cognitive effects of GABA)6
• Magnesium (can regulate cortisol levels and promote the release of GABA)36

Out of our top picks, Source Naturals Serene Science GABA Calm lozenges stand out. Not only do they have 125mg of GABA, but they also contain:

• Glycine (50mg)
• L-Tyrosine (25mg)
• Taurine (20mg)
• Magnesium (5mg)

Combining GABA with glycine maximizes the amount of inhibitory action you’ll see,4 L-tyrosine improves the level of dopamine (the “happiness chemical” that also assists with focus and concentration),6 taurine supports GABA’s calming effects,5 and magnesium can reduce stress or anxiety by balancing your cortisol and boosting GABA.36

Cost

Winner: Nutricost GABA Powder

Even though Nutricost GABA Powder isn’t our best budget pick, there’s a good reason why it’s our winner for cost — it contains 1,000 servings of 500mg GABA for $28.95, meaning each serving is only about $0.03, and those 1,000 servings should last you a little over two and a half years. Nutricost also offers a subscription program to take 20% off, reducing the cost to only $23.16, or roughly $0.02 per serving.

So, why isn’t Nutricost our best budget pick? Because it still costs more up front than NOW’s 500mg GABA capsules. A 100-count bottle of NOW costs just $13.99. It won’t cover you for multiple years, of course, but it will last you a solid three months. And opting for the 200-capsule option is only $25.99, which is still about $3 less than non-subscription Nutricost GABA Powder.

If you’re looking for immediate savings, NOW’s GABA is the way to go. But if you can spend a little bit more at the outset and would prefer long-term savings by buying in bulk, then Nutricost’s powder could be ideal for you.

Also, if you’re not a fan of pills or can’t swallow them, another relatively inexpensive option to consider is Source Naturals GABA Calm lozenges, for which a 120-count bottle costs around $19. The only drawback is that each serving contains only 125mg of GABA, significantly lower than NOW and Nutricost’s 500mg.

Convenience

Winner: Thorne PharmaGABA

Convenience can be tricky to judge — something that’s convenient for one person may be the exact opposite for someone else. Since it’s such a subjective criterion, we gave the most weight to some of the more objective factors, like the availability of subscription or auto-ship options.

Thorne PharmaGABA is our winner for convenience for several reasons:

• It’s the only product on our list that’s available in more than one dose (either 100mg or 250mg per capsule), providing flexible dosing options for people who may need more or less GABA to see positive effects.
• Thorne products can be purchased both online and in some brick-and-mortar locations.
• A subscription option is available, with auto-ship intervals of once a month, every 45 days, or every two, three, or four months.
• Supplements purchased directly from Thorne or one of the company’s authorized resellers are covered by a 60-day satisfaction guarantee.

Some of these qualities apply to our other picks, too — NOW and Nutricost supplements can also be found in stores; Quicksilver Scientific, Pure Encapsulations, and Nutricost offer subscriptions; and both Nutricost (60-day) and Quicksilver Scientific (45-day) offer satisfaction guarantees.

When it comes to subscription intervals, however, we feel that Nutricost’s could use some improvement. Thorne, Quicksilver Scientific, and Pure Encapsulations all have customizable delivery intervals, like every 30 days or every few weeks or months. Some of Pure Encapsulations' authorized resellers even let you select an exact number of days (if you wanted your GABA delivered every 73 days, for example, you could set it that way). Nutricost, on the other hand, only allows deliveries every 30 days. That wouldn’t be a problem for the average supplement that only provides about a month’s worth of product, but Nutricost’s GABA powder gives you a whopping 1,000 servings, or over a two-year supply. Subscribing to this powder for four months would give you enough GABA for the next ten years.

Because of Nutricost’s strict interval, it’s not very practical or convenient to subscribe to its GABA powder, especially if your orders run the risk of expiring before you ever get a chance to use them. However, the subscription is easy enough to cancel after your first order if you want to take advantage of the 20% off savings.

Finally, for those who can’t swallow pills (or would prefer not to), Quicksilver Scientific’s liposomal liquid or Source Naturals’ lozenges could be a convenient, easy-to-take alternative. The former suggests holding four pumps of liquid under your tongue for about 30-90 seconds before swallowing, while the latter requires letting a peppermint- or orange-flavored lozenge (about the size of a standard shirt button) dissolve in your mouth.

To help you understand some of the differences between our favorite GABA supplements, we’ve put together a quick chart breaking down some of the most important aspects of each one.

*Note that you can’t purchase Source Naturals’ Serene Science GABA Calm lozenges from the company’s official website, so you’ll have to order through a third-party seller. Costs, subscription programs, bulk order capabilities, and shipping prices vary depending on which platform you use. The costs we listed in the chart are the suggested prices from the Source Naturals website, but the average price we’ve seen online (from sellers like iHerb) for the 120-count lozenges is around $19 (or about $8 less than the suggested price).

Your neurons send information across your brain through action potentials, which are electric charges that zip down a neuron and tell it to open its sodium and potassium channels. All neurons can be adjusted to be either more likely (excitatory) or less likely (inhibitory) to set off an action potential by opening or blocking ion channels. GABA is responsible most of the time when a neuron is inhibited, reducing the amount of information sent through your brain.

GABA is an amino acid and the most important inhibitory neurotransmitter in your brain. It’s found in up to 50% of all neurons across the brain, central nervous system, and peripheral nervous system.26

Since GABA inhibits information across your entire brain, it has a wide range of effects on all aspects of your life, such as:

Anxiety disorders,33 epilepsy,34 and insomnia are common disorders related to having too little GABA in your body.35 When your GABA is low, your neurons may fire irregularly, causing seizures. Your brain may also have insufficient receptors to pick up enough GABA, leading to a lack of control in firing rates, often a biological cause of generalized anxiety disorder.

How is GABA made?

GABA is naturally made by your body from glutamate, the major excitatory neurotransmitter, using vitamin B6 (which is likely why NOW adds B6 to its GABA supplement). However, you can get GABA from outside sources other than supplements.

The average person ingests 80-120mg of GABA daily from food alone.8 Fermented foods are one of the best sources of dietary GABA.37 In fact, it’s a by-product of foods that have been fermented with Lactobacillus bacteria, which include non-pickled items like:

• Yogurt
• Cheese
• Sauerkraut
• Kimchi
• Miso
• Cocoa
• Kefir
• Tempeh

Lactobacillus is a genus of common probiotics that creates large amounts of GABA as a protective feature to maintain their productivity in high-acidity environments.9 This also might explain why GABA is so prevalent in the gut, as Lactobacillus is one of the most common gastrointestinal (GI) and vaginal bacteria.10

The trick? Knowing how much GABA you already have. “Currently, there's no widely available test to measure GABA levels in the body,” notes Dr. Matt Segar, MD, a member of our Medical Review Board. And low GABA levels aren’t a deficiency like you might have with a vitamin or mineral.

Peripheral GABA is a term that describes places in your body that can create GABA or be influenced by it outside of your brain. There are GABA receptors in your central nervous system (which includes your brain and spine) and your peripheral nervous system (all nerves outside of your central nervous system).11 While there's still a lot to learn about how GABA works in the human body, there are a few areas we know GABA directly impacts:

The GI tract

GABA receptors can be found in your GI system, giving a whole new meaning to “gut feeling.” Research suggests that the microbiota found in your gut can influence your mood, cognitive functioning, and behavior, likely through their interactions with GABA receptors.12 This is another reason why your gut microbiome’s health is so important.

Some bacteria, like Lactobacillus and Bifidobacterium strains, can even produce GABA.13 14 For example, PharmaGABA — used by Thorne and Quicksilver Scientific — is made using Lactobacillus hilgardii.

One recent study looking at supplementary GABA in crabs showed that giving them small amounts of GABA supplements increased their average food intake and improved their digestive capacity.15 GABA supplementation could have a similar effect in humans, considering that crabs have similar blood-brain barrier mechanisms and GABA receptor spreads.

And a 2017 study found that cisgender women who have eating disorders have lower-than-normal levels of GABA.16 This means that GABA might work alongside other appetite-related signals to regulate your food intake and influence your perception of taste. While there’s still a lot of research to be done, it’s clear that the GI system has a deeply entangled relationship with GABA.

Progesterone

A metabolite of progesterone called allopregnanolone acts on GABA receptors; the higher your progesterone level, the better your GABA function. Scientists believe a dysfunction or issue with how progesterone acts on the GABAergic system is one of the reasons that PMS and premenstrual dysphoric disorder (PMDD) happen.17

A more recent 2023 review on the topic found that certain GABA receptors in cisgender women with premenstrual disorders (like the aforementioned PMS and PMDD) have a “reduced reactivity” to allopregnanolone. The authors suggest this could also be a cause of postpartum depression, but more research is needed.38

Human growth hormone and protein synthesis

Experts have known since the 1980s that GABA influences how much human growth hormone (HGH) a person makes and how well the body processes it. And since HGH builds, repairs, and maintains your muscles, GABA supplementation may be able to help those looking to get fit.

When you have a deep, restful night of sleep, your body is better at making more HGH during the night. Your sleep quality has a significant impact on how much your exercise impacts your body, and since GABA has a huge influence on your sleep, it makes sense that it would also affect how you make HGH. It can also increase the amount of HGH you have circulating in your body during the day.

A study from 2019 found that when otherwise healthy men supplemented their diets with 100mg of GABA along with whey protein, they increased their muscle mass significantly more than those who just took whey protein exclusively.18

However, an older, smaller study from 2008 had some different results. It investigated the effects of a 3g dose of GABA on the growth hormone levels and exercise performance of 11 healthy, “resistance-trained” men. While there was no difference between the placebo and experimental groups in terms of exercise performance, the group that took GABA saw a 400% increase in growth hormone levels at rest and about a 200% increase with exercise.39

Ultimately, these findings mean that GABA does appear to influence growth hormone levels, but it’s unclear whether or not it can boost exercise performance.

Supplemental GABA almost always comes in an ingestible form: a capsule, pill, powder, or oil. When you take a GABA supplement, it gets broken down by your stomach into its chemical form.

We don’t know exactly how GABA gets into the rest of your body after being dissolved in your stomach. If it works like other ingestible supplements, it’s either uptaken by GABA receptors in the GI system or moved into the bloodstream to cross the blood-brain barrier. However, as we explain below, even that explanation gets complicated fast.

GABA and the blood-brain barrier

In order to protect your brain from outside influences, your body has a highly selective barrier between your blood and central nervous system. This physical barrier in specific blood vessels is called the blood-brain barrier (BBB). The BBB keeps things that don’t need to reach your brain from getting in.40 It's pretty challenging to pass through unless assisted by a transporter or receptor, which is a unique sort of protein designed to pass one particular kind of molecule up to the brain.

There’s a lot of debate about whether or not GABA passes through the BBB. That is, we don’t really know whether GABA works through the brain or through the central or peripheral nervous system — or, to a broader extent, if it really works when taken supplementally.

A 2020 systematic review on GABA for stress and sleep in humans delves into the mixed findings on this topic. Some studies from the 1970s suggest that supplemental GABA is wholly unable to cross the BBB, while others from the ’80s to the early 2000s suggest anything from small to substantial amounts can get through.41 Two studies mentioned in the review — a 2008 study with 13 human subjects and a 2012 study with 63 — used electroencephalogram (EEG) tests to measure brainwaves in response to biosynthetic GABA, and the researchers found evidence that GABA could reach the brain.42 43 (It’s worth mentioning that the 2008 study used PharmaGABA, the form used by Thorne and Quicksilver Scientific.)44

Basically, whether or not GABA can cross the BBB is unknown at this point, but research on supplemental GABA for concerns like anxiety and stress is promising. This means that even if GABA doesn’t permeate the BBB, it still may be able to help you.

The FDA and the United States Pharmacopeia (USP) — a guidebook describing all drugs, chemicals, and pharmaceuticals — both say that GABA supplements are generally safe when used as directed, but there aren't clear guidelines as to what constitutes a safe dose of GABA.8 19

The FDA notes that doses up to 750mg of PharmaGABA (made using a strain of lactic acid bacteria called Lactobacillus hilgardii K-3) is safe to take as a digestible ingredient, but the USP recommends no more than 125mg of GABA per day for up to 12 weeks.20 Most GABA supplements come between 100mg and 750mg for a daily dose, which makes sense considering the aforementioned suggestions.

On the other hand, some data from older studies suggests that you can safely take up to 5g (5,000mg) of GABA without experiencing adverse side effects (though consumers often report that side effects start at around 1g, or a bit less, per day).21 Indeed, in a study from 1980 that gave people up to 18g of GABA and GABA-creating compounds for four days, some participants experienced breathlessness, burning sensations in their throats, elevated growth hormone levels, and an enhanced response of prolactin to hypoglycemia, but none experienced “overdose” symptoms.21 (We seriously recommend against taking anywhere near this much GABA unless explicitly directed to by a doctor.)

You’ll have to experiment to find the ideal GABA dose for you. Though it’s a relatively safe supplement, taking too much can be uncomfortable or even risky, so start at the lowest recommended dose (or even less, if you’d prefer). As with all supplements, this should be done under the supervision of a medical professional who will know if GABA is safe for you.

GABA-based prescription medications and drugs

If you’re currently taking any anxiolytic (anti-anxiety), hypnotic, sedative, or anti-epileptic prescription medications, we recommend getting approval from your doctor before taking a GABA supplement, as these drugs often increase your total GABA. Examples of these medications include, but aren’t limited to:

Alcohol also acts on GABA receptors — and so do some illegal drugs like gamma-hydroxybutyrate (GHB). The influence these drugs have on GABA receptors can explain many of their behavioral effects, like a lack of inhibition and lower perceived stress levels. If a drug has a sedative or “depressant” effect, there’s a good chance it works by increasing the amount of GABA in your brain.

If you take a prescription drug that alters GABA levels, it’s vital to speak with your doctor and make sure it’s safe before adding a GABA supplement to your regimen.

Potentially dangerous situations

GABA supplements are generally safe for most healthy adults (who aren’t pregnant or breastfeeding) when used as directed, but they — like most supplements — aren’t without their risks.

If you have low blood pressure or take hypertensive medication for high blood pressure, you should be careful about taking GABA supplements. GABA can have hypotensive effects even at low supplemental doses, dropping your blood pressure and slowing your heart rate.22 No studies have shown these effects to cause serious harm, but low blood pressure can be deadly.

Supplemental GABA can sometimes make breathing feel difficult — often a sign that you’re taking too much GABA, given how GABA interacts with the peripheral nervous system. This might feel like tightness in your chest, a burning sensation, or overall shortness of breath. Though it may pass quickly, it’s an important — and somewhat distressing — sign to pay attention to.

Also, it’s generally unsafe to take a GABA supplement if you:

• Regularly drink alcohol or plan to while you use the supplement
• Take anti-anxiety or anti-epileptic medication
• Take depressive party drugs like GHB

Remember, unless you have a doctor’s approval, you should not take a GABA supplement if you take another medication or recreational drug that influences GABA. Too much or too little GABA circulating in your brain can lead to various health issues, including some severe ones.

Your brain also gains tolerance to GABA relatively quickly — it stops making as much naturally when you supplement it with an outside source. That’s why certain GABA-altering prescriptions, like Xanax, are prescribed for short-term use only and can be dangerous if stopped abruptly (tapering off with the help of your doctor is recommended).36 Off-kilter GABA levels can lead to low blood pressure and hypersomnia or daytime sleepiness.7 In extreme cases, it can cause strokes, seizures, and difficulty taking in enough oxygen to meet your cell's needs, leading to death.

If you think that you have an anxiety disorder and want to take a GABA supplement to help improve your symptoms, we recommend doing so under the care of a psychiatrist or other medical professional familiar with psychiatric concerns.

A GABA supplement might be the right for you if you’re struggling with mild amounts of chronic stress or sleeplessness and need a bit of a nudge in a calmer direction. Your medical provider might also recommend a GABA supplement if you struggle with mild anxiety or depression and don’t want to begin an antidepressant just yet.9 Keep in mind that you should always start a supplement under the guidance of a doctor since there are hundreds of ways that medications and supplements can interact.

Other populations who might benefit from trying a GABA supplement include:

• People with PMS or PMDD
• People with chronic pain
• Amateur athletes

Who should look elsewhere?

People who are pregnant or lactating should avoid GABA supplements since GABA has a direct effect on growth hormones, progesterone, and prolactin levels, which can impact the growth and development of a fetus or infant.19 Similarly, children should never take a GABA supplement, as it has the potential to interfere with their growth and development.

Professional athletes who are subjected to regular drug testing should avoid GABA supplementation, as well. While taking a GABA supplement isn’t exactly the same as using HGH in the traditional (banned) sense, the potential increase in hormone levels could be detected as such and result in disqualification.45

Regular alcohol users, people who use illegal depressive drugs like GHB, and those taking anti-epileptic or anxiolytic medication (such as Xanax or Lamictal) should stay away from GABA supplements to avoid compounding too much GABA in their system.

There’s a wide range of other options for improving symptoms of stress or anxiety, which we cover in detail under the “Alternatives to GABA” section later on.

Best overall

Thorne PharmaGABA uses a form of GABA (perhaps obviously) called PharmaGABA, the preferred type of synthetic GABA used by researchers across multiple studies on GABA supplementation. PharmaGABA was utilized in one of the few successful studies on GABA’s BBB permeability,42 44 and a 2017 case study even used Thorne’s PharmaGABA supplement specifically, noting that a 200-400mg dose could help relieve anxiety symptoms.24

PharmaGABA is also designated GRAS by the FDA as a food ingredient in doses up to 750mg, meaning Thorne’s doses (100mg or 250mg up to three times daily) are within a safe yet effective range.8

As a side note, if PharmaGABA interests you but you can’t swallow pills, competitor Quicksilver Scientific uses it in its GABA + L-Theanine liposomal liquid.

Thorne’s safety and testing procedures

Though it hasn't always been the case, Thorne currently maintains transparency surrounding its quality testing and safety processes. The company is NSF- and TGA-certified for cGMP compliance, which speaks volumes about the care it puts into manufacturing and consumer safety.

NSF certification entails random plant inspections and audits, as well as detailed product testing and retesting.30 Nutricost and Pure Encapsulations are also NSF-certified, but only Thorne is also certified by Australia’s TGA — a federal agency that’s similar to the FDA but much more strict in its regulation of supplements or “complementary medicines.”31 32

In terms of testing, Thorne participates in the NSF Contents Certified program, meaning its supplements are evaluated by an independent third party for the following:

• Label content verification (to ensure that what’s on the label is what consumers will get)
• Contaminants (microbials, heavy metals, pesticides, herbicides, etc.)
• Protein and caffeine verification, as applicable
• Disintegration testing (to make sure the supplements break down properly)

Maintaining compliance for NSF cGMP certification and the Contents Certified program are continuous processes, so product testing and facility audits happen frequently.

Additionally, Thorne has partnerships with multiple renowned research groups, including (but not limited to) Johns Hopkins University, Cleveland Clinic, Mayo Clinic, Mount Sinai, and the National Institutes of Health. This means that some of Thorne’s supplements have been:

• Used during independent research conducted by these organizations
• Evaluated for efficacy or safety by one or more of the organizations

Due to these partnerships, you can actually purchase some of Thorne’s supplements from these groups. For example, the Mayo Clinic offers a collection of around 150 Thorne supplements in its official online store.

Thorne PharmaGABA pricing, shipping, and satisfaction guarantee

You can get Thorne PharmaGABA in two doses — 100mg or 250mg per capsule. Every bottle comes with 60 one-capsule servings, but Thorne’s website notes that you can take up to three capsules daily. Taking the max dose of three capsules would reduce 60 servings to just 20, which could be rather costly over time — especially if you opt for the 250mg dose. Here’s how the pricing breaks down:

• Thorne PharmaGABA-100: $29 ($26.10 on second order with subscription)
• Thorne PharmaGABA-250: $53 ($47.70 on second order with subscription)

Even with the 10% subscription discount, Thorne’s 250mg PharmaGABA is the most expensive option out of our top picks. The 100mg option is up there, too. If you’d rather spend less capital up front when trying GABA for the first time, you may prefer NOW’s GABA supplement (about $14 for a 100-serving bottle) or Source Naturals’ GABA lozenges (an average of around $19 for a 120-count bottle).

Speaking of Thorne’s subscription program, it’s a bit different in that discounts don’t kick in until your second shipment. This policy was likely implemented to prevent people from subscribing and immediately canceling just to get the discounted price for a one-time purchase. Thorne’s discount starts at 10% off for subscriptions of one or two items and jumps up to 20% off if you subscribe to recurring deliveries of three or more products.

All Thorne orders to the contiguous U.S. get free shipping, but residents of Alaska and Hawaii will have to pay $30+ in shipping costs for orders under $300.

The company has a 60-day satisfaction guarantee that applies to purchases directly from Thorne or any of its authorized resellers. If you’re not satisfied with your Thorne product for any reason, you can request either a refund or store credit from customer service. Nutricost’s guarantee is the same length (60 days), while Quicksilver Scientific has a shorter, 45-day guarantee.

Best budget pick

NOW’s GABA capsules are a great option if you’re looking for a cost-effective way to get a high (500mg) dose of supplemental GABA, along with 2mg of vitamin B6 to help your body create more GABA on its own.46 Apart from vitamin B6, NOW GABA capsules also have three filler ingredients: rice flour, silicon dioxide, and stearic acid. They aren't bad for you — all things considered, they’re relatively minor additives meant to keep the supplement stable.

Unlike Thorne and Quicksilver Scientific, which specify using PharmaGABA derived from the fermentation of Lactobacillus hilgardii bacteria, NOW doesn’t disclose its GABA source. This is more of a disappointment than it is inherently bad — in fact, it’s actually pretty common for a GABA supplement — but knowing more about where the ingredient comes from would help us research it.

As evident from a systematic review of its pharmaceutical properties, GABA can be derived from several sources — certain types of germinated brown rice, fermented soybeans and lentils, fermented skim cows’ milk, tomatoes, and more.44 These various sources have been studied for different potential benefits. For example, GABA from fermented lentils and fermented soybeans (among other sources) have demonstrated potential angiotensin-converting-enzyme (ACE) inhibitor activity (meaning they may be able to lower blood pressure).44 47 That being said, we hope NOW discloses the source of its GABA in the future so we can further investigate any studies behind it.

Sourcing aside, NOW’s facilities are cGMP certified — like our other top picks — and its in-house testing lab is ISO/IEC 17025 certified, meaning that it meets the requirements for “competence, impartiality, and consistent operation” to ensure the “accuracy and reliability” of any conducted testing. Also, NOW’s GABA capsules are free of GMOs and common allergens, and they are vegan-friendly, kosher, and halal.

NOW GABA capsules pricing

NOW’s 500mg GABA supplement comes in two sizes:

• 100 capsules for $13.99
• 200 capsules for $25.99

A serving is one 500mg capsule, and there’s no way to take a lower dose unless you crack open the capsule and split the powder yourself (which we don’t recommend — there are much easier ways to get a smaller dose of GABA). If you’re looking for an even larger dose, however, NOW also sells a 750mg GABA supplement, without the additional vitamin B6, for $19.99 (100-count) or $36.99 (200-count).

The 500mg GABA capsules are about an inch long, which is definitely on the larger side, so some users may find them to be difficult to swallow. Thorne’s PharmaGABA capsules are about the same size.

Shipping is free if you order at least $50 worth of product; otherwise, it’s $6.95. And while NOW GABA capsules are relatively inexpensive (the least expensive capsules you’ll find on our list), you won’t get any additional bulk or subscription discounts. NOW doesn’t offer any subscription programs at all, so you’ll have to remember to reorder when you’re running low.

Additionally, if you want a refund, you can only return unopened packages within 30 days of purchase. So you can’t try the supplement, decide you don’t like it, and get your money back. If you’re worried about the financial risk, then Thorne, Nutricost, and Quicksilver Scientific may be better options due to their money-back guarantees.

Best with additional ingredients

The Source Naturals Serene Science GABA Calm lozenge has a great range of well-researched ingredients that provide additional GABA to your body while giving it the building blocks it needs to support natural GABA production. L-tyrosine (25mg) can stimulate dopamine production,6 taurine (20mg) may boost GABA's calming effects,5 magnesium (5mg) can increase GABA synthesis,36 and glycine (50mg) works alongside GABA as another inhibitory neurotransmitter.4

GABA Calm comes in two flavors (orange and peppermint) and three sizes (30, 60, and 120 lozenges per bottle). Like most of our top GABA picks, it’s available in only one strength: 125mg of GABA. Its lozenge form and specific dosage make it difficult to titrate, particularly if you want to halve it or take a higher dose that isn’t divisible by 125. If you know you need a larger or smaller dose — or more flexibility — we recommend starting with a different GABA supplement.

Another issue is that Source Naturals doesn’t actually sell any of its GABA Calm supplements directly. You have to go through a third party — like Target, iHerb, Vitacost, or Amazon — to purchase them. This, unfortunately, introduces the risk of not knowing whether or not you’re getting an authentic product. And, frustratingly, not every reseller offers every size and flavor. Throughout our research, we found that Amazon and iHerb generally have the best prices and availability, though the former has a bigger risk of getting a fake product, so we recommend iHerb.54

Pricing

Source Naturals does have recommended prices listed on its website, and most retailers stay within $5 of these recommendations:

• 30 lozenges: $7.25
• 60 lozenges: $14.25
• 120 lozenges: $26.98

Shipping, returns, and any potential guarantees depend on the seller you use. Amazon, for instance, disallows returns for safety reasons, while iHerb gives you 30 days to initiate a refund or replacement.

Best for bulk purchases

Similar to our other recommendations, Nutricost's GABA powder is produced in a cGMP-compliant and FDA-registered facility. Yet it’s a unique option among our top picks in that it takes a page from common workout supplements and comes in a large tub with a portioning scoop. Of course, like those workout supplements, you'll have to mix the powder into some kind of liquid to take your 500mg dose of GABA.

A powdered supplement requires more time and effort to take, but it also gives you total flexibility over how much you take. Having a kitchen scale helps you measure your ideal amount and circumvent human error. Without a scale, it can be tricky to dose consistently. So, the trade-off for not having to buy additional product for over two years is that you may need a new piece of kitchen equipment.

Another potential inconvenience involves GABA’s shelf-life. According to the FDA’s GRAS document on PharmaGABA, the shelf life of GABA is only about two years after its manufacturing date.8 Depending on how frequently Nutricost manufactures its GABA powder, you may get a container with only a year-long shelf life (or less, or more). Because of this, Nutricost’s GABA powder may be best for households with two or more people taking the supplement.

Pricing

The biggest advantage of the Nutricost powder, and the reason it’s our choice for bulk purchases, is that a single tub contains 1,000 servings for only $28.95. The price has gone up $6 in recent years — it was $22.95 when we first reviewed it — which is a relatively large increase compared to other GABA supplements (Thorne and NOW only saw $1 increases in the same amount of time), but the increase only raises the price per serving by one cent, from $0.02 per serving to $0.03 per serving. It’s still a phenomenal value for what you’re getting. Considering that our other top picks cost at least five times more per serving (with Quicksilver Scientific being the priciest at $1.48 for each dose), Nutricost’s GABA powder is a great bulk deal if you don’t mind dealing with a powder.

Shipping is free on U.S. orders over $59. If your order falls below the $59 threshold, your shipping fee depends on where you’re ordering from. However, Nutricost has a flexible 60-day money-back guarantee, like Thorne, so you can get your money back (minus shipping costs) within a two-month timeframe, whether you’ve tried the product or not.

Strongest option

At 700mg, the Pure Encapsulations GABA capsules are the strongest of our top picks. The dose is only 50mg below what the FDA recommends as a safe daily amount.8 A short-term study from about 40 years ago gave human subjects up to 18g without any severe adverse effects, but going beyond the suggested 750mg is a risk we don’t recommend taking without explicit approval from your doctor.21 With that in mind, we don’t recommend starting out your GABA journey with Pure Encapsulations, but it could be a good option for more experienced users who know how GABA affects them.

Pure Encapsulations GABA capsules also include some vitamin C (listed as ascorbyl palmitate). It’s not listed in the Supplement Facts box on the label; rather, it’s hidden within the “other ingredients” after the components that make up the capsule itself. Since it’s literally the last item on the ingredients list and the company didn’t see fit to add it to the Supplement Facts box, it’s probably a very, very small amount of vitamin C. (Manufacturers are required to list ingredients from largest to smallest quantity).48

Because the proportion of vitamin C is likely pretty minuscule, it probably doesn’t have much of an effect on the supplement’s efficacy. However, in larger doses, vitamin C may enhance the inhibitory ability of GABA (and the excitatory effects of glutamate).49 50

Pricing

Pure Encapsulations’ GABA supplement is available in two bottle sizes:

• 60 capsules: $21.00
• 120 capsules: $36.00

You can also subscribe to autoship deliveries and save 10% on each shipment. Like most of our other picks, the prices have gone up for this supplement in recent years (it cost $18.80 and $32.75 last year). However, if you need a higher dose of GABA than what most companies offer, then Pure Encapsulations’ supplement is likely more cost-effective. For example, purchasing the 250mg PharmaGABA from Thorne and taking three per day (750mg total) would cost you $106 for a little over one month’s worth of servings. But a month of 700mg GABA from Pure Encapsulations (about 30 capsules, or half of a 60-capsule bottle) would only be $10.50 (or $8 if you purchase the 120-capsule variety).

Some authorized resellers of Pure Encapsulations, like PureFormulas (it sounds similar but isn’t owned by Pure Encapsulations), have highly customizable subscription intervals; you can set the shipment frequency to however often you desire, and shipping is free on all purchases. We recommend this third-party seller over buying direct due to the convenient flexibility (both have the same subscription discount of 10% and offer free shipping).

Easiest to take

Quicksilver Scientific's GABA + L-Theanine liquid has one of the more interesting delivery mechanisms on our list. To take one serving, you'll need to put 2-4 pumps directly into your mouth, under your tongue, and let it absorb for 30-90 seconds (four pumps will get you the full 250mg GABA dose). While it may be awkward at first, it can also be one of the more convenient methods of taking GABA; there’s no need to mix a powder or have a drink nearby to wash down a pill.

A serving of Quicksilver Scientific gives you 100mg of L-theanine in addition to the GABA. L-theanine is the amino acid in green tea that promotes relaxation and counteracts the jittery feelings you might get with caffeine. Thus, it has not one but two amino acids to help you calm your natural stress response.51

This GABA liquid employs liposomal delivery. Liposomes, which are “microscopic and spherical manmade cells,” are generally used for supplements that your body has difficulty absorbing through the GI tract, like vitamin C.55 They can protect the supplement's contents until they’re ready to be dissolved, reduce the chance of toxicity, and help them pass through the thin membranes in your mouth (which is also why taking some supplements sublingually can help.)56

While it’s a great idea to do this for GABA, it’s unclear if it actually improves absorption in this case. Liposomal delivery may work better for supplements requiring GI absorption, but it’s hard to say just how much more effective liposomal delivery is than a capsule or powder in crossing the BBB. There isn’t a whole lot of research on liposomal GABA, either. One of the only studies on the topic involves rats being given a brain injection of GABA, which isn’t very comparable to sublingual liposomal GABA in a human.52

Pricing

The biggest con with Quicksilver Scientific’s GABA is the cost; a 25-serving bottle costs $37.00, and a 10% subscription discount only reduces the price to $33.30 ($1.48 and $1.33 per serving, respectively). The next most expensive per-serving cost among our top picks is $0.88 with Thorne’s 250mg option — a $0.60 difference relative to Quicksilver Scientific. That might not sound like much, but it can definitely add up over time. If you saved $0.60 on each of Quicksilver Scientific’s 25 servings, you’d have an extra $15.

Another price-related drawback is that Quicksilver Scientific only offers free shipping if you spend $99 or more. The threshold was $50 last year, and a hike of $49 feels a bit outrageous to us, considering the supplement's already high price. On a positive note, though, the company does offer a 45-day satisfaction guarantee, up from 30 days last year. While still not as long as the policies from Thorne and Nutricost, we do appreciate the extension.

As good as GABA might seem for combating anxiety, stress, and insomnia, it isn’t going to work for everyone. Your body — and especially your brain chemistry — is unique, and what’s effective for someone else may not be best for you.

If you find that GABA isn’t working for you, or if you can’t take GABA due to pregnancy or a contraindication, here are a few options that might suit you better: