Autoimmune Thyroid Disease and Anxiety


Note: Originally published in February 2016, this article has been revised and updated for accuracy and thoroughness.

The other day, I was speaking to a wonderful woman who was struggling with anxiety. She had already seen some major improvements with her Hashimoto’s through the use of thyroid medications as well as eating a Paleo diet, yet she was still struggling with anxiety.

I know anxiety was a huge struggle for me as well as for many of my clients with thyroid conditions.

Not many people are aware, but anxiety is a very common thyroid symptom. A study in 2004 found that there is an association between the presence of a mood or anxiety disorder and the presence of anti-TPO antibodies.

It also noted that a slight reduction in thyroid hormone secretion (such as that found in subclinical hypothyroidism) may affect mood as well! This means the anxiety you are feeling could be related to your thyroid! Trudy Scott, a nutritionist who specializes in anxiety reports that up to 50% of her clients with anxiety have Hashimoto’s!

It’s not uncommon for patients to be dismissed as having stress or anxiety and to be given anti-anxiety medications without thyroid function ever being considered.

My Personal Anxiety Journey

Anxiety was one of the most challenging and disempowering symptoms I experienced when I was first diagnosed with Hashimoto’s. It changed my life dramatically and made me a shell of my former self.

I was always the outspoken, level-headed and calm person, but sometime in 2005, something called “new-onset anxiety” was a shock to my world.

I was scared.

I couldn’t deal with life. I was in a constant state of overwhelm. I doubted myself.

A lifelong social butterfly, I suddenly found myself feeling socially awkward and uncomfortable in groups of strangers (and even friends).

I resisted sharing my thoughts and opinions with colleagues and those in my personal life because I feared I would be judged and ridiculed.

I was always on edge, waiting for something bad to happen. I would almost jump out of my seat when people came into my office at work!

I was constantly worried about everything and was crippled by my anxiety almost daily. I was a newlywed when this started happening.

My new husband would go out jogging, and if he was still out after thirty minutes had passed, I would be crying on the floor, worried that he got hit by a car (or worse, ran off with another woman 🙂 ). I knew that I was completely irrational (we just celebrated our 10 year anniversary even though my hubby goes running most days). But the truth was, I was not able to control my thoughts and emotions.

I thought I might have had a new-onset anxiety disorder, so I saw a doctor who prescribed anxiety medications for me. At times, I felt like I couldn’t deal with anything without them.

Of course, these medications did not get to the root cause – they were just a band-aid – I found a way to address my anxiety through the many things that I did to address the health of my thyroid gland.

Do You Struggle With Anxiety?

Let me ask you…

  • On a regular or frequent basis, do you have anxiety or feel stressed and overwhelmed?
  • Do you get panic attacks? Or feel awkward or uncomfortable in social situations?
  • Do you have obsessive thoughts or behaviors?
  • Do you have a busy mind that won’t switch off, or negative self-talk and problems sleeping?
  • What about emotional or stress eating?

These anxiety symptoms are very common in people with thyroid disorders.

I know how awful anxiety and overwhelm can feel, so I’m excited to share that there IS a way out and you don’t have to feel this way forever.

The Conventional Approach to Anxiety

The conventional approach to anxiety focuses on using medications, including SSRIs (Prozac, Zoloft, Lexapro, etc.) and anxiolytic medications like the benzodiazepines (Ativan, Xanax, etc.)

There are many well-documented side effects of antidepressants and benzodiazepines, ranging from the rare but serious; suicidal ideation/action, homicidal ideation/action and even death to the very common; more brain fog, weight gain, sexual dysfunction and feeling disconnected from reality. And as you may have guessed, I don’t think that anxiety is a “Prozac-deficiency” or a “benzodiazepine deficiency.”

As a pharmacist who once specialized in psychiatry, I believe that most medications have their time and place. If medications can help someone feel better and get through a difficult time in their lives while the benefits outweigh the risks, then fabulous! But after my own personal journey with taking back my health and training in functional medicine, I’m really interested in helping people with anxiety by addressing root causes and looking for solutions that are based in lifestyle and are free of side effects!

Some, ahem, Unconventional Approaches to Anxiety

People do various things in an attempt to control their feelings of anxiety, fear, irritability, obsessive thoughts, frustration, or “impending doom,” as panic attacks have been described by some.

Some people turn to alcohol to self-medicate their anxiety. This is especially common in the situation of social anxiety. Alcohol can lower our natural levels of inhibition and make us less self-conscious and more bubbly. Unfortunately, this can lead to a dependence on alcohol, and doesn’t resolve the underlying root cause of why we are anxious in the first place.

Some of my readers have sworn by using cannabis for anxiety. While I appreciate and value the role of medical marijuana for various conditions, marijuana in itself is not usually an ideal choice for people with Hashimoto’s. While various strains with various properties of marijuana exist, in many cases, marijuana may also have undesirable side effects, such as forgetfulness, paranoia, being tired, and getting “the munchies.” Not exactly an ideal treatment for a person with brain fog, anxiety, fatigue and weight struggles!

Additionally, in my experience, long-term use marijuana can produce or exacerbate apathy, which has been coined as “amotivational syndrome.” I know for many of my clients with Hashimoto’s, the lack of motivation and apathy are very stressful symptoms.

I’ll never forget a client I saw in my early days as a consultant pharmacist. He was a young man who was smart, handsome and well loved, yet he had a difficult time becoming motivated. He initially came in for a consultation with his father to ask me about whether any of the psychotropic medications he was taking could contribute to the lack of motivation.

While medication side effects are always a possibility, the big elephant in the room was that he used marijuana every day, even starting his mornings with smoking. His father was surprised that the marijuana could have this effect on his son, as he had used it himself for stress, yet it did not impact his own motivation. We have to remember that every person’s chemistry and situation is different, and we don’t always respond the same way to the same substances!

And of course, another obvious reason why I don’t recommend cannabis for most people with Hashimoto’s is because it’s still illegal in most places!

The True Root Causes of Anxiety

On a grand scale, anxiety, just like most other symptoms we experience, is a sign that something is out of balance within our bodies or our lives.

Anxiety could result from blood sugar imbalance, thyroid hormone abnormalities, an autoimmune attack on the thyroid gland, nutrient deficiencies, food sensitivities and even other root causes, such as toxins and chronic infections.

Another common root cause of anxiety really goes into our stress response. If we’ve had traumatic experiences in our lives, this may predispose us to be more anxious and hypervigilant… If we have current situations that are outside of our coping strategies, we may also feel more anxious.

In people with anxiety, our chemical messengers-neurotransmitters and hormones are often going to be out of balance, specifically GABA, Cortisol and Serotonin are thought to play important roles.

My approach to anxiety is to address the underlying root causes, as well as use targeted approaches to rebalance the brain and body patterns that are safe and effective.

The Root Cause Approach to Anxiety

While the root causes may vary from person to person, I wanted to share some strategies you can start right away. You don’t have to be anxious- there are some pretty simple hacks that can work wonders!

I love starting with things you can do on your own that don’t require fancy detective work. These things include using food and nutrients to balance your mood!

Addressing blood sugar imbalances, food reactions, deficiencies and the stress response are a part of fundamental strategies that will help 60-80% of people overcome anxiety!! In some cases, you just need to do one of the below. For best results, I recommend making all of them a part of your day to day life!

The Fundamental Anxiety Reduction Strategies.

1. Balance Your Blood Sugar

One of the most important things you can do to reduce your anxiety is to address your blood sugar. Blood sugar swings can put us on an emotional rollercoaster. After consuming carbohydrate-rich foods, some people find their blood sugar goes up too high, too quickly.

This leads to a rapid, sometimes excessive release of insulin. These insulin surges can cause low blood sugar, which can cause unpleasant symptoms such as anxiety, nervousness, lightheadedness, fatigue and irritability (or feeling “hangry” as I like to call it)- so a big recommendation I have is to balance your blood sugar.

You can do this by reducing your intake of carbohydrates, and increasing your protein and fat intake. A low-carb or ketogenic diet (a low-carb diet where the body breaks down fats for fuel instead of relying on carbohydrates) could be beneficial for some.

Often times, breakfast can make or break your whole day. I recommend starting the day off right by having a breakfast that is filled with good fats (for example, avocado or coconut milk), as well as a good source of protein, while limiting your intake of sugars, even from fruit.

Some breakfast options include eggs with avocados, burger patties and protein and fat-based smoothies. My Root Cause Green Smoothie is an option I created specifically with the intention of keeping blood sugar balanced. I’ve developed a specific protein powder that is also autoimmune Paleo friendly, my Al Paleo Protein.

Another important note- people often ask about intermittent fasting and skipping breakfast. While this can be a fantastic way for some people to feel better, lose weight and reset their bodies, it can be an absolute mood rollercoaster for people with imbalanced blood sugar and adrenal issues.

As most people with Hashimoto’s and anxiety, have blood sugar imbalances and adrenal issues, I recommend eating a good breakfast and abstaining from intermittent fasting. The only exception would be if you are already keto-adapted (i.e. you’ve been eating a ketogenic diet for a while and your body burns fat instead of sugar for fuel). If your body is burning ketones instead of sugar, you are less likely to experience the blood sugar swings.

I also recommend eating frequent protein and fat containing meals and snacks to balance your blood sugar throughout the day. Adding fat containing substances like coconut oil into your beverages throughout the day can also make you feel more calm and collected. (Just make sure that the beverages are not too hot when you decided to sip on them, the hot coconut oil could burn your tongue and mouth #thingsIlearnedthehardway)

Finally, amino acid supplements can help with stabilizing your blood sugar, and will thus lessen your anxiety. I recommend Amino NR to be taken three times per day.
Others have also benefited from using L-Glutamine for low blood sugar (starting with 500mg per day).

Balancing my blood sugar made a big difference for me, helping with my anxiety levels and reducing my thyroid antibodies! I have written an article that goes into greater depth about balancing blood sugar,and I also developed blood sugar rules I personally follow to stay balanced.

blood sugar balancing rules

2. Reduce Your Caffeine Intake

If you’re currently drinking coffee, soda, green tea or black tea, removing or reducing your intake of caffeine can be really helpful. Caffeine is a stimulant that can make us feel edgy and can lead to heart palpitations and increased feelings of anxiety. I know that personally, I have a limit of how much caffeine I can have in a day until I become anxious.

For some people, who are slow metabolizers of caffeine and may not clear it effectively out of the body, they may not be able to have any- not in coffee, sodas, teas and even chocolate! (Carob is a tasty, caffeine-free, autoimmune Paleo friendly chocolate substitute, BTW).

Others, who are fast metabolizers (clear caffeine faster from their body) may be able to tolerate more daily caffeine without an impact on their anxiety levels.

Regardless of your genes and metabolism of caffeine, generally, the weaker your adrenals and more of-balance your blood sugar, the more likely you are to experience anxiety from caffeine. This is because caffeine forces more glucose to be produced by the liver, sending us on a blood sugar roller coaster…

I happen to be a fast metabolizer, so I can tolerate some caffeine, but I was really overdoing it around my initial Hashimoto’s diagnosis; I used to drink caffeinated beverages 6-8 times per day, including at bedtime! I wasn’t aware how much caffeine was impacting me until one of my doctors suggested I cut down. One of my big complaints was that my sleep was often too light. The slightest noises would wake me up. I was shocked that cutting down on caffeine resolved this issue completely.

Other clients have had anxiety, headaches, palpitations, insomnia and frequent urination resolve with reduced caffeine.

Reducing your caffeine intake and drinking hot lemon water or herbal tea instead can help reduce anxiety. Some people may also need to eliminate chocolate. (I know, bummer, but I’d take being happy and calm over having a chocolate bar! :-))

If you’re thinking about reducing your caffeine intake, I do recommend doing it gradually overtime, instead of just stopping it cold-turkey, as going cold turkey on caffeine can cause withdrawal symptoms such as headaches, fatigue and even vomiting. #thingsIlearnedthehardway

Reducing intake by about 50% every 1-3 days is a good pace for most people.

3. Food Reactions

The most common food reactions responsible for anxiety symptoms are due to gluten, dairy, soy, grains (especially corn), sugar, caffeine (as discussed above) and surprisingly to some- nuts.

Doing targeted food sensitivity testing, or simply a trial of eliminating the suspect foods for 3 weeks or so can help you uncover your food triggers.

For me personally, I couldn’t figure out why I had menstrual breakouts and PMS symptoms some months and not others. Eventually, after some trial and error, I realized that nuts were making me nuts! I am not 100% sure what it is about the nuts that causes this reaction, but I have seen this reaction in numerous clients, especially with almonds. For this reason, I do avoid nuts to this day.

You can read more about food sensitivities [HERE] and food myths [HERE], for more information about testing and doing the elimination diet.

4. Balance Your Thyroid with Selenium

Having an excess amount of thyroid hormone can make us extremely anxious, irritable and on edge. This is one symptom that is commonly attributed to Graves’ disease but can also happen in Hashimoto’s.

In the early stages of Hashimoto’s, the thyroid is under attack by the immune system. Thyroid antibodies are a marker that lets us know that the immune system is destroying thyroid tissue.

When thyroid cells are broken down, they release thyroid hormones into the bloodstream. This causes thyroid hormone surges or a transient hyperthyroidism known as thyrotoxicosis or Hashitoxicosis, as well as mood alterations, followed by an onset of hypothyroidism.

While many deficiencies have been implicated in both Hashimoto’s and anxiety, the most common ones I see in both conditions are deficiencies in selenium, magnesium, and probiotics. Addressing these deficiencies can help both the thyroid and anxiety symptoms!

One of the things that can be incredibly helpful with rapidly reducing the attack on the thyroid gland is selenium. One study found that over the course of 3 months, thyroid antibodies, which indicated the aggressiveness of the attack, can reduce by 50%!

Selenium, which has been shown to be helpful with reducing the autoimmune attack on the thyroid as well as reducing hair loss, can work wonders in reducing anxiety in people with thyroid antibodies. Many of my clients report feeling brand new with a small daily dose of Selenium. I recommend Selenium Methionine at 200-400 mcg per day.

Additionally, if your TSH is elevated or suppressed, you may need to initiate or adjust thyroid hormones. The ideal TSH for most people is between 0.5-2 IU/L and levels too high and too low indicate an imbalance of thyroid hormone levels and have been associated with various symptoms, including anxiety. You may want to read my article on Understanding Your Thyroid Labs and Taking Thyroid Medications for more information.

5. Consider Beneficial Bacteria

Studies have found that the gut is in charge of producing neurotransmitters, including serotonin, one of the neurotransmitter that is thought to be lacking in anxiety and depression.
Healthy gut bacteria assist with the production of serotonin, so taking probiotics or eating fermented foods may be helpful. You can read more about this in my post about probiotics. One caveat: If you have obsessive thoughts, you will want to stay away from probiotics that contain Streptococcus probiotic strains, as they can theoretically increase obsessive-compulsive symptoms.

An overgrowth of Streptococcus (Strep) bacteria has been implicated in obsessive-compulsive disorder. Though I haven’t seen anyone worsening with Streptococcus containing probiotics yet, it’s always better to be safe than sorry. As a side note, if you have obsessive-compulsive symptoms, you may want to test your gut for an overgrowth of Streptococcus. The herb berberine can help with rebalancing this bacteria and once the bacteria is gone, often times, your obsessive symptoms leave with it! {if you’d like me to write an article about overcoming obsessive-compulsive, let me know in the comments}.

6. Mind Your Magnesium

magnesium supplement throughout the day or at bedtime can be beneficial as well for anxiety. Magnesium is especially helpful if you have insomnia or a racing mind when you’re trying to fall asleep. Some signs and symptoms of magnesium deficiency include headaches, insomnia, constipation, anxiety and menstrual cramps.

I recommend that my clients take the citrate version if they tend to be constipated (magnesium citrate has stool softening effects), and the glycinate version if they tend to have normal bowel movements or diarrhea. Keep in mind that for some people, magnesium glycinate can worsen anxiety symptoms. If you notice that your anxiety increases after taking magnesium glycinate, try switching to magnesium citrate. Side bonus: magnesium can also prevent headaches, body aches, and menstrual cramps!

7. Manage Your Stress Response

One of the ways to become less anxious is to increase our resilience to stress. We can increase your resilience by supporting the health of our adrenal glands, two tiny glands that produce our stress hormones including cortisol.

One sign that your adrenals need support is if you are easily overwhelmed, annoyed, anxious or irritated by others. For me, the ultimate clue that my adrenals are over-stressed and need more support is if I find EVERYONE annoying and/or demanding… If there’s a day when my mom calls to say hello and I’m annoyed and my sweet little dog even gets on my nerves for being a dog, I know that my adrenals need some TLC!

For me, my adrenals usually get stressed after a period of not getting enough sleep. The fastest way to crash adrenals is with sleep deprivation- the fastest way to recover them is to get extra rest! So… get some rest, take a nap, sleep in, or go to bed early!

If extra sleep doesn’t solve the problem, isn’t possible or you’ve had a long term case of anxiety, you may want to consider another one of my favorite ways to support the adrenals… adaptogenic herbs!

An adaptogen, by definition, is a substance that can increase the body’s resilience to different types of stress, including physical and emotional stress. To be considered an adaptogen, an herb must:

  1. Be non toxic to the patient at normal doses.
  2. Help the entire body cope with stress.
  3. Help the body to return to normal regardless of how stress is currently affecting the person’s functioning.

Adaptogens both tone down overactive systems and boost underactive systems in the body, and are thought to help normalize the hypothalamic-pituitary-adrenal (HPA) axis. Examples of adaptogenic herbs that may increase the body’s ability to resist stress include: ashwagandha, astragalus, reishi mushroom, dang shen, eleuthero, ginseng, jiaogulan, licorice, maca, schisandra, spikenard, and suma. These herbs have been helpful in relieving adrenal dysfunction when used in combination with vitamins and minerals.

Clients and readers who start taking adrenal adaptogens often report that the people in their lives all of a sudden become less annoying, demanding and more pleasant 🙂 It’s amazing what perception can do for our stress and anxiety.

I formulated Rootcology Adrenal Support to combine these types of herbs and nutrients which are known for rejuvenating the adrenals, into one supplement. Another high-quality option is the Daily Stress Formula by Pure Encapsulations.

Here are some additional strategies, I recommend to reduce stress:

  1. Do your best to eliminate, simplify, delegate, automate.
  2. Be more resilient by being more flexible. Bruce Lee once said: “Notice that the stiffest tree is most easily cracked, while the bamboo or willow survives by bending with the wind.”
  3. Do the things that you like.
  4. Orderliness and predictability are your friends. Plan your life that way when you can. Catch up on bills, checkbooks, and your long to-do lists. Keep your space neat and clean. Schedule times to clean the house and catch up on life, not just big events. Make sure you schedule downtime as well.
  5. Avoid burning the candle at both ends.
  6. Massage, acupuncture, meditation or tai chi may help get you relaxed.
  7. Avoid multitasking. Do one thing at a time and keep your full attention on it before you move on to the next task. Take a small break in between tasks.
  8. Start a journal, make your own list, be mindful of what makes you feel better and what makes you feel worse.

8. Mindfulness

Mindfulness is a term used to describe being conscious and aware of the present moment. This is probably the most important suggestion- mindfulness will allow you to take deliberate control of your thoughts and emotions and is a lifelong strategy that will help you in any challenging situation.

I usually spend time with each of my clients who struggle with anxiety on specific exercises and methods to help them get centered and in control when anxiety strikes. These strategies also work to prevent anxiety. For example, you can try yoga, deep breathing, adult coloring books, meditation or massage.

I really like the Muse headband for developing a meditation habit!

Whatever you can do to shut down your worried brain for even just a few minutes a day will help you in the long term.


If you have a resistant case of anxiety, or are going through a particularly anxious time, it may be time for you to consider some more advanced strategies!

9. Neurotransmitters

GABA is our naturally occurring neurotransmitter that is known to produce calmness, reduce tension and reduce anxiety.

Benzodiazepine and anti-anxiety drugs target this pathway and are very effective at reducing anxiety, but unfortunately, they are habit forming and produce side effects! This is because like many drugs, they have a high affinity for the receptors in our bodies. In very simple terms, they crank up the receptors to overdrive, instead of balancing them like naturally occurring GABA does.

Luckily, GABA is available as a supplement.

When I first heard about using GABA orally as a supplement, I didn’t think it would be helpful because the molecule size is too large to cross the blood-brain barrier, but alas, neurotransmitters are also produced in our gut, and thanks to the intricate feedback system within our body, taking GABA orally still sends signals to our brain and body to relax.

According to Trudy Scott, chewable forms tend to work better, as they are more readily absorbed through our mucous membranes.

People who take GABA report more muscle relaxation, less anxiety, irritability, feeling lighter, and being able to laugh more, as opposed to “freaking out,” while remaining alert and without the drugged feeling you would get from benzos or alcohol.

Some GABA supplements:

Phenibut is a substance that impacts our GABA levels which have been associated with anxiety. While some biohackers have found this supplement effective for anxiety, unfortunately it is also habit forming, so I have a hard time recommending it. 🙁 (Phenibut is available as a supplement in some countries, and regulated as a drug or controlled substance in others).

10. Reprocessing Past Traumas

If your anxiety results from events that occurred in your past, utilizing therapy may be the path to reducing or eliminating your anxiety. In many times, this will also help your thyroid.

Trauma and autoimmune disease go hand in hand as well. Traumatic events that aren’t properly processed and continue to haunt us are in my opinion no different than walking around full of toxins in our bodies. They are bound to make us sick eventually! Extensive research I’ve cited in Hashimoto’s Protocol, has established a causal link between trauma, and autoimmune disease.

While there is certainly a physical side of Hashimoto’s, our whole body is a system with intricate feedback loops, and in that system we can’t ignore our mind and emotions.

It took me many years to realize this, but my anxiety over losing my husband while he was jogging, as ridiculous as it sounds, was not just stemming from the attack on my thyroid, but from past trauma as well.

Before I met my husband, I lost a loved one to a sudden, unexpected death. My Hashimoto’s symptoms, as did my anxiety, worsened after this loss. I know I’m not alone in this, 17.6% of people with Hashimoto’s who took my 2015 survey reported that they had lost a loved one before their Hashimoto’s diagnosis- other clients reported losing loved ones as significant exacerbating factors.

While I sought grief therapy for this loss, this sudden tragedy continued to replay inside of my nervous system and my unconscious. Many years after, I frequently had dreams, nightmares and flashbacks related to this loss. It wasn’t until I did a targeted therapy known as EMDR that I was able to overcome the trauma associated with losing the loved one.

EMDR or Eye Movement Desensitization and Reprocessing is a method used by psychotherapists to help people eliminate the lasting effect of traumatic events. This method can help people overcome traumatic events when other methods fail.

Francine Shapiro, PhD, who noticed that certain eye movements reduced the intensity of her disturbing thoughts and made her less anxious during a walk in nature, initially developed this method. She tested the method with trauma victims and published her findings in 1989, establishing it as an evidence-based level treatment for trauma and post-traumatic stress disorder. I highly recommend working with a therapist who specializes in EMDR if you have encountered traumatic events in your past- I assure you, you can get past them. If you’d like me to write an article about my experience with overcoming traumatic events and rebalancing my stress response, let me know in the comments!

Other Things to Consider

If your anxiety continues with all of the above interventions, you may also want to consider additional conditions such as pyroluria and copper toxicity, as both conditions can contribute to anxiety. I also have found Neurofeedback (I like the Neuroptimal unit), nutritional lithium and homeopathy (try Rescue Remedy) as helpful interventions. My new book Hashimoto’s Protocol includes additional advanced protocols, including a copper toxicity protocol that may help!

Book Recommendations

  1. Hashimoto’s Protocol
  2. Hashimoto’s the Root Cause
  3. The Antianxiety Food Solution: How the Foods You Eat Can Help You Calm Your Anxious Mind, Improve Your Mood and End Cravings – Trudy Scott
  4. Ease Your Anxiety – Joan Rosenberg
  5. How To Stop Worrying and Start Living – Dale Carnegie
  6. Getting Past Your Past -Francine Shapiro

Here’s the takeaway: you are NOT going crazy! Anxiety, as well as other mood disorders such as depression, can be misdiagnosed and have thyroid imbalances as an underlying root cause. And of course, the root cause of your anxiety may be different from another person’s. (Please note: the suggestions in this article are not meant to replace your physician’s advice; please consult with your doctor before adjusting any medication prescriptions.) But with the right interventions, you can improve your anxiety and get back to living out your dreams and the life you imagined without fears and limitations.

I hope this helps and I wish you all the best on your health journey!

In the meantime, here’s an image you can print out to help you remember some of the best ways to help your anxiety:


1. Carta M, Loviselli A, Hardoy M et al. The link between thyroid  autoimmunity (antithyroid peroxidase autoantibodies) with anxiety and mood disorders in the community: A field of interest for public health in the future. BMC Psychiatry. 2004;4(1). doi:10.1186/1471-244x-4-25.

2. Abdou A, Higashiguchi S, Horie K, Kim M, Hatta H, Yokogoshi H. Relaxation and immunity enhancement effects of gamma-aminobutyric acid (GABA) administration in humans. Biofactors. 2006;26(3):201-208. doi:10.1002/biof.5520260305