Amino Acids

You may have heard the term amino acids before, and thought it was just another boring biology term or acid that you used in chemistry class. In reality, amino acids are the actual building blocks of life. And no, we do not mean the building blocks like the ones you had in your toy box growing up.

These building blocks throughout your body regularly form chains that make up proteins in your body. Protein is crucial to keeping you healthy and energized, so it’s pretty easy to understand why amino acids are so important.

While you can lump all of these substances into an ‘amine’ group, there are many variations of these amino acids that all serve different purposes and functions within the body – a whopping 20 of them for proteins, to be precise.

What Are Amino Acids?

Protein plays a central role in nearly all biological processes, and amino acids[1] are the building blocks of protein. About 20% of the human body is made up of protein.

A large proportion of our tissue, muscles, and cells are made up of amino acids, indicating they carry out numerous critical bodily functions, such as giving cells their structure. Amino acids also play a vital role in the transport and the storage of nutrients. They influence the function of organs, tendons, glands, and arteries. They are essential for repairing tissue and healing wounds, especially in the bones, hair, muscles, and skin, as well as for the elimination of all sorts of waste deposits generated in connection with the metabolism.

According to Meirion Jones, a renowned BBC journalist, antithetical to years ago, many doctors and medical professionals have now reinforced the idea that the proper amount of amino acids (obtained either from foods or supplementation) can have many beneficial effects.

Robert Erdmann and Meirion Jones explain in their book “The Amino Revolution” the changes in medical opinion in the following way: “Unfortunately, in the real world, countless factors are working to prevent our bodies from receiving a full and balanced supply of these all-important substances. Among these factors are the pollution caused by burning fossil fuels, the hormones fed to cattle, the intensive use of fertilizers in agriculture, and even habits such as smoking and drinking, all of which can prevent our bodies from fully using what we eat. Worse still is the amount of nutrition that is lost from our food through processing before we get to eat it. By providing the body with optimal nutrition, amino acids help to replace what is lost and, in doing so, promote well-being and vitality.”[2]

Amino Acids Classification

As mentioned above, amino acids can be classified based on a variety of characteristics, including whether people can acquire them through diet. Therefore, scientists have identified three amino acid types:[3][4]

  • Essential
  • Conditionally essential
  • Nonessential

However, the classification as essential or nonessential does not reflect their importance, as all 20 amino acids are necessary for human health.

Essential Amino Acids

The body can not make essential amino acids which, as a result, they must be obtained from food or supplementation. The nine essential amino acids are:

  • Isoleucine
  • Histidine
  • Lysine
  • Leucine
  • Phenylalanine
  • Methionine
  • Tryptophan
  • Threonine
  • Valine

Conditionally Essential Amino Acids

These are typically not needed every day in your diet, but when you’re under stress, your body cannot manufacture these amino acids, and they must come from an outside source in your food. Conditional amino acids include:

  • Cysteine
  • Arginine
  • Tyrosine
  • Glutamine
  • Ornithine
  • Glycine
  • Serine
  • Proline

Non-Essential Amino Acids

Nonessential means that our bodies produce an amino acid, even if we do not get it from the food we eat. Nonessential amino acids include:

  • Asparagine
  • Alanine
  • Glutamic acid
  • Aspartic acid

How Amino Acids Benefit Your Health?

Amino acids can also be used as a source of energy by the body

The nine essential amino acids perform some important tasks in your body.


Phenylalanine is an essential amino acid, also acting as a building block for proteins, indicating that, although your body requires this amino acid for health, it is unable to produce it by itself. So, you have two ways to satisfy your demand in Phenylalanine – get it from food or get it from supplementation.

L-Phenylalanine is biologically converted into L-tyrosine, another one of the DNA-encoded amino acids. L-tyrosine in turn is converted into L-DOPA, which is further converted into dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline). Noradrenaline is responsible for promoting mental alertness and better short and long term memory, as well as for improving mood and the suppression of appetite.[5]

Since noradrenaline has an impact on mood, various forms of Phenylalanine are believed to treat such conditions as memory problems, lack of energy, confusion, depression, decreased alertness, and lack of appetite, all of which are considered to be the result of a Phenylalanine deficiency.

According to some research, Phenylalanine can help strengthen the effect of UVA radiation for people with vitiligo, treat chronic pain, and even Parkinson’s disease – there was a study on animals suggesting that Phenylalanine can improve walking disabilities, rigidity, speech difficulties, and depression caused by Parkinson’s disease.[6] Finally, Phenylalanine is considered to help treat depression, because it stimulates the production of brain chemicals like norepinephrine and dopamine.


Valine is an essential amino acid necessary for smooth nervous system and cognitive functioning.

This amino acid helps to prevent the breakdown of muscle because it supplies the muscles with extra glucose responsible for energy production during physical activity. This amino acid is also a precursor in the penicillin biosynthetic pathway and is known for inhibiting the transport of Tryptophan across the BBB (blood-brain barrier).

Valine offers various health benefits like reducing the intensity of the symptoms associated with nervousness and insomnia. Furthermore, it is also believed to help alleviate disorders of the muscles and to be an effective appetite suppressant. This amino acid also dramatically improves the regulation of the immune system, but probably the most significant benefits of Valine are experienced by athletes performing long-distance sports and bodybuilding, because this amino acid is essential for the muscle tissue recovery and muscle metabolism, while increasing exercise endurance.

Athletes and bodybuilders usually use Valine together with Isoleucine and Leucine to support muscle growth and to supply them with more energy. On top of that, Valine helps them recover tissues damaged during physical activity. Athletes commonly know that Valine is vital for the growth of muscle tissue and muscle metabolism as it assists in keeping the proper amount of nitrogen in the body.[7]


Threonine is an essential amino acid, i.e., it is indispensable for your health, but it has to be obtained from a diet or supplementation because your body cannot synthesize it. Threonine has many known benefits. Since Threonine is mainly found in the central nervous system, it can be beneficial in treating different types of depression.[8]

Threonine supports cardiovascular, central nervous, and immune systems, as well as liver function. Additionally, it helps in the synthesis of serine and glycine which, in turn, assist in the production of muscle tissue, elastin, and collagen. Also, Threonine speeds up the healing process after trauma or surgery and aids building strong bones and tooth enamel by boosting up the immune system.

Proper levels of Threonine can be found in most meats, eggs, and dairy. Vegans may obtain it from nuts, wheat germ, some vegetables, and beans, but in lower amounts.[9]


Tryptophan is recognized as the essential building block for numerous life-giving biomolecules: enzymes, structural proteins, melatonin, serotonin, and neurotransmitters. Serotonin plays a key role in a number of physiological functions like blood pressure, affective disorders, sleep, pain perception, and temperature. Tryptophan has been recognized as a potential mediator of central fatigue.

However, the importance of this amino acid doesn’t end there. Tryptophan helps to alleviate the symptoms of restless leg syndrome as well as treating menopausal depressive conditions. It also relieves stress and assists in controlling hyperactivity in children.[10]


Methionine is one of the essential amino acids necessary for your health, but it cannot be produced in the body, as a result, you need to provide it through your diet.

This sulfur-containing proteinogenic amino acid acts as an intermediate in the biosynthesis of different phospholipids. It is vital in single-carbon metabolism and helps the detoxification in the liver. If you lack a proper intake of sulfur, your body will be unable to produce and to utilize some antioxidant nutrients. Therefore, Methionine is a precious nutritional compound providing numerous benefits for your body.

Typically, most people do not need to supplement with Methionine when in good health. Generally, you can get some of this amino acid from food like dairy products, fish, and meat. Vegans or those who follow the low-protein diet[11] typically get enough Methionine from whole grains.

This amino acid is especially beneficial for people suffering from estrogen dominance, i.e., the volume of estrogen in the body is too high compared to that of progesterone. Women taking oral contraceptives can also find Methionine very helpful – acknowledging that estrogen is cleared through the liver, it is better to enhance the liver function to reduce the body’s estrogen load.[12][13]


Leucine is an essential amino acid that plays a major role in various metabolic functions and the synthesis of proteins. Leucine promotes growth and helps the recovery of muscle and bone tissues. Additionally, it helps in regulating the blood-sugar levels, as well as the production of the growth hormone.

Leucine is one of the most common ingredients in weight loss and muscle building supplements. Recent clinical research has revealed that Leucine acts in a unique way: unlike other amino acids, it helps in burning fat without “burning” the muscle by saving the muscle proteins and leaving them to assist in increasing and building muscle mass and gain.

Research has shown that people on a protein-rich diet, which includes the right amount of Leucine, lose more body fat while retaining more lean muscle mass. In other words, it is an excellent supplement for athletes or dieters who have to work out regularly in an attempt to build up muscles while keeping fat off the body.[14]


Isoleucine may be useful in many different ways. The amino acid plays a vital role in the regulation of blood sugar and energy levels, as well as hemoglobin synthesis.[15]

Similar to Leucine, Isoleucine is widely known as an amino acid capable of improving endurance and helping heal muscle tissue. That is why supplementation with Isoleucine may positively influence the increased muscle protein content in human bodies suffering from muscle protein loss.

It is particularly recommended for bodybuilders and professional athletes, as the primary function of Isoleucine in the body is assisting the body in recovering from strenuous physical activity and boosting energy levels.

Isoleucine also aids in preventing muscle wasting. This amino acid is known to hasten tissue repair after surgery or injury. Additionally, there is substantial evidence that this branched-chain amino acid family has anabolic effects on muscle protein synthesis.[16]

Finally, Isoleucine is converted to blood sugar in the liver, meaning it can help in maintaining healthy blood glucose levels.[17]


Lysine is widely recognized as an amino acid necessary as a building block for all proteins in your body and it plays an important role in calcium absorption, as well as in helping building muscle protein. Lysine also assists in recovering from traumas or surgery and helps your body produce antibodies, enzymes, and hormones.

It is vital for proper growth and is essential in the production of carnitine, which is a nutrient that lowers cholesterol levels and transforms fatty acids into energy. Lysine was also proved to support the central nervous system due to having antiseizure properties.[18]

Numerous studies revealed that Lysine assists the body in absorbing calcium and decreases the amount of calcium lost in urine. Since calcium is essential for bone health, you can surmise that Lysine may help prevent the bone loss caused by osteoporosis, but further research is needed to support this claim.[19]


Histidine is a special case. Because adults are generally able to produce it in adequate amounts but children may not, Histidine is usually referred to as a semi-essential amino acid.  Histidine is also known for being a precursor of histamine – a compound that is generally released by the immune system cells in an allergic reaction.

Histidine is needed to regulate and utilize essential trace elements like copper, iron, molybdenum, manganese, and zinc. This amino acid is also necessary for forming numerous metal-bearing compounds and enzymes, such as the antioxidant superoxide dismutase.

Metallothionein needs Histidine to be formed, so people without a Histidine-rich diet whose body is contaminated with heavy metals are subject to the body’s depletion of adequate stores of this amino acid, thus causing mineral-enzyme deficiencies and dysregulations. This body condition is best recognized by dysfunction of Histidine-dependent compounds, coupled with low blood plasma concentration of it.

What Foods Do I Need To Eat

As mentioned above Condionally Essential and Non-Essential Amino Acids come from our food first and foremost. So the next logical question would be, “What foods do I need to be eating to build up these amino acids?” A variety of foods[20] contain amino acids:

  • Eggs
  • Turkey
  • Chicken
  • Lamb
  • Cheese
  • Fish

Don’t worry if you’re a vegetarian or a vegan, as there are great options for you.

  • Seaweed
  • Pumpkin
  • Whole grain rice
  • Brown rice
  • Hemp seeds
  • Chia seeds
  • Sesame seeds
  • Watercress
  • Cabbage
  • Turnip greens
  • Soy
  • Peanuts
  • Sunflower seeds
  • Kidney beans
  • Spinach
  • Cranberries
  • Quinoa
  • Blueberries
  • Kiwi fruit
  • Avocados
  • Raisins
  • Dates
  • Apples
  • Olives
  • Bananas
  • Apricots
  • Oranges

If you’re someone who likes adding elegant touches to food, meal garnishes like mint, ginger, and garlic contain chemicals that produce amino acids. Feel like you’re not getting enough of these amino acids from the foods you’re eating? You may be surprised to know that there are brain supplements that will work with your body and provide you with much-needed amino acids.

Knowing what foods power all of the amino acid functions in your body is important, especially the ones located in your brain, the master controller over your entire body.


The amino acid approach to brain supplementation should be called the “common sense approach,” as you don’t need to be a doctor to understand why medical professionals claim amino acid supplementation works as our brains were intended to work, by rebuilding themselves – amino acids effectively “feed the brain.” Chances are you already know your brain’s neurotransmitters naturally demand essential amino acids (amino acids your body cannot manufacture) and conditional amino acids (amino acids your body cannot produce at certain times) every day from whole foods in your diet.

Our bare farming soils and sterile manufacturing processes result in a modern diet that often lacks these essential protein amino acids.

Without a proper supply of these essential amino acids in your diet, most people need to turn to supplementation of these essential amino acids which can commonly be found in whole food proteins.

The critical point here: amino acid supplements contribute in a natural way to your diet. It’s not a formulation of “forced ingredients” like you see in many of the multi-vitamin and herbal remedy approach supplements which we have reviewed here.

In short, an amino acid approach works to mimic or copy the exact formulation where these amino acids are found in actual whole-food proteins, which is essential.

This approach can allow the amino acids to get into your brain. To do that, your brain has to recognize the exact amino-acid formulation as it would naturally find itself in food. Only then will the amino-acids be allowed to pass through your sensitive BBB (blood-brain barrier) and start to nourish your brain.[21] This nucleus often includes other vitamins and minerals which can aid these amino acids in penetrating the BBB. Studies have proven that if you take large quantities of these amino acids by themselves, little to none actually can get through your BBB and into your brain.[22]

Once the amino acids have passed the BBB they can then rebuild the dopamine, norepinephrine, epinephrine, enkephalin, serotonin, GABA[23] and other crucial neurotransmitters responsible for making you feel calm, centered, and feeling positive every day.

Additionally, these amino acids can help to re-balance your serotonin and melatonin sleep hormone levels naturally instead of in an artificial manner. Unfortunately, the very common synthetic melatonin supplements artificially raise your melatonin levels and can often leave you feeling groggy the next day.

Most importantly, these amino acids can correctly nourish the hypothalamus, the master over your entire hormonal system, with the only amino acid that feeds it – phenylalanine.

Amino acids help you feel stronger, healthier[24] and they keep you in good working order. Eat plenty of amino-acid proteins and take an amino acid supplement to boost the effects.

As you know, there are many amino-acid supplements on the market and manufacturers that stand by there formulations, but choose wisely. Medical professionals know that these amino acids act as a management system in your brain and that they’re essential to life, especially when you know you aren’t getting the amounts you need currently in your diet.

Amino Acid Reviews

Looking for reviews of amino acid supplements? Browse our reviews below.


Reference Sources