The Complete Guide to Amino Acids

Complete Guide Amino Acids

You may have heard of amino acids before but maybe you weren’t really sure what they are? How do they work? Or what they can do for you?


If there is anything that is certain, you can’t escape amino acids. They are literally everywhere around you, inside and out. Every living thing that exists or will exist is made up of amino acids.

One of the things that are often said about amino acids is that they are the “building blocks of life”. This isn’t just a saying, they really are the puzzle pieces that make living things live.

This guide is meant to help people who don’t quite understand what amino acids are in an easy way without too much scientific jargon.

Our guide can be used by beginners who don’t know anything about amino acids. Or it can be used by students who just need to brush up before the big exam.

This guide is the complete resource on amino acids. If you want to know anything and everything about amino acids you will find it right here on this page. Countless hours have been spent crafting this guide for you. We really do hope you like it!

What are Amino Acids?

Most people have probably heard of “amino acids“, but not everyone knows exactly what they are. Amino acids may sound like a complicated scientific term but really they aren’t that hard to understand.

Amino acids are molecules that make up the protein in the body, and your body both uses amino acids to make proteins and breaks down proteins to make amino acids.

For instance, when you eat protein-rich food, your body breaks down that protein into individual amino acids. Those amino acids are then used to make proteins, like muscle tissue.

A great example of amino acids is to think of them as legos. One lego piece could be the equivalent of a single amino acid.

Now, if you combine many lego pieces together you will form some kind of structure. The same is true when many amino acids come together they will form a structure called protein.

What are the Different Kinds of Amino Acids?

There are two types of amino acids, essential and non-essential. Essential amino acids are not made by the body. They are called “essential” because you need to include them in your diet for optimal health.

Non-essential amino acids are amino acids that can be made in the body. They are called non-essential because you do not need to include them in your diet as long as you are consuming all of the essential amino acids.

How Many Amino Acids are There?

There are hundreds of amino acids that are known. In the future, there could be much more found or created in a lab. In total, there are only 20 basic amino acids that are in the standard genetic code. This means that the amino acids that make up living things only consist of these 20 amino acids.

With that said there are actually 22 proteinogenic amino acids. Proteinogenic means protein creating, the 2 additional amino acids can be incorporated by “standard translation mechanisms“.

The 21st and 22nd amino acids are selenocysteine and pyrrolysine. There are 54 known human proteins that contain selenocysteine. While pyrrolysine does not exist in humans.

The 20 basic amino acids in the human body are responsible for creating more than 50,000 proteins and over 15,000 enzymes. It’s amazing that just 20 amino acids can make up so many different combinations of proteins and enzymes that are vital for life as we know it.

Why are Amino Acids Important?

While essential amino acids tend to be fairly ubiquitous in dietary protein sources like meat, fish, dairy, eggs, and even some types of nuts and grains, non-essential amino acids can also be found in food sources, albeit to a lesser extent.

Making sure you get enough essential amino acids (and that your body can produce the non-essential ones) is vital to your health. Since amino acids are needed for virtually every metabolic process that the body has.

If your body didn’t have amino acids, then your body wouldn’t be able to make proteins. Every tissue in your body contains proteins, if there were no amino acids there would be no me or you.

Health Benefits of Amino Acids

Different amino acids have different health benefits. Some amino acids are especially important for the growth of nerve cells that form the myelin sheaths that cover nerves. A deficiency in this amino acid could lead to serious nervous system issues.

Other amino acids have been shown to assist with mood elevation and maintaining general motivation. While there may be others that assist with fat metabolism.

Since they are the building blocks of protein, nearly all amino acids help with muscle growth. This is why there are many different kinds of amino acid supplements that exist online and at health food stores.

The amino acids you see in workout supplements are likely to be branched-chain amino acids, or BCAAs, which make up human muscle tissue. However, many good-quality protein powders contain a complete amino acid profile.

Getting all the amino acids you need is very important for good overall health. Whether you get all your essential amino acids through a balanced diet with a lot of variety or opt to fill in some dietary gaps with supplements, getting enough of each is likely to improve your general sense of health and well-being.

Essential Amino Acids

Amino acids are the main building blocks of proteins that are present in every cell in the human body. There are as many as 50,000 different proteins. The largest of these is titin, a chain of more than 34,000 amino acids.

Ironically, there are only 20 different amino acids in proteins. Of these, eight are known as essential amino acids. Unlike the other 12, they cannot be synthesized by the body and must be ingested as part of the diet or in a nutritional supplement.

Some proteins have a fibrous structure. These proteins hold cells together, while another type, globular proteins, act as catalysts that speed up the thousands of biochemical reactions that take place in everybody every day.

Not all amino acids are incorporated into protein molecules. Some of them serve as neurotransmitters or hormones in their own right, while others are the precursors to other molecules.

All amino acids are organized the same way. Each one has a central carbon atom, which has the same three attachments. These are a hydrogen atom, (H-).

Other groups common to all 20 amino acids are the carboxyl group (-COOH) and an amino group (NH-2). What sets one amino acid apart from all the others is what is called its ‘R’ group.

The nature of the ‘R’ group has a profound effect on the chemical behavior of an amino acid. It can make it basic, acidic, hydrophobic or hydrophilic.

It may contain sulfur or it may bear an aromatic ring structure. Sulfur is significant because it is a component of nucleic acids, DNA and RNA.

Essential amino acid supplements are commercially available in powdered form, often incorporated into whey or other protein products, and as tablets or capsules.

They are particularly popular with athletes, bodybuilders, and anybody wishing to build up lean muscle. They are designed to minimize the tissue damage that sometimes occurs after intense strength training.


Histidine is one of the 20 amino acids required for our bodies to function properly. According to a 2013 study published in the Chemistry Central Journal, Histidine is the most active and versatile member of the amino acids and plays multiple roles in protein interactions.

Other studies suggest that our bodies do not naturally produce histidine. This amino acid must be obtained from dietary sources. High-protein sources are red meats, parmesan cheese, pork chops, poultry, fish, as well as soy, seeds and nuts, lentils, and other whole grains.

Histidine is essential because it works with the other amino acids to produce red and white blood cells by regulating antibody activity, contributing to metabolism, and serving to insulate nerves. Histidine also plays a part in producing histamine, which helps detect allergies and fight infections.

A diet high in histidine has many health benefits due to the protein component. For example, those who go to the gym regularly benefit from eating foods high in histidine because protein helps repair muscles broken down during heavy weight lifting.

Also, taking an L-histidine supplement with vitamins B3 and B6 can raise the levels of histamine, a hormone essential to heightened sexual pleasure and orgasms in women.

The proper balance of histidine in the body promotes sound mental and physical health, may help relieve symptoms of rheumatoid arthritis, and helps relieve stress and anxiety.


Isoleucine is an amino acid with a branched molecular chain. It is frequently referred to as a branched-chain amino acid, or BCAA, and sold in supplements alongside the two other BCAAs, leucine and valine.

These supplements are often sold in a 2:1:1 (leucine: isoleucine: valine) ratio, which mimics the natural concentrations of these amino acids in muscle tissue.

While you can find isoleucine in workout supplements, it is also found naturally in several types of meats, eggs, lentils, and cashews. Because the body has an optimal ratio of isoleucine and the other branched-chain amino acids, you will seldom see a supplement that contains isoleucine alone.

Isoleucine is very similar, in terms of both molecular structure and practical function, to the amino acid leucine. It is used medically for the healing of wounds. For fitness enthusiasts, it promotes muscular repair, which is vital for muscle hypertrophy.

However, while many people already know that isoleucine stimulates muscle growth alongside the other BCAAs, many don’t realize that it also has other major benefits for bodybuilders and those who just like to train.

Isoleucine can help to regulate your blood sugar, and it also can stimulate the release of human growth hormone. Blood sugar stabilization is good for overall health and can help your energy levels stay consistent. Human growth hormone can help to promote muscular growth as well.

While this amino acid helps with general health, it has some major benefits for the fitness enthusiast who wants to improve health and body composition. Even though it is not generally considered to be the strongest BCAA of the three, it is vital for muscle growth and can help people take their fitness to the next level.


Leucine is a branched-chain amino acid or BCAA. It has the greatest physiological effect of any of the BCAAs, the other two of which are isoleucine and valine.

This amino acid is naturally anabolic in the sense that it stimulates the release of human growth hormone, which in turn stimulates the growth of new muscle tissue. Like other BCAAs, it can be used medically to help heal wounds and for preventing muscle wasting.

In terms of fitness supplementation, most experts recommend taking the BCAAs together, but because leucine is most instrumental in muscle synthesis, it is generally recommended that users take twice as much leucine as each other BCAAs.

This is because the idea of taking BCAAs is to stimulate muscle protein synthesis, and the ratio of leucine to isoleucine and valine in muscle tissue is naturally about 2:1:1.

Supplementing with leucine and other BCAAs is especially helpful for bodybuilders who are on a cut and therefore consume fewer calories.

And while leucine is unquestionably the strongest BCAA, research has indicated that taking all three together has a stronger effect than leucine alone. This is part of why it’s virtually unheard of to see a leucine-only supplement on the market.

While leucine is commonly sold as part of bodybuilding supplements, it also can be found in food sources. It is available in virtually every protein source available, which means that most people already consume a fair amount of it already.

It is even found in food sources that only have small amounts of protein, like brown rice and whole wheat. While leucine is a vital part of everyone’s diet, it has additional benefits in terms of physique improvement and muscle growth for bodybuilders and fitness enthusiasts alike.


Lysine (lahy-seen, -sin) is one of three positively-charged amino acids. Amino acids are small molecules with an average molecular weight of about 135 daltons. All contain a central carbon atom that is linked on three sides to a hydrogen atom (-H), an amino group (-NH2), a carboxylic acid group (-COOH) and a uniquely defining ‘R’ group. The 20 most common amino acids form the structural basis of proteins.

Lysine is significant to the laboratory cell biologist. The enzyme trypsin, itself composed of a long string of amino acids, hydrolyzes other proteins wherever they encounter a lysine residue. Scientists use it to separate cultured cells from each other and from their flasks, enabling them to be divided and propagated.

Lysine is one of eight essential amino acids, meaning it cannot be manufactured in the body and must be taken in as part of the diet or as a nutritional supplement. The function of lysine in the human body is to:

– Build muscle and collagen.
– Promote the absorption of calcium from the intestine.
– Facilitate synthesis of antibodies, enzymes, and hormones.
– Increase creatinine production. Creatinine helps the body convert fatty acids into usable energy forms and reduces levels of LDL, the so-called ‘bad’ cholesterol.

Lysine is taken as a supplement to alleviate the symptoms of shingles (caused by the herpes zoster virus), and cold sores and genital herpes (caused by the herpes simplex virus). Some people take it to support immune and respiratory function, assist weight management and development of lean muscle mass, or to promote the health of teeth and bones.

In summary, lysine is an essential amino acid and cannot be synthesized by the human body. It has several functions in human physiology and may also be used as a chemical screwdriver in the laboratory.


Methionine is one of two amino acids that contain sulfur. The other is cysteine, which relies on methionine to provide its S atom. Because methionine cannot be synthesized in the body, it is an essential amino acid.

As long as cysteine has a steady supply of methionine, it is not regarded as essential in this context. Methionine is a vital source of sulfur, a key element in the nucleic acids, DNA and RNA.

As mentioned above, methionine provides a source of sulfur for the amino acid cysteine and for the production of nucleic acids. It has other important roles in human physiology.

– Methionine plays a huge role in our lives as a critical part of a molecule called S-adenosyl methionine (SAMe, or SAM, for short). SAM is a key player in the Methylation Cycle, a life-critical process involving the transfer of one-carbon methyl groups (-CH3) from one compound to another.
– Methylation occurs in all cells of the body and is crucial for immune function, detoxification, energy production, mood balancing, gene regulation and controlling inflammation.
– Methionine is important for the growth of new blood vessels, a process called angiogenesis.

A healthy adult should consume about 19 mg of methionine per kilogram per day. If you have allergies, a liver condition or frequent urinary tract infections, then a methionine supplement may help. These conditions create high demands for the amino acid.

Methionine is also sometimes used to treat depression. In cases of acetaminophen poisoning, methionine is administered to prevent liver damage.


Phenylalanine is an aromatic amino acid, a reference not to the way it smells, but to the six-carbon aromatic ring contained in its structure.

It occupies a pivotal position in human metabolism, serving as a precursor for the amino acid tyrosine, the skin pigment melanin, and the monoamine neurotransmitters adrenalin (epinephrine), noradrenaline (norepinephrine) and dopamine. Because phenylalanine can be manufactured by the body, it is not one of the essential amino acids.

Phenylalanine is converted in the liver to tyrosine, itself converted in neurons to dopamine and noradrenaline, hormones which are depleted by stress, exhaustion or by the action of certain drugs.

Phenylalanine therefore indirectly enhances mental energy levels and makes people feel emotionally calm and content.

People who cannot break down phenylalanine accumulate the amino acid to toxic levels, leading to a condition called phenylketonuria (PKU) and brain damage.  At around five days of age, newborns are tested for PKU.

Treatment involves a special diet and regular blood tests. Unfortunately, “special diet” means eliminating phenylalanine, which is present in dairy products, meat, and eggs. It is also found in products that contain the artificial sweetener aspartame.

Fortunately, the risk of brain damage and learning difficulties diminishes after the age of about 12, although adults who maintain a low-protein diet function better.

Phenylalanine is available in a powder, tablets or capsules. Individuals who do not have PKU take these supplements for:

– Depression
– Attention-Deficit Hyperactivity Disorder (ADHD)
– Chronic pain
– Parkinson’s disease
– Osteoarthritis
– Rheumatoid arthritis
– Alcohol withdrawal symptoms

Some individuals apply it directly to the skin for relief of the symptoms of vitiligo, a skin condition.


Threonine (three-uh-neen, -nin) is an alpha amino acid, one of the structural building blocks of protein molecules. An alpha-amino acid contains a central carbon atom surrounded by an amino group (-NH2), a hydrogen atom (-H), a carboxylic acid group (-COOH) and a unique ‘R’ group (-R) that distinguishes it from the other amino acids.

Because the ‘R’ group in threonine consists of a hydroxyl group (-OH), it is known as a polar amino acid. Threonine is also one of the essential amino acids and therefore ingested as part of the diet or as a supplement because it cannot be synthesized in the body.

Threonine is converted to another amino acid, glycine, which works within the brain to combat muscle spasticity. It is no good administering glycine itself because it cannot cross the blood-brain barrier. Threonine also:

– Maintain proper protein balance in the body.
– Promotes cardiovascular, liver, immune and central nervous system function.
– Maintains elasticity of blood vessels.

Symptoms of threonine deficiency include digestive problems, emotional agitation, confusion and fatty liver.

Threonine is available as a powder or in tablet or capsule form. The standard dosage is between 103 and 500 milligrams daily. Exceeding the recommended dose can cause ammonia toxicity and disrupt liver function.

People take threonine primarily to treat nervous system disorders such as multiple sclerosis, amyotrophic lateral sclerosis (ALS, Lou Gehrig’s disease), spinal spasticity or familial spastic paraparesis.

In summary, threonine is a polar essential amino acid. It is used to treat central nervous system problems, especially those that cause muscular spasticity.


Tryptophan is an amino acid that the human body does not naturally produce. Instead, it is acquired by eating certain dairy products, such as milk and cheese.

Tryptophan is also found in chicken, eggs, turkey, soy, tofu, peanuts, sesame seeds, sunflower seeds, pumpkin seeds and chocolate. Tryptophan can also be purchased over-the-counter as a supplement.

The body uses tryptophan to make serotonin, a neurotransmitter. Serotonin sends signals between nerve cells, which probably accounts for its ability to impact a person’s mood.

Because serotonin has the power to influence mood, tryptophan is often purchased in pill form to combat insomnia and depression.

Along with riboflavin, vitamin B6 and iron, tryptophan works to produce niacin, a compound essential to many bodily processes. Lack of niacin in the body may lead to anemia, nausea, headaches, and fatigue.

Because serotonin and tryptophan are often tied to affecting a person’s mood changes, tryptophan is often used to treat the following conditions:

– Depression
– Anxiety
– Insomnia
– Sleep apnea
– PMS and premenstrual dysphoric disorder (PMDD)
– Attention deficit-hyperactivity disorder (ADHD)

In addition to treating the above conditions, tryptophan is also used to treat certain behaviors, such as helping a patient quit smoking or preventing a person from grinding his or her teeth while sleeping. Scientists are currently researching other possible uses for tryptophan.


Valine is one of three branched-chain amino acids or BCAAs. The “branched” refers to the fact that the molecular structure has several branches.

The BCAAs are integral components of muscle tissue, and supplementing with them or obtaining them through the diet can help to support general health as well as to support muscle growth.

Valine is found naturally meat, dairy, mushrooms, grains, and even in peanuts and soy.

While getting enough valine in the diet is important, additional supplementation of valine along with the other two BCAAs can help with muscle repair, which in turn can lead to greater muscle hypertrophy.

It is important to take the BCAAs together, as they exist naturally in muscle tissue at a leucine: isoleucine: valine ratio of about 2:1:1.

Additionally, research has shown that over-supplementing one and not the other two may even lead to a deficiency of one of the others in the body.

While valine needs to be taken alongside other branched-chain amino, it does have some unique benefits of its own. Valine helps the body use glucose, and it also can help you preserve nitrogen balance.

Nitrogen balance refers to the ratio of nitrogen consumed to nitrogen excreted, and it is very important for anyone trying to build muscle. If you are excreting more nitrogen than you consume, your body is breaking down muscle tissue, which is something to avoid.

One important point regarding valine is the fact that a deficiency can lead to serious health issues. For most people, becoming deficient in valine is very unlikely, but a deficiency may lead to the development of maple syrup urine disease or MSUD.

In short, while valine is a vital part of everyone’s diet and is important for general health, supplementing with it alongside other branched-chain amino acids can help support muscle growth and repair for anyone trying to improve their physique.

Non-Essential Amino Acids

To the uninitiated, non-essential amino acids may sound like unnecessary amino acids. However, the term “non-essential” just means that these amino acids are produced by the body.

While they are also found in foods, they are not present to the degree that essential amino acids, or amino acids not produced by the body, are. There are 11 non-essential amino acids that are produced by the body when needed.

These amino acids are important to the body because they are one of the major building blocks of proteins, and your body needs them for virtually every aspect of metabolism.

Although the body can make non-essential amino acids, this is contingent upon your consuming all of the essential amino acids, as well as consuming enough of them.

Your body does not store amino acids as it does fat, so it is important to eat enough essential amino acids daily.

Each non-essential amino acid has its own unique function that supports general health and wellness. For instance, cysteine can help protect the liver, and it also helps with insulin release, and arginine can help increase gains in muscle mass while also improving workout performance and reducing fat.

Glutamine is often taken as a muscle recovery supplement, and it can help provide the body with energy when glucose is relatively scarce.

Although the health benefits of non-essential amino acids are diverse and vary between the different amino acids, their health benefits all share the commonality of optimizing a host of metabolic functions.

While the body can make these amino acids from essential amino acids, certain health issues and other adverse events may negatively impact your body’s ability to produce them.

Some people prefer to also make an effort to obtain these amino acids through diet or supplementation. This can be especially helpful if you are dieting or if your diet does not have a lot of variety, as missing even one essential amino acid can adversely affect your ability to produce and use the non-essential amino acids.


Amino acids found in humans assist in all life processes, especially ones involving protein construction and metabolism. Alanine, an amino acid that helps convert glucose into energy for bodily functions while eliminating toxins, like nitrogen, from the liver, is nonessential. This simply means that a healthy body can manufacture a supply of alanine without help.

During the alanine cycle, excess proteins in cells and tissues are sent to a receptor molecule known as pyruvate, something produced during the breakdown of glucose.

Pyruvate is converted into alanine and transferred to the liver, where nitrogen is extracted before converting some of it back to its original form of pyruvate.

This step allows more glucose to be produced. Excess nitrogen is classified as waste and is passed through the body during urination. This process ensures a constant supply of pyruvate, resulting in the healthy mixture of amino acids and glucose throughout the body.

Being an important source of energy for muscles and the central nervous system, alanine plays a crucial role in preserving balanced levels of glucose in the body.

In addition to this, alanine strengthens the immune system, reduces cholesterol levels, and has even been associated with regulating blood sugar.

Low levels of alanine can be dangerous and have been found in patients with hypoglycemia, diabetes, and hepatitis. Many things like poor nutrition, environmental factors, a low protein diet, and even stress can lead to a deficiency of alanine.

Luckily, there are various supplements containing alanine that are available over the counter. Fish, eggs, dairy products, and some protein-rich plant foods, like avocados, are also good sources of alanine.


Arginine is an amino acid that is commonly used as a sports supplement. Generally, it is sold in the form of L-Arginine, which is used to increase the body’s production of nitric oxide.

Arginine has been used in the fitness community for years, and it was used to increase workout performance even before users knew exactly how it worked.

A team of researchers opted to study the effects of arginine and found that it increased nitric oxide production, which in turn led to a dilation of blood vessels and increased blood flow to working muscles.

This study ultimately won the 1998 Nobel Prize in Medicine, and it validated the fitness community’s long-standing belief that arginine was helpful for sports performance.

But how exactly does vessel dilation improve sports performance? To start, since blood delivers both oxygen and nutrients to the body’s tissues, it helps ensure that muscle tissue is adequately oxygenated.

This is important when exercising- if you’ve ever felt a benign sensation as you begin to get tired, you know what it feels like when muscle tissue is no longer getting enough oxygen.

The delivery of nutrients is also important, especially if you take supplements like creatine. Since many workout supplements are designed to increase explosive power when lifting, taking arginine can help make sure your muscle tissue receives these supplements quickly.

Arginine is also helpful for muscle recovery since it expedites the delivery of your post-workout meal to your muscle tissue.

Arginine’s stimulation of nitric oxide is safe for the body because, although it increases blood flow, it also dilates blood vessels, which means that blood flow is increased without increasing blood pressure.

Exercise, and especially strength training, already temporarily raises blood pressure, so a further spike could potentially be dangerous.

Amino acids are essential for basic health and wellness. However, arginine has several benefits and advantages specific to athletic performance. Therefore, it is commonly seen in pre-workout supplements and other athletic formulations.


Asparagine is all about balance. This amino acid is important in balancing the central nervous system — one sign of an asparagine deficiency is a temperament that is inexplicably too calm or too nervous.

It is also important to the immune system: other signs of deficiency include fatigue, susceptibility to infection, or severe allergic reactions.

Besides keeping the central nervous system in balance and supplementing the immune system, asparagine is also important for building proteins (including muscle) in the body.

This is why a deficiency in asparagine can cause fatigue. Supplementation of asparagine has decreased the levels of fatigue in athletes while increasing concentration and focus.

It also helps the body to transport nitrogen: without this function, the body would build up too much urea, which could cause mental problems, including depression, irritability, and even psychosis.

If the body has enough asparagine, the liver will use the excess amino acid to make other necessary amino acids, especially aspartic acid, which is important for metabolism and the removal of excess ammonia.

Asparagine is a non-essential amino acid, which means that under normal conditions, the body can manufacture it on its own — so a diet lacking in it will not necessarily affect a person.

However, sometimes the body may need more asparagine than it can make. In these cases, a person can take a supplement, or eat foods rich in asparagine.

These foods include dairy, poultry, nuts, whole grains, asparagus, beef, and fish.

Aspartic Acid

In the body, protein is made of a variety of “building blocks” called amino acids, arranged in endless combinations to create the structure and functionality that drive all of our biological processes.

Aspartic acid is a particular amino acid, and a further subclass is D-aspartic acid (DAA – referring to a specific molecular shape). In recent years, DAA has gained some press as a health supplement.

What does DAA do?

Naturally produced DAA works with the central nervous system to regulate the production of testosterone through communication with a complex network of other hormones.

The D-form we are talking about is not an actual building block, but a signaling device to other cellular structures to start the building process.

What does DAA supplementation do?

Some companies market DAA as a body-building supplement for men, citing the testosterone boost as a vehicle for muscle stacking.

Limited research so far has not shown any benefit for DAA as a workout supplement, as there was no evidence of weight gain or increase in muscle mass, but have proven positive for a temporary increase in testosterone levels.

The increased testosterone was accompanied by increases in sperm motility and male fertility as well. Although more in-depth research is needed, DAA does seem to help with male fertility issues.

Is DAA safe?

The short answer is…maybe. No harm was demonstrated in the studies, which used the recommended dosage of 2000 to 3000 mg.

It could be used as a natural alternative to prescribed testosterone gels and injections for men who suffer low levels of the hormone or are having trouble conceiving a family.

Since elevated testosterone levels come with their own health risks, it’s wise to check with your doctor before supplementing DAA for any reason.


Cysteine is the beauty amino acid. It is essential for the formation and maintenance of skin, hair, and nails. It is used to make collagen, which ensures that skin has the right elasticity and texture. Researchers believe that cysteine can slow the aging process.

But there’s more to cysteine than just keeping you beautiful: it also defends the body against toxins we take in through with our food, drugs, and air. When cysteine is taken in conjunction with selenium and Vitamin E, it is an incredible warrior against free radicals.

Free radicals do more than just damage skin: they are also a major factor in cancer, heart disease, kidney disease, asthma, dementia, and many other ailments. The body transforms cysteine into glutathione, which is a powerful antioxidant.

Cysteine is a non-essential amino acid, which means that the body can manufacture its own cysteine under normal circumstances.

Deficiencies in cysteine are rare, but they can happen in vegetarians and people who do not get enough protein in their diet.

Some symptoms of cysteine deficiency include decreased pigmentation in hair, skin lesions, muscle loss and weakness, liver damage, and lethargy.

Cysteine deficiencies can be addressed through supplements or diet. Foods that contain cysteine include chicken, turkey, oatmeal, granola, yogurt, cottage cheese, and lunch meats.

Although cysteine is good for the body, it is important to discuss supplementation with your doctor, as it can interact poorly with other medications.

Too much cysteine can cause nausea, drowsiness, and low blood pressure. These side effects are rare and usually the result of excessive supplementation, but it is important to be aware of them.

Glutamic Acid

Glutamic acid is a non-essential amino acid. This means it’s naturally occurring in the body, and it doesn’t need to come from outside sources.

It functions in the central nervous system as an excitatory neurotransmitter and has many health benefits for the immune and digestive systems.

Glutamic acid is also involved in the synthesis of glutamine, another amino acid essential for muscle health, glutamates, which are derivatives of glutamic acid with varying functions, and GABA, an inhibitory neurotransmitter.

Glutamic acid is essential to the health of the brain and spinal cord. In the central nervous system, it’s the most prevalent excitatory neurotransmitter.

It promotes energy, memory, and mental alertness. Glutamic acid is sometimes used to treat mood disorders, such as bipolar, anxiety, schizophrenia, etc. because they have been linked to low GABA levels in the brain. Since it promotes mental acuity, it is sometimes used to treat attention disorders too.

Other parts of the body benefit from glutamic acid too. The synthesis of glutamine from glutamic acid cleanses the body by removing toxic ammonia. Glutamine itself is used by muscles and is essential to their growth and health.

Glutamic acid and its derivatives are also implicated in immune health, prostate health, heart function, and digestive health. It is also said that it helps control cravings for sugar and alcoholism.

Glutamic acid is essential for a healthy body. It has many important roles, and it performs them all admirably. Whether it’s the head or the heart, glutamic acid is fundamental to its function.


Glutamine is an amino acid, which is a key building block for proteins that are found naturally in the human body. Glutamine is actually the most common amino acid found in the bloodstream and accounts for roughly 30-35% of the amino acid nitrogen found in your blood.

This makes it a conditionally essential amino acid because of the large amounts of it used consistently by the human body.

Glutamine has many uses and health benefits. It improves gastrointestinal health by being an important nutrient needed by the intestines to both rebuild and repair themselves.

Glutamine acts as the main fuel source for cells in the small intestine, which helps combat symptoms of ailments like leaky gut syndrome and irritable bowel syndrome. It also helps heal ulcers by acting as a patch for protection from further damage caused to the affected area.

Glutamine is also a key neurotransmitter in the brain. This means it helps with focus, concentration, and also memory retention.

Like other proteins, Glutamine helps promote muscle growth and decrease waste, which leads to an increase in athletic performance and faster recovery times from training and exercise. It basically acts as a kind of buffer and converts excess ammonia into other amino acids, amino sugars, and urea.

Its dietary benefits also include improving metabolism and cellular detoxification, while helping curb cravings for alcohol and sugar. Studies have shown that glutamine helps promote human growth hormone as well, which aids fat metabolism and new muscle growth.

Glutamine also helps fight cancer and improve blood sugar, which combats diabetes. Ingesting supplemental glutamine helps strengthen the immune system and is known to help fight the side effects of cancer treatments like chemotherapy.


Glycine is a glucogenic amino acid. This means it helps to supply glucose that is later converted to energy in the human body. It is a building block for protein, and humans make it naturally from other chemicals. Glycine is found in foods that are high in protein, including milk, cheese, fish, meat, peas, beans and other legumes.

This amino acid is also found in supplements, including capsules and powders. Glycine can be consumed by mouth or applied to the skin to treat certain bodily ailments.

Glycine is used by the body to make protein. It helps form muscle tissue and transforms glucose into energy. Some researchers theorize that glycine may help prevent cancer because it appears to impact the blood supply that is essential in some tumors via antioxidants.

Glycine is often used for the following purposes:

– To treat stroke patients
– Aid in muscle growth
– To treat skin ulcers
– Repair joints and cartilage
– To treat schizophrenia

Researchers also believe glycine has many protective properties. For instance, glycine is used to protect kidneys from the detrimental side effects of many drugs. Those who consume large quantities of alcohol might also be given glycine as a means of protecting a damaged liver.

Glycine helps transmit chemical signals in the brain, which is why some believe it aids in improving memory. It is often used as a memory enhancer and to treat sleep disorders in patients who are fatigued or suffer from Parkinson’s or Huntington’s disease.

Glycine can be converted into serine, a neurotransmitter, some researchers believe it can aid in treating schizophrenia.


Tyrosine is an amino acid that can be made naturally by the human body. It is made from phenylalanine, another amino acid. Tyrosine is found in certain foods, such as dairy products, oats, wheat, fish, meat, nuts, eggs, and beans.

Tyrosine is used in the human body to make chemical messengers involved in processes concerning the brain. Tyrosine is believed to support mental alertness. Thus, people often take it to improve mental functioning and focus.

Tyrosine is also used in protein supplements to treat phenylketonuria (PKU), an inherited disorder. People with PKU can’t process phenylalanine efficiently, so they are unable to make tyrosine. To meet their bodies’ needs, they take supplemental tyrosine.

Tyrosine is taken for a number of health problems and conditions, including the following:

– Depression
– Attention Deficit Disorder
– Attention Deficit-Hyperactivity Disorder
– Stress
– Parkinson’s
– Alzheimer’s
– Premenstrual Syndrome
– Drug Withdrawal Symptoms
– Schizophrenia

It has also been used to treat sleep problems, such as narcolepsy or to improve alertness in patients who suffer from sleep deprivation.

Tyrosine is also sometimes used to treat chronic fatigue syndrome (CFS), stroke and heart disease. Sexual disorders such as erectile dysfunction and the loss of sexual appetite are also often treated with tyrosine.

However, there is still some debate about whether or not tyrosine can effectively treat any of the aforementioned conditions.


Proline (pro-leen) is an amino acid, one of 20 building blocks that make up the proteins in the human body. Proline is one of the most abundant amino acids, second only to alanine and glutamine.

If you were paying attention in biology class, you might remember that proline has a reputation as a ‘helix-breaker,’ meaning it has a key role in shaping structural features of proteins such as alpha helices and beta-pleated sheets.

Present in nature in L- and D- forms, depending on the way it interacts with polarized light, it is only the L-form that is any use to us.

In the human body, proteins that contain high levels of proline:

– Repair damaged tissue
– Maintain blood pressure
– Prevent atherosclerosis
– Build collagen, necessary for skin, tendons, ligaments, and muscle

L-proline is commercially available in capsule form or as a powder. People who need to take a proline supplement for medical reasons include those who have spent prolonged periods in institutions where they have not had access to an adequate diet, in particular, diets that are low in protein.

L-proline may also help those individuals who have a wound that is not healing properly. People with chronic injuries and illnesses have problems synthesizing enough proline. Individuals with fine lines and wrinkles also use proline, either orally or as a topical preparation.

If you are taking proline to promote collagen formation, you should take it alongside supplements containing vitamins B, C, and niacin. This is because the enzymes that incorporate the amino acid into collagen depend on these nutrients.

Atherosclerosis is caused by the buildup of fatty deposits on the inner walls of the arteries nearest the heart. Proline allows the blood vessels to release these clumps of fat into the bloodstream, thereby reducing the size of the blockages and helping to protect against heart disease.

To summarize, L-proline is an amino acid that is present in almost every protein in the human body.

Although it is manufactured from other amino acids and ubiquitous in the diet, there are times when it is necessary to take a proline supplement.


The amino acid serine is a substance that your body produces by combining the amino acids, glycine, and threonine. You need serine for your brain and central nervous system to function properly.

Serine plays an important role in your body.

– It makes up the phospholipids, which are necessary for creating all of your cells
– It also assists with RNA and DNA functions, as well as the metabolism of fatty acid and fat, forming muscles, and maintaining the health of your immune system
– It helps to make creatinine that works together with water to build muscles
– It lets you fight infections as a significant aspect of antibodies and immunoglobulins
– It also helps the myelin sheaths to protect your nerve cells; they would fray and become incapable of sending messages between the brain and nerve endings

To stay healthy, you need serine for the production of tryptophan; it is the amino acid responsible for serotonin. Serotonin is necessary to stabilize your moods.

When your level of serine is low, it causes anxiety and depression, along with confusion and insomnia. When you have enough serine, you will have a healthier immune system and stronger muscles, which includes your cardiac muscle.

The non-essential amino acid, serine, is a major player in your overall health.