Glycine: Definition, Benefits, Sources, Uses, Risks, Classification and Amino Acid Deficiency

It is one of the 20 amino acids used to make proteins in the human body. The body produces it naturally.

While you may not be familiar with the term precisely, use glycine every day to strengthen your body and, frankly, allow it to function correctly.

This amino acid is essential for much different muscle, cognitive and metabolic functions.

Glycine can help reduce symptoms in people suffering from ulcers, arthritis, leaky gut syndrome, diabetes, kidney and heart failure, neurobehavioral disorders, chronic fatigue, sleep disorders, and even certain cancers.

Amino acids such as glycine can be found in supplement form, but it is easy, and probably even more beneficial, to acquire them from natural food sources.

It helps to break down and transport nutrients such as glycogen and fat to be used by cells as a source of energy, and in the process, it is compatible with solid immune, digestive and nervous systems.

In the human body, glycine is found in high concentrations in the skin, the connective tissues of joints, and muscle tissue.


Glycine is the second most widespread amino acid found in human enzymes and proteins, and that is why it has functions in almost every part of the body.

It is one of the 20 amino acids used to make proteins in the body, which forms the tissue that forms the organs, joints, and muscles.

People who are sick, recovering from surgery, taking medications that hinder specific metabolic processes, or are under much stress can use additional glycine for recovery.

Of the proteins in the body, it concentrates on collagen (the most abundant protein in humans and many mammals) and gelatin (a substance made of collagen).

Some of the most attractive attributes include promoting better muscle growth, healing the gastrointestinal tract lining, and slowing down cartilage loss in the joints and skin.

Glycine is also found in protein-rich foods such as:

  • Meat.
  • Fish.
  • Dairy products.
  • Vegetables.

It is estimated that we get approximately 2 grams of glycine per day from food sources. As a supplement, it is taken in much higher amounts.

Glycine was discovered in 1820 by Henri Braconnot when he hydrolyzed the gelatin by boiling it with sulfuric acid. Originally he called it “gelatin sugar,” but a Liebig student showed that it contained nitrogen, and Berzelius renamed it “glycine.”

The name comes from the Greek word γλυκύς “sweet flavor” (which is also related to the prefixes glycol- and glycol-, as in glycoprotein and glucose). Another early name for glycine was “Glycocoll.”

Chemical Raw Materials

Glycine is an intermediate in the synthesis of a variety of chemical products. It is used in the manufacture of glyphosate herbicide.

Laboratory Research

Glycine is a significant component of some SDS-PAGE protein analysis method solutions. It serves as a buffering agent, maintains the pH, and prevents damage to the sample during electrophoresis.

Glycine is also used to remove antibodies labeled with proteins from the Western blot membranes to allow probing of numerous proteins of interest from the SDS-PAGE gel.

This allows more data to be extracted from the same sample, increasing the reliability of the data and reducing the amount of sample processing and the number of pieces required. This process is known as stripping.

Health benefits

There are numerous health benefits of glycine. New research is coming out all the time that shows the importance of this amino acid! These are just some of the main advantages of glycine to know.

It has many proposed uses. Few of the suggested services have enough evidence to support glycine’s effectiveness fully.

Some of the many health benefits of glycine include:

  • It helps build lean muscle mass.
  • Prevents muscle loss, muscle wasting, or deterioration.
  • It plays a role in the production of human growth hormones.
  • Increase mental performance and memory.
  • It helps to prevent strokes and attacks.
  • Protects the skin from the signs of aging or cell mutations.
  • Protects collagen in the joints and reduces joint pain.
  • Improves flexibility and range of motion.
  • Stabilizes blood sugar and decreases the risk of type 2 diabetes.
  • It enhances sleep quality.
  • Reduces inflammation and free radical damage by increasing glutathione production.
  • It reduces the risk of certain types of cancer.
  • Build the lining of the gastrointestinal tract.
  • It produces bile salts and digestive enzymes.
  • It helps reduce allergic and autoimmune reactions.
  • Increase energy levels and fight against fatigue.
  • It helps to make red blood cells.
  • Fight against the effects of stress and anxiety.
  • It helps control the symptoms of seizures, schizophrenia, and mental disorders.

Glycine has proven to be the most promising part of a treatment plan for schizophrenia. In several studies, glycine increased the effectiveness of other medications for schizophrenia when taken in doses ranging from 15 grams to 60 grams per day.

However, glycine can have the opposite effect when combined with the antipsychotic drug clozapine.

A small study suggests that glycine can help people with type 2 diabetes control their blood sugar levels. However, more research is needed to support that result.

In a much larger study, small doses of glycine (1 to 2 grams dissolved under the tongue) showed some potential to limit brain damage caused by ischemic stroke if the treatment starts within several hours of a stroke.

However, there is some concern that high doses of glycine can worsen the damage caused by a stroke.

Studies in animals hint at the potential of glycine as an anticancer agent. However, there is still no evidence that it can help prevent or treat cancer in people.

The same can be said of its ability to protect the liver and kidneys from damage caused by chemicals such as alcohol.

The leg ulcers, caused by poor circulation, diabetes, renal failure, and other health problems, have shown some improvement after treatment with a cream containing glycine and other amino acids.

One study showed an improvement in memory among young and middle-aged men. However, the results must be confirmed by more research.

Glycine is also marketed for several other uses, despite the lack of scientific evidence that it is effective or safe. For example, glycine is sold as a form of:

  • It promotes the healing of muscles that are overworked or damaged.
  • Soothe stomach upset
  • It promotes calm and relaxation.
  • It boosts the immune system.
  • Increases human growth hormone.
Glycine Regulates Sugar in the Blood

Blood sugar is not just a problem for people with diabetes. When you eat foods high in sugars (glycemic load), your body produces insulin. The increase in insulin in the bloodstream causes the body to stop burning fat and instead store those extra calories as fat.

It increases your risk of diabetes, but those increased insulin levels are essential for gaining weight!

Glycine helps by stimulating glucagon to help eliminate insulin from circulation. It can also decrease the intake of free fatty acids in the blood and reduces glycosylated hemoglobin.

There is much scientific research to support the benefits of glycine in fighting diabetes. One of the most exciting findings is that people with diabetes have glycine levels 26% lower than non-diabetics.

Therefore, if you have high/low blood sugar levels, it could be a sign that you need more glycine in your diet!

Glycine Improves Sleep

One of the best benefits of glycine is that it can help you sleep well and reduce fatigue.

Several studies have shown that taking only 3 grams of glycine before sleep improves sleep quality, reduces sleep disturbances, and enhances well-being the next day. These benefits are likely due to the role of glycine as an inhibitory neurotransmitter.

Due to its role in the central nervous and digestive systems, glycine can help increase energy levels, balance blood sugar, and prevent fatigue.

It can even be used to calm the anxiety or nervousness that keeps you awake at night and hinders good sleep.

In addition, it helps carry nutrients to cells and tissue for energy at all times of the day; glycine supplements improve sleep quality, reduce daytime sleepiness and improve the performance of memory recognition tasks.

One of its most important functions is to help carry out heme biosynthesis, a component of hemoglobin that helps produce and maintain red blood cells. Red blood cells help carry oxygen throughout the body, promote cellular functions and provide energy to the tissue, heart, and brain.

Glycine is often used in supplements designed to improve energy in athletes, combat fatigue caused by anemia, and help regulate blood sugar levels.

Another way glycine can improve sleep is by increasing the absorption of magnesium. Magnesium is an excellent cure for insomnia because it calms the body. Approximately 15 percent of the general public is deficient in magnesium.

If you have trouble sleeping, you may consider taking a magnesium supplement to treat insomnia.

Combat the Signs of Aging

We could easily fight the signs of aging by improving our diet.

Glycine is essential to fight age because it is one of the main components of collagen. Collagen is what makes our skin elastic. We get wrinkles when the collagen breaks down.

Glycine helps form glutathione, a valuable antioxidant used to prevent cell damage and various signs of aging.

Although glutathione deficiency in the elderly occurs due to a marked reduction in synthesis, supplementation with the glutathione, cysteine ​​, and glycine precursors completely restores glutathione synthesis.

This helps increase concentrations and decreases the levels of oxidative stress and oxidative damage that lead to aging.

In certain studies, it has even been found that glycine helps prevent cell mutations that lead to cancer.

There is some evidence that targeted amino acid therapy can prevent the growth of cancer cells by cutting off their energy supply and helping to reduce inflammation, which is related to many other chronic conditions besides cancer.

Supports Digestive Health

Glycine is crucial to maintaining the intestinal wall and its mucosa. If you have a disorder such as intestinal bacterial overgrowth or leaky gut in which your bowel is damaged, glycine can help heal your intestinal lining.

Glycine helps heal ulcers and regulate gastric acids.

In an animal study, glycine was able to prevent colitis by inhibiting inflammation. Therefore, glycine could be helpful in the treatment of inflammatory bowel disease.

Amino acids, including glycine and proline, help rebuild the tissue lining the digestive tract, keeping food particles and bacteria inside the intestine where they belong instead of allowing small openings to form that pass particles into the bloodstream where they trigger the inflammation.

Glycine helps form two essential substances that make up the intestinal lining: collagen and gelatin.

Collagen and gelatin help people with food allergies and sensitivities to tolerate food more efficiently.

It can soothe the lining of the GI tract in people with inflammatory bowel disease or indigestion (including leaky gut syndrome, IBS, Crohn’s disease, ulcerative colitis, and acid reflux) and even promote probiotic balance and growth.

Within the gastrointestinal tract, glycine also acts as a metabolic fuel. It is necessary to make bile, nucleic acids, creatine phosphate, and porphyrins that will be used to break down the nutrients in your diet.

For example, it helps break down fats by assisting with the production of bile acids and allows glycogen transport to cells to be used as energy in the form of ATP.

The evidence also shows that glycine can help stabilize blood sugar levels, which leads to more lasting energy and avoids sugar cravings and fatigue.

Build Muscle

Glycine is essential for synthesizing creatine, a substance in the body that is crucial in providing energy to the muscles to gain strength and mass. Many bodybuilders supplement with creatine for this reason.

It has been found that glycine helps inhibit the deterioration of the valuable protein tissue that forms the muscle and increases muscle recovery.

It is known as an “anti-aging amino acid” because it helps maintain lean muscle mass in old age.

It stimulates the secretion of human growth hormone, prevents the loss of cartilage in the joints, and even improves daily energy and physical performance, and mental abilities (all-important for athletes).

Glycine is used during the biosynthesis of creatine, which provides the muscles with a direct source of fuel to repair the damage and grow stronger again.

It also helps to provide energy to cells thanks to its role in converting nutrients from your diet, helps to feed hungry muscle tissues, and increases endurance, strength, and performance.

It also benefits the production and regulation of hormones, which helps the body naturally synthesize the steroid hormones that regulate the relationship between fat and muscle mass and control energy expenditure.

Repairs and Protects the Joints and Cartilage

Along with other amino acids found in bone broth (especially proline), glycine plays a role in collagen formation, promoting the growth and function of joints, tendons, and ligaments.

Approximately one-third of the collagen is composed of glycine, and collagen is crucial to forming the connective tissue that keeps the joints flexible and withstands shock.

This is why collagen hydrolyzate is often used to treat degenerative joint diseases such as osteoarthritis.

As people age, it is essential to consume enough proteins (amino acids) to repair damaged tissues in the joints that suffer from the continuous damage of free radicals.

Glycine is essential for forming flexible and elastic cartilage, helps heal damaged joints, and can prevent loss of mobility and functionality in older adults.

Help for Mental Health

Glycine is not only an amino acid; it is also a neurotransmitter that has its signaling system. It is considered one of the most important inhibitory neurotransmitters! In other words, glycine keeps our brains calm.

Due to its inhibitory actions, it has been scientifically proven that glycine helps several mental health problems, which include:

  • Obsessive-compulsive disorder
  • Depression .
  • Schizophrenia.
  • Dysmorphic disorder of the body.

Again, there is no reliable evidence that it works for such uses.

The optimal therapeutic doses for glycine have not been established for any condition. In addition, as with supplements in general, the quality of the active ingredients in products containing glycine varies from manufacturer to manufacturer.

Calm the Nerves and Feed the Brain

Glycine is beneficial in supporting cognitive performance and the central nervous system. It helps regulate the metabolic synthesis of certain nutrients that the brain and nerves use for energy.

It helps regulate nerve impulses throughout the body by balancing electrolyte levels, such as calcium, chloride, and potassium.

Due to its role in nerve functions and neurotransmitters, glycine also has implications for helping improve sleep, mental performance, body sensations, mood, memory, and behaviors.

For example, as an inhibitory neurotransmitter, glycine works with other amino acids, including taurine and gamma-aminobutyric acid (GABA).

Some evidence shows that glycine can help reduce hyperactivity in the brain and even play a role in treating or preventing mental disorders, including learning disorders, schizophrenia, bipolar disorder / manic depression, and epilepsy.

Studies have shown that glycine helps reduce psychotic symptoms, strokes, and seizures when used with other supplements as part of a comprehensive treatment plan for mental/cognitive disorders.

Glycine Helps Joint Health

Our joints are composed mainly of cartilage. Moreover, what is the cartilage made of? You guessed it! Glycine is one of the primary amino acids that form our joints.

Glycine and the amino acids proline and hydroxyproline from our joints’ complex chains of proteins. If you do not have any of these amino acids, your body will not be able to produce more cartilage or keep the joints properly lubricated.

Considering that 19% of Americans have chronic joint pain, it is common sense that we could benefit from consuming more glycine.

Can You Get Glycine from Food?

Foods rich in protein provide small amounts of glycine. However, supplements are required to obtain glycine in high doses.

Getting more glycine in your diet is probably even easier than you think. Bone broth is an excellent source of natural glycine, and other amino acids are inexpensive, easy to prepare at home, and have long-term health benefits.

Bone broth, made from simmering animal parts, including bones, skin, and tendons, contains natural collagen, releasing essential amino acids and other substances often lacking in the typical Western diet.

However, if you are not willing to consume bone broth, for example, vegetarian or vegetarian, glycine can also be obtained from plant foods. Plant-based sources include beans, vegetables such as spinach, kale, cauliflower, cabbage, and squash, plus fruits like bananas and kiwi.

Glycine can also be found in “complete protein sources” (animal proteins), including meat, dairy products, poultry, eggs, and fish.

Do not forget that glycine is also found in large quantities in gelatin, a substance made from collagen used in certain food products and, sometimes, for cooking or preparing food.

Gelatin is not commonly consumed in large quantities, but it can be added to recipes when preparing desserts, yogurts, raw cheeses, or even ice cream.

Sources of Glycine

Many foods contain glycine. The best ones are meat, chicken and seafood. However, when it comes to natural sources of glycine, nothing beats gelatin!

Gelatin is the name of cooked collagen. It is usually made by boiling the connective tissues and bones of animals.

Collagen typically contains 22% to 30% glycine. By adding just two tablespoons of collagen to your diet, you will add approximately 3 grams of glycine to your diet. That is an excellent impulse!

Nutrition facts and facts about glycine:

  • While protein-rich foods (such as meat and dairy products) contain some glycine, the best sources, collagen and gelatin can be challenging to obtain.
  • These proteins are not found in most cuts of meat and, instead, are acquired by consuming parts of animals that today most people throw: skin, bones, connective tissue, tendons, and ligaments.

You so 

Food for animals and humans

USP glycine has many uses, including as an additive in pet food and animal feed, in food and pharmaceutical products as a sweetener/flavor enhancer, or as a component of food supplements and protein drinks.

Two glycine molecules in the form of dipeptide (glycinate) are sometimes used to improve the absorption of mineral supplementation. When they bind to a dipeptide, they can be absorbed through different transporters.

Cosmetics and various applications

Glycine is a buffering agent in antacids, analgesics, antiperspirants, cosmetics, and toiletries.

Various industrial and chemical processes use glycine or its derivatives, such as the production of fertilizers and metal complexing agents.

When it comes to glycine supplements and dosage recommendations, here is what you need to know:

While some foods (especially animal proteins and bone broth) provide some glycine, the amounts tend to be minor, so you should consume supplements if you want to get a higher dose.

There is no established daily requirement or an upper limit of glycine. It is believed that most people already get about two grams of glycine daily from their diets, but the needs differ greatly depending on the level of activity and health status of a person.

Depending on the symptoms you are trying to solve, you can benefit from consuming ten times the average amount or even more.

Not all protein/amino acid supplements are created equal; Always look for high-quality brands sold by reputable companies and consume food supplements whenever possible.

Because glycine is a natural amino acid, there is no risk of consuming too much of your diet. In supplement form, the highest doses of glycine, between 15-60 grams, have been used safely to help solve chronic diseases such as mental disorders. Still, this amount should be taken with the supervision of a doctor.

It is not known whether giving glycine supplements to children, pregnant or lactating women, or people with kidney or liver disease is safe or a good idea, so avoid using glycine in these cases for the time being.

When taken in high doses, glycine supplements may also interact with certain medications (such as those used by people with mental disorders, including clozapine).

Although, for most people, glycine is very safe (especially in the form of food), if you take medication, it is always a good idea to consult your doctor when you start using any supplement.

What are the risks of taking glycine?

Glycine appears to be safe, even at doses of up to 60 grams per day. However, the safety of glycine has not been thoroughly tested or studied. Particular caution should be taken when considering glycine for young children, pregnant or lactating women, and people with liver or kidney disease.

People who are treated with clozapine should avoid taking glycine. Also, people who have had a stroke should not take glycine without the supervision of a doctor.

Some people have reported nausea, vomiting, and upset stomach after taking glycine. Such reports have been rare, and the symptoms disappeared after stopping the administration of glycine.

You probably know about carbohydrates, fats, and proteins as a health-conscious person. You might even know what an amino acid is (the building blocks of proteins). However, few people understand what each of our amino acids does.

This is a shame because some amino acids can have enormous health benefits! One of these is the amino acid glycine.

Classification of glycine in amino acids

All amino acids can be divided into three types:

Essential: Amino acids that the body cannot produce and must be obtained through dietary sources.

Not essential: these amino acids can be produced by the body from other amino acids.

Conditional: Amino acids that the body can produce but will not necessarily have enough of (especially in stress, illness, or injury). Therefore, it may be necessary to consume them through dietary sources.

Glycine is made of the essential amino acids serine and threonine. It falls into the conditional category. However, some studies show that our bodies may not be able to produce enough glycine by themselves.

Glycine Deficiency

A 155-pound person would need approximately 10 grams of glycine per day to meet the needs. Our bodies (assuming you are getting enough serine and threonine) will produce about 3 grams per day. We get another 1.5 to 3 grams of the diet.

That adds up to 4.5 to 6 grams per day, well below the 10-gram requirement.

It is not clear how many people have a glycine deficiency (I could not find any study on the prevalence of glycine deficiency). However, the research clarifies that we could benefit by increasing our dietary glycine intake.

Glycine is found mainly in the connective tissues of animals, such as skin and connective tissues. In the past, our ancestors ate ALL the parts of an animal. They would make bone broth from these “leftover” parts and even make “strange” recipes like head cheese.

Nowadays, most of us eat only the muscular flesh of animals. Muscle meats are a great source of many nutrients, such as iron and other amino acids such as methionine.

However, they lack glycine. This results in a severe imbalance of the amino acids and, in turn, can lead to inflammation. If you are only eating muscle meats, you will end up with an imbalance, but you will also lose the benefits of glycine.

Final Thoughts About Glycine

Glycine is a conditional/non-essential amino acid found in the broth of bones, meat, poultry, eggs, dairy products, and sure beans and vegetables.

It helps form collagen and gelatin, essential substances for constructing connective tissue throughout the body.

Glycine is beneficial in food and supplements for people with joint pain, digestive disorders (such as IBS, IBD, or sensitive foods), fatigue, trouble sleeping, anxiety, and low immunity.

A daily amount of glycine or an upper limit is not recommended, and studies have shown that it can be safely used in high doses of up to 15-60 grams a day when needed.

However, estimates show that most people who consume a standard western diet consume only about two grams of glycine from their daily diets, most likely because concentrated sources, such as tendons, skins, and animal bones, are often thrown away.