Amino acids are crucial to your health. As the building blocks of proteins, they're essential to nearly every process in your body. All living things require protein to spark chemical processes. And since proteins need amino acids, they're vital to your mood, sleep, hormone balance, wound healing, muscle health, and much more.
Amino acids are molecules that build the proteins your body needs to survive and thrive.
There are 20 amino acids necessary for human wellness. Your body makes 11, but you must eat protein to obtain the other nine.
Every system in your body uses these proteins in billions of chemical reactions every second.
Most people aren't deficient in amino acids as long as their diet includes a wide variety of nutrient-dense food.
Physical and mental stress can increase your need for amino acids. If you can't eat enough in your diet, consider taking a supplement.
What are amino acids?
Amino acids are individual molecules that create vital proteins and peptides when strung together. So far, scientists have discovered over 700 amino acids, but only 20 are crucial to your body.
Of these 20 amino acids, your body can make 11 of them by reading and copying DNA instructions. You must get the other nine through your food.
These nine amino acids are, therefore, considered “essential” because the body can't make them. Instead, you get them from the protein you eat, which is most concentrated in meat, fish, eggs, and dairy.
When you eat protein, your body breaks it down into individual amino acids. Then, it uses the amino acid to build millions of new proteins, each uniquely crafted for a particular use.
Every system in your body uses these proteins in more ways than scientists understand.
Powerful benefits of amino acids
The number of proteins that amino acids make is impressive. One cell can have a thousand different proteins, each designed for a unique task.
Linked together along one or more distinct chains, amino acids form molecules like enzymes and antibodies. Some amino acids are essential to creating hormones, like testosterone and estrogen, and neurotransmitters, like dopamine and serotonin. Others help build your cells and soft tissue.
Your body uses amino acids to boost your immune system, promote energy, maintain healthy skin, support your digestive system, and keep your organs working. The list of the work amino acids perform is endless.
A 2019 study published in Biological Psychiatry reports amino acids may help diagnose and treat people with an autism spectrum disorder. In their 2021 book, The Better Brain, Dr. Bonnie Kaplan and Julia Rucklidge discuss further evidence that amino acids with ample broad-spectrum micronutrients can help improve various mental disorders and post-traumatic stress syndrome. Amino acids also help with depression, as reported by a 2020 study published in BMC Psychiatry.
Tryptophan — the amino acid you get from eating Thanksgiving turkey — is known to help you sleep and feel confident by making serotonin and melatonin. Without these two neurotransmitters, you may feel more anxious and sleep less.
Scientists also found that branched-chain amino acid (BCAA) helps you recover from intense exercise, which causes inflammation as the body recovers. Since amino acids are required to make immune system proteins — like cytokines and antibodies — they support the body's inflammatory response to exercise stress.
Researchers even think amino acids may reduce the severity of Covid-19 infections by supporting the immune system and addressing inflammation, among many other actions.
Let's take a brief look at each amino acid.
All amino acids are vital to your body's health, but we consider nine “essential” because your body can't make them. You must eat enough in your diet.
9 Amino acids
- Valine. As a branched-chain amino acid (BCAA), valine is essential for energy and muscle development.
- Leucine. Leucine is another BCAA critical to making proteins and repairing muscle, bones, and wounds. It also helps regulate sugar levels.
- Isoleucine. The third BCAA, isoleucine, is necessary for making hemoglobin and supporting your immune system. Like the other BCAAs, it sustains your muscles and energy levels.
- Phenylalanine. Your body uses this amino acid to make vital neurotransmitters like dopamine and epinephrine. It helps support a healthy nervous system and boosts memory and learning.
- Tryptophan. As mentioned earlier, tryptophan is critical in building serotonin, a neurotransmitter crucial to your sleep, mood, and appetite. It may also help treat migraines and headaches.
- Threonine. This amino acid helps form collagen and elastin, structural proteins in your skin and connective tissue. It also helps prevent fatty liver and plays a role in making antibodies.
- Methionine. As an antioxidant, methionine helps your body detoxify. It's also essential to your muscles, fat breakdown, and mineral absorption.
- Lysine. Lysine is needed to make enzymes, hormones, collagen, and elastin. It helps you absorb calcium and supports your nervous system.
- Histidine. Some medical providers have treated anemia and rheumatoid arthritis with histidine. It's vital to protect your cells and producing the neurotransmitter histamine, which is crucial to your immune system, sexual function, sleep cycles, and digestion.
You must have these so-called “nonessential” amino acids to be well, but a healthy body can make them on its own.
Some 11 amino acids your body makes are also considered “conditional.” This term means your body may not make enough when you're mentally or physically stressed. In situations like poor digestion, emotional trauma, ongoing mental stress, illness, surgery, injury, and intense sports training, dieticians often recommend high-protein diets or amino acid supplementation.
Conditional amino acids are glycine, proline, tyrosine, serine, cysteine, glutamine, and arginine.
11 Amino acids
- Glycine. Glycine helps maintain proper cell growth and produce other amino acids. It's vital for healing wounds.
- Alanine. An important energy source for muscle, alanine helps remove toxins and produce glucose and antibodies.
- Proline. Proline is critical in forming and supporting cartilage, joints, and new skin. It also strengthens heart muscles and arterial walls.
- Tyrosine. As a precursor of dopamine, norepinephrine, and adrenaline, tyrosine boosts energy, mental clarity, and concentration. It can help treat depression, too. It's also key for producing thyroid hormones and melanin — the pigment in the eyes, hair, and skin.
- Serine. Serine is another amino acid that helps maintain blood sugar levels, immune function, muscle growth, and myelin sheaths.
- Cysteine. Important for making collagen, cysteine is essential for your skin. It also helps protect against radiation, pollution, and ultraviolet light.
- Asparagine. Helps develop the nervous system and improves your stamina. It also moves nitrogen into your cells.
- Glutamine. Important to your intestinal health, glutamine provides energy to your small intestines. It also promotes a healthy brain, blood sugar levels, and muscle endurance and strength.
- Arginine. Arginine is involved in DNA synthesis and kidney detox. It helps heal wounds, makes hormones, and supports a healthy immune system.
- Aspartate. This amino acid is vital to DNA and RNA metabolism. It also helps produce other amino acids and protects the liver.
- Glutamate. Glutamate acts as a neurotransmitter and is involved in DNA synthesis and brain function.
According to the World Health Organization, this is the daily amount of essential amino acids you need to eat for every 2.2 pounds (1 kilogram) of your weight:
|Amino acid||Dose per every 2.2 lb (1 kg) of your weight|
|Phenylalanine combined with tyrosine||25 mg|
You can calculate your need by converting your weight to kilograms and multiplying it by the daily recommendation. But if that's too complicated, most people who eat a nutrient-dense, well-balanced diet eat a wide variety of protein to supply their amino acid needs.
Animal fat, like meat, eggs, fish, and dairy products, provide the most protein. But protein is also found in plant-based foods, like nuts, seeds, whole grains, legumes, quinoa, and mushrooms. Whether you're a vegetarian or a meat eater, you'll want to be sure your diet is balanced and nutritious enough to provide all the amino acids you need.
Should I take an amino acid supplement?
By eating many kinds of protein, most people aren't deficient in amino acids. However, there are reasons why you may need to take an amino acid supplement.
Ongoing mental and physical stress demands more amino acids to make the proteins needed to heal well. Poor digestion also makes some people deficient. In addition, according to Dr. Kaplan and Rucklidge of The Better Brain, there is a small percentage of people whose bodies don't use nutrients as well as others, whether they're stressed or not. These people need to ingest more nutrients than others.
Without sufficient amino acids, you may feel irritable, depressed, anxious, or tired. You could also have hormonal imbalances, slow-healing wounds, loss of pigment in your skin, eyes, or hair, a weak immune system, infertility, or an irritable gut. Also, you may not sleep well or feel interested in sex.
If you think you may have an amino acid deficiency, taking a free-form amino acid supplement could help you. Unlike a protein supplement, free-form amino acids offer single amino acids that aren't bound into proteins, allowing your body to quickly absorb and use the individual molecules.
Many other health conditions can cause symptoms like those noted above. Learning more about amino acids and seeing a health provider may help diagnose your symptoms, so you can restore your health and vigor.
- Advances in Nutrition. Nutritionally Essential Amino Acids.
- Journal of the International Society of Sports Nutrition. Amino acid supplementation and impact on immune function in the context of exercise.
- British Journal of Nutrition. Chronic treatment with a tryptophan-rich protein hydrolysate improves emotional processing, mental energy levels and reaction time in middle-aged women.