Types of Amino Acids: The 20 Your Body Uses

Patients often ask me for a simple guide to the types of amino acids they can keep on the fridge. It is a smart request. Amino acids function as the building blocks of every protein in your body. So when you know what they are, you can make better choices about food and supplements.

In this post, I will share all 20 types of amino acids and explain the three main groups. I will also cover food sources and when a protein supplement makes sense. You can explore our full amino acid and protein supplement collection to see the options we offer.

What Are Amino Acids?

Amino acids are small molecules that link together in chains. Then those chains fold into proteins. Your body uses proteins to build muscle, skin, hair, enzymes and hormones. In fact, almost every process in your body depends on protein.

Your body also uses 20 standard amino acids to build proteins. The order of these amino acids decides what each protein becomes. Think of them like letters. Just as 26 letters form every word, 20 amino acids form every protein.

How Amino Acids Function Beyond Protein

Amino acids do far more than build muscle. A 2009 review in the journal Amino Acids explains that they also act as signals inside cells [1]. For example, they help control which genes turn on and off. They also serve as raw materials for hormones and other key compounds [1].

The review lists several of these compounds. Examples include nitric oxide, glutathione, taurine, serotonin and thyroid hormones [1]. So when amino acids function well, they support far more than your muscles.

All 20 Types of Amino Acids

Here are all the types of amino acids your body uses to make protein. I have grouped them the way doctors and dietitians usually do. That is, the groups depend on whether your body can make each one.

Essential Amino Acids

Your body cannot make these nine amino acids. As a result, you must get them from food every day.

1. Histidine.
2. Isoleucine.
3. Leucine.
4. Lysine.
5. Methionine.
6. Phenylalanine.
7. Threonine.
8. Tryptophan.
9. Valine.

Nonessential Amino Acids

Your body can make these from other nutrients. You still get them from food. But you do not depend on food alone, since your liver can build them.

1. Alanine.
2. Asparagine.
3. Aspartic acid.
4. Glutamic acid.
5. Serine.

Conditionally Essential Amino Acids

Your body usually makes enough of these. However, during illness, stress, injury or rapid growth, your needs can outpace what you make. That is when food or supplements matter more.

1. Arginine.
2. Cysteine.
3. Glutamine.
4. Glycine.
5. Proline.
6. Tyrosine.

Acidic Amino Acids and Basic Amino Acids

Scientists also sort this list by electric charge. Acidic amino acids tend to carry a negative charge in the body. There are two of them: aspartic acid and glutamic acid. Basic amino acids tend to carry a positive charge. These are lysine, arginine and histidine. That charge helps shape how each protein folds and does its job.

You may notice that this chart of the types of amino acids uses short names. On supplement labels, you will often see an "L-" in front, as in L-glutamine or L-tyrosine. That simply names the natural form your body uses. For example, our GreenMed Rx greens powder lists L-glutamine on its label.

That makes 20 in total. Some lists also add selenocysteine, a rare amino acid found in a few special proteins. Still, the 20 above make up the standard types of amino acids most people learn.

What Each Group of Amino Acids Does

Knowing the types of amino acids helps more when you know each job. Here are some of the jobs I explain most often.

Essential Amino Acids for Muscle

Leucine, isoleucine and valine are called branched-chain amino acids, or BCAAs. So they play a big role in muscle. Leucine, in particular, helps signal your body to build new muscle protein. That is why it gets so much attention from athletes.

Mood, Sleep and Focus

Tryptophan is the raw material for serotonin, a brain messenger tied to mood. Your body also uses serotonin to make melatonin, the sleep hormone. Meanwhile, tyrosine is used to make dopamine and thyroid hormones. Phenylalanine can turn into tyrosine in the body.

Gut, Immune and Antioxidant Support

Glutamine is a main fuel for the cells that line your gut. It also supports normal immune function. In addition, cysteine, glycine and glutamic acid, one of the acidic amino acids, join to form glutathione. Glutathione is one of the body's main antioxidants.

Heart and Blood Flow

Arginine, one of the basic amino acids, helps your body make nitric oxide [1]. Nitric oxide helps blood vessels relax and supports healthy blood flow. Glycine and proline, on the other hand, are key parts of collagen. As a result, collagen supports your skin, joints and blood vessels.

How Much Protein Do You Need?

Once you know the types of amino acids, the next question is how much protein to eat. The answer depends on your size, age and activity. So there is no single number for everyone.

As a starting point, many adults do well with protein at each meal. A palm-sized portion of fish, chicken, eggs or tofu is a simple guide. Also, spread your protein through the day rather than eating it all at dinner. That way your body has a steady supply of amino acids for repair.

Needs Change With Age

As we age, our muscles respond less to protein. Because of this, older adults may need more protein than they did when younger. Strength training also helps, since it tells your muscles to use the amino acids you eat. In my practice, I see many older adults who eat too little protein without knowing it.

Needs Change With Activity and Stress

People who exercise hard also need more protein to recover. Likewise, illness, surgery and wounds raise your needs. That is when the conditionally essential amino acids from the list above matter most. Your doctor can help you set a target that fits your situation.

Why Balance Matters

Balance is a theme I return to often with patients. Your body works best when it gets a steady, varied supply. Big swings, such as a huge dose of one amino acid, can crowd out others that share the same pathways.

More is not always better with amino acids. The 2009 review notes that excess amino acids and their byproducts can cause problems [1]. For example, the body turns extra amino acids into ammonia, which must be cleared. The review stresses that a balance of amino acids in the diet is key to whole-body health [1].

This is one reason I prefer whole proteins and balanced blends. They give you all types of amino acids in natural ratios. However, taking one amino acid in large amounts is different. That approach should be guided by your doctor.

Food Sources for All Types of Amino Acids

Food is the best source for all types of amino acids. A food that contains all nine essential amino acids is called a complete protein.

• Eggs, which are a complete protein.
• Fish, chicken, turkey and beef.
• Milk, yogurt and cheese.
• Soy foods like tofu, tempeh and edamame.
• Quinoa and buckwheat.

However, most other plant foods are low in at least one essential amino acid. Even so, you can combine them. For example, beans and rice together cover each other's gaps. Nuts, seeds, lentils and whole grains also add to your daily total.

Plant-Based Eaters and the Types of Amino Acids

Eat little or no meat? You can still cover all types of amino acids. The key is variety. So eat beans, lentils, soy, grains, nuts and seeds across the day. You do not need to combine them at every meal. Instead, aim for a good mix over the whole day. Pea protein is also a helpful option, because it is rich in lysine, which many grains lack.

Beyond the Types of Amino Acids: Helper Nutrients

Amino acids need helpers to do their work. Vitamin B6, found in chicken, fish and potatoes, helps your body break down and reshape them. Zinc, from beef, oysters and beans, supports the enzymes that build new proteins. Magnesium plays a part in protein building too, and greens and nuts are good sources. Digestive enzymes such as protease break protein into pieces you can absorb. You can browse our amino acid and protein products to see how some combine these. Then talk with your doctor about your own protein needs.

When a Protein Supplement May Help

Still, many people do not eat enough protein, especially older adults. Busy schedules, small appetites and plant-based diets can also make it hard. In those cases, a protein shake may help fill the gap.

Our Amino Restore Vanilla protein shake uses pea protein isolate and provides 28 grams of protein per two-scoop serving. Its label shows an amino acid profile with leucine, isoleucine, valine and lysine, among others. If you prefer chocolate, Amino Restore Chocolate provides 31 grams of protein per serving. Either may help support your daily protein and amino acid intake.

When you choose any protein powder, read the label first. Look at the protein source, the grams per serving and the other ingredients. Then check whether the label shares an amino acid profile. That way you can compare it with the types of amino acids above.

Before you add any protein supplement, talk with your doctor. This matters most if you have kidney or liver concerns, are pregnant or nursing, or take medication. Your doctor can help you find the right amount of protein for your body.

Keep this guide to the types of amino acids handy when you plan meals or read labels. Over time, you will start to spot the names on food packages and supplement panels. Then you can make choices with more confidence.

Knowing the types of amino acids is a great starting point. But your needs depend on your age, activity and health. At Taylor Medical Group's holistic medicine practice, we look at nutrition as part of the whole person. Visit taylormedicalgroup.net to learn more.