What Amino Acids are in Collagen? Is the profile unique?


February 24, 2023


Medically Reviewed ✓


For accuracy by Dr. Cate, M.D., a board-certified family physician, biochemist, and NY Times Bestseller.

Dr. Cate's Takeaway

The combo of amino acids in collagen are found nowhere else in the edible world.

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Quick Summary

Collagen contains amino acids because collagen is protein — and amino acids are the building blocks of protein. There are 19 total amino acids in collagen (8 of which are essential): Alanine, Arginine, Asparagine, Aspartate, Cysteine, Glutamate, Glutamine, Glycine, Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Proline, Serine, Threonine, Tyrosine, and Valine. Collagen is missing the essential amino acid, tryptophan. 50% of the 19 amino acids in collagen are heavily concentrated in Glycine, Proline, and Hydroxyproline (modified amino acid). The magic behind collagen to repair our connective tissue is the bioactive peptide when these 3 amino acids are combined and form a triple-helix structure. This combo of amino acids is only found in collagen and the reason why collagen protein is unique and powerful.

Let’s start with getting a basic understanding of amino acids — the building blocks of protein.

Amino Acids 101

There are 300+ different amino acids known to science. 20 are used by the human body.

These 20 amino acids are used in every cell to build the proteins you need to survive. I love how Piedmont Health summarizes this:

Protein is comprised of 20 amino acids; 11 of these amino acids are produced by the human body. For good health, we must get the other nine amino acids (called “essential amino acids”) from the foods we eat. When a food contains all nine of these amino acids, it is called a “complete protein.”

20 Common Amino Acids
Image credit: CompoundChem.com

There are 3 categories of amino acids

  1. Essential. Get from food.
  2. Non-Essential. Produced by the body.
  3. Conditionally-Essential. Non-essential that become essential in times of illness and stress.

You do not need to eat essential and nonessential amino acids at every meal, but getting a balance of them over the whole day is important. Let’s touch on each of these categories, which will help us better understand the amino acid profile of collagen.

What are the Essential Amino Acids?

There are 9 essential amino acids we need to get from food (alpha listed):

  1. Histidine
  2. Isoleucine
  3. Leucine
  4. Lysine
  5. Methionine
  6. Phenylalanine
  7. Threonine
  8. Tryptophan (important to remember in the collagen conversation)
  9. Valine

Again, our bodies do not make these essential amino acids listed above — we must get them from food such as beef, poultry, fish, eggs, dairy, soy, quinoa, and buckwheat. Nom, nom, nom.

What are the Non-Essential Amino Acids?

There are 11 non-essential amino acids produced by the body (alpha listed):

  1. Alanine
  2. Arginine
  3. Asparagine
  4. Aspartate
  5. Cysteine
  6. Glutamate
  7. Glutamine
  8. Glycine (important role in collagen’s magic)
  9. Proline (also important to collagen!)
  10. Serine
  11. Tyrosine

What are the Conditionally-Essential Amino Acids?

Several of the non-essential amino acids above are considered conditional, meaning they become essential in times of illness, stress, trauma, etc. Here’s an alpha listing of the conditionally-essential amino acids:

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

Does Collagen have Amino Acids?

Does collagen have amino acids? Of course!

Collagen is protein, and amino acids (as we just learned above) are the building blocks of protein. Collagen contains 19 amino acids, including 8 essential amino acids.

Collagen is amino acids -- the building blocks of protein
Collagen protein = amino acids

Which Amino Acids are in Collagen?

Here’s a full listing of the 19 amino acids in collagen protein.

* = essential

  1. Alanine
  2. Arginine
  3. Asparagine
  4. Aspartate
  5. Cysteine
  6. Glutamate
  7. Glutamine
  8. Glycine
  9. Histidine*
  10. Isoleucine*
  11. Leucine*
  12. Lysine*
  13. Methionine*
  14. Phenylalanine*
  15. Proline
  16. Serine
  17. Threonine*
  18. Tyrosine
  19. Valine*

You probably noticed I listed 19 amino acids above — not 20. So, which amino acid is missing?


Collagen is missing tryptophan and thus not considered a complete protein. However, that doesn’t mean collagen isn’t critical. Its amino acid profile is unique and not found anywhere else in the world! More on these special properties below after we learn more about collagen’s amino acids.

What role does Collagen’s Amino Acids play in the body?

Here’s a quick breakdown of each amino acid in collagen, and its role in the human body.

Amino Acid
* = essential
Alanine Involved in sugar and acid metabolism, provides energy for muscle tissue, brain, and central nervous system.
Arginine Cell division, wound healing, immune function, release of hormones.
Asparagine Breaks down toxic ammonia within cells, important for protein modification.
Aspartate Helps every cell in the body work. Plays a role in hormone production and release.
Cysteine The main amino acid in keratin, which is the major protein that nails, hair, and the epidermal layer of the skin are made of. It’s also vitally important for making collagen that supports the deeper layers of skin and many other body structures.
Glutamate Most abundant neurotransmitter in your brain and central nervous system. Helps shape learning and memory.
Glutamine Glutamine is the most abundant and versatile amino acid in the body, critical to metabolism.
Glycine Contributes to cellular growth and health, needed for the growth and maintenance of tissue and for making important substances, such as hormones and enzymes.
Histidine* Required for synthesis of proteins. Many sources suggest it's the most active and versatile amino acid.
Isoleucine* One of the three BCAAs (Branched Chain Amino Acids), heavily concentrated in muscle tissue.
Leucine* Another BCAA critical for protein synthesis, muscle repair.
Lysine* Helps the body absorb calcium and formation of collagen and elastin.
Methionine* This amino acid is required for growth and tissue repair.
Phenylalanine* Makes chemical messengers (tyrosine, dopamine, epinephrine, and norepinephrine), but many studies are unsure how it works.
Proline Extremely important for the proper functioning of joints and tendons, repairs skin, heals gut lining.
Serine Needed for the proper metabolism of fats and fatty acids, production of antibodies.
Threonine* Plays a vital role in metabolism, macromolecular biosynthesis, and gut homeostasis.
Tyrosine Made from another amino acid, phenylalanine. Essential for production of brain neurotransmitters.
Valine* The last of the three BCAAS. Stimulates muscle growth/regeneration and involved in energy production.

Most Common Amino Acids in Collagen: The Big 3!

What are the most common amino acids in collagen?

We’ve all heard of the ‘Big 3’. If you’re an NBA fan, you’ve seen mega teams assembled with three all-star players. Since I grew up near Chicago, I’ll of course use the example of Jordan/Pippen/Rodman — greatest Big 3 of all time. Unstoppable, baby.

Collagen also has a ‘Big 3’ and yes, it’s also unstoppable.

The Big 3 Common Amino Acids in Collagen

If you were to break down collagen’s amino acid profile, 50% of the 19 amino acids listed above are heavily concentrated in these three:

  1. Glycine
  2. Proline
  3. Hydroxyproline

Wait, hold up. Hydroxyproline?


Hydroxyproline is a modified amino acid in collagen

The chemistry behind hydroxyproline is pretty simple. It’s hydroxy (hydrogen+oxygen) + proline. However, the definition isn’t so simple. Depending on your reference, hydroxyproline is defined a few different ways:

  • Modified amino acid (per Dr. Cate)
  • Neutral heterocyclic protein amino acid (per DrugBank)
  • Metabolite/amino acid (per NCBI). Note: a metabolite is a substance made or used when the body breaks down food, drugs or chemicals, or its own tissue.

However you describe it (we’ll stick with Dr. Cate’s definition of modified amino acid), the important thing to remember here is the magic that happens when glycine, proline, and hydroxyproline combine forces!

Why is Collagen’s Amino Acid Profile unique?

What happens when the Big 3 are combined? Magic. Not Disney-like magic, but real-life magic to rejuvenate, build, and repair our connective tissue!

Here’s what happens behind the curtain.

Hydroxyproline, combined with proline and glycine, form a bioactive peptide (a peptide is 2-3 amino acids strung together in a chain). These amino acids are incorporated into collagen fibrils, and then wind together to form the triple-helix structure we call collagen protein.

Collagen Triple Helix
Collagen’s triple helix: Hydroxyproline, Proline & Glycine

When we see this sequence of amino acids (glycine + proline + hydroxyproline), it then tells our body — as our founder Charlie says — “Go fix stuff!”

THIS is the key to collagen’s amino acids and why it’s so unique. 

This combo of amino acids are found nowhere else in the edible world!Dr. Cate, M.D.

Did you miss that? This fact is your most important takeaway in this entire article about collagen’s amino acids. This bioactive peptide is not found anywhere else in the world. It’s unique to collagen. And this bioactive peptide heals — it’s why collagen supplements’ benefits are talked about everywhere.

Don’t believe us? Check out the evidence in our reviews. This sequence of amino acids is the power of collagen.

Final Takeaway

Collagen is everywhere in your body. Connective tissue, skin, hair, nails, cartilage, bone. It’s the glue that holds us together.

Though there’s no RDA for collagen, we all need more of it. And to be precise, we all need collagen’s amino acids — triple-helix anyone?

To INCREASE your collagen, you need to EAT your collagen from foods that contain collagen. If things like bone broth and organ meats aren’t your jam — and for most people they aren’t — shop our multi collagen store and help your body start fixing stuff!

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This Collagen College™ article created by:


Eric Sharp CMO

Eric Sharp

Eric discovered collagen back in 2019 (thanks to Charlie) and been a believer since. He brings 20+ years of digital marketing experience to the CB Supplements team. As CMO, he's directly responsible for crafting the CB Supplements positioning, content, branding, and overall marketing direction.



Dr. Cate

Dr. Cate Shanahan is our Medical & Scientific Advisor. She is a Board-certified Family Physician, biochemist trained at Cornell University, and New York Times Bestseller.

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