Collagen is the most abundant protein in the human body (1).

Many people take collagen supplements to support healthy skin and joints.

However… since collagen is sourced from animals, it’s not vegan.

So, are there any vegan collagen alternatives? What should vegans do to boost their natural collagen production?

This article will review what collagen is, the health benefits of collagen supplements, where collagen is sourced from, and vegan alternatives.

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What Is Collagen?

Collagen is a protein that provides structural support to connective tissues such as skin, tendons, bones, and ligaments (2).

It is synthesized mainly by fibroblasts, a type of connective tissue cell.

Within these cells, collagen precursor molecules called “procollagen” are formed. Each one is comprised of 3 amino acid chains that come together to form a triple helix shape.

These procollagen molecules are secreted into the extracellular space (the area outside of cells) where enzymes remove the ends, converting them into mature, fully functioning collagen molecules.

Then, through a process called cross-linking, certain collagen molecules pack together to form fibrils, which are strong, rope-like structures that provide support to tissues (2, 3, 4).


What Is Collagen Made Of?

Each chain in the collagen triple helix contains the following repeating sequence of amino acids: Gly-X-Y (5).

“Gly” stands for “glycine,” while X and Y can be any other amino acid. 

However, the X and Y positions of the chain are most often filled by proline or hydroxyproline (5). 

So, collagen is primarily comprised of glycine, proline, and hydroxyproline (6):

  • Glycine (Gly) is the only amino acid small enough to fit into the center of the triple helix, helping to form a strong, tight configuration (6).
  • Proline (Pro) is necessary for helix formation (5).
  • Hydroxyproline (Hyp) helps stabilize the triple helix (5).

An uncommon amino acid, hydroxylysine, is also present at the end of collagen chains and is responsible for forming cross-links with adjacent collagen molecules to create fibrils (6).


What Does Collagen Do in the Body?

In general, collagen’s role is to provide support to connective tissues. However, the precise functions vary depending on the type of collagen and its location in the body.

There are 28 different types of collagen, but types I through V are the most common in humans (2, 7).

Type I makes up 90% of the collagen in the body, providing support in bone, tendons, skin, and the sclera (whites of the eyes) (2, 8). Gram for gram, type I collagen is actually stronger than steel (6). This type of collagen is comprised of three amino acid chains: two alpha-1(I) chains and one alpha-2(I) chain, which are encoded by COL1A1 and COL1A2 genes, respectively (8, 9).

Type II is the main structural component of cartilage and is very important for joint health (10). This type of collagen is comprised of three alpha-1(II) chains, which are encoded by the COL2A1 gene (11).

Type III strengthens the skin, lungs, uterus, intestinal walls, and blood vessels. This type of collagen is comprised of three alpha-1(III) chains, which are encoded by the COL3A1 gene (12).

Type IV forms the basement membranes of cells throughout the body, often acting as a lining that surrounds organs (13, 14). This type of collagen is comprised of three amino acid chains: two alpha-1(IV) chains and 1 alpha-2(IV) chain, which are encoded by the COL4A1 and COL4A2 genes, respectively (15).

Type V reinforces tissues throughout the body, especially the cornea, and often combines with type I collagen to form fibrils (16, 17). This type of collagen is comprised of varying combinations of alpha-1(V) chains and alpha-2(V) chains, which are encoded by the COL5A1 and COL5A2 genes, respectively (18, 19).


How Is Collagen Absorbed and Metabolized?

Collagen is NOT absorbed as an intact molecule!

Like all proteins, collagen must be broken down into smaller pieces in order to be absorbed (20).

Most is absorbed in the small intestine as amino acids, dipeptides (chains containing 2 amino acids), or tripeptides (chains containing 3 amino acids) (20).

In several studies, collagen dipeptides and tripeptides were found in the bloodstream after supplementation, although levels of tripeptides were higher, indicating they might be more efficiently absorbed (20, 21, 22, 23, 24).

After absorption, some of these collagen peptides are deposited throughout the body, including in skin and cartilage tissues (22, 25, 26).


What’s the Difference Between Collagen Powder, Collagen Hydrolysate, Gelatin, and Collagen Peptides?

Gelatin and collagen peptides are similar, because they are both made from the natural collagen found in animal connective tissue, and they have identical amino acid profiles (27).

However, the structure of gelatin and collagen peptides is different, which gives them different properties (27).

Gelatin is a mixture polypeptides (longer amino acid chains) that is formed when collagen is PARTIALLY hydrolyzed (broken down) (27, 28).

  • Made by treating animal connective tissue (bones, skin, tendons, ligaments) with an acid or alkaline solution, then heating the mixture (29).
  • Harder to digest than collagen peptides, because more steps are required (30).
  • Naturally found in broths made with animal carcasses (31)
  • Creates a gel when added to warm liquids (29).
  • Can be used as a thickener in soup, broth, sauce, gravy, mousse, pudding, ice cream, yogurt, gelatin dessert (Jello-O), and gummies.
  • Can also be used in baked goods.

Collagen peptides (also called hydrolyzed collagen or collagen hydrolysate) are the short amino acid chains that are formed when collagen molecules are COMPLETELY hydrolyzed (27).

  • Made the same way as gelatin, except that enzymes are added at the end in order to further break down the collagen into peptides (27).
  • Easier to digest than gelatin, because fewer steps are required (30).
  • Will NOT create a gel when added to liquids.
  • Can be added to beverages like water, tea, coffee, juice, or smoothies.
  • Can also be used in baked goods.

What Are the Benefits of Collagen and Gelatin Supplements?

The benefits of collagen or gelatin supplements include:

1. Improves Skin Health

As we age, the collagen content in our skin decreases, causing loss of volume and elasticity, which leads to wrinkles and sagging skin (32).

Many studies have found that collagen supplements reduce signs of aging by increasing skin elasticity, hydration, and collagen density (33, 34, 35).

In 2019, a review of randomized controlled trials found that collagen peptide supplementation (doses ranging from 2.5 g/day to 10 g/day for 8 to 24 weeks) effectively promoted wound healing and decreased signs of skin aging (36).

One double-blind, placebo-controlled (DBPC) trial found that collagen peptide supplements containing a higher percentage of Pro-Hyp and Hyp-Gly led to more improvement in skin appearance (37). 

Another DBPC evaluated the effect of collagen peptide supplementation (2.5 g/day for 6 months) on cellulite in women and found a significant decrease (9%) in the degree of cellulite on the thighs compared to placebo (38).

The role of collagen in wound healing has also been examined (36, 39). A 2018 DBPC trial found that collagen peptide supplementation (10 g/day for 16 weeks) significantly improved wound healing compared to placebo (40).

Summary: Overall, there is good evidence that collagen supplementation improves skin appearance and aids wound healing.

2. Decreases Joint Pain

Osteoarthritis involves the gradual loss of articular (joint) cartilage, which is mainly composed of type II collagen (41). 

Over time, chondrocytes (cartilage cells) lose their ability to produce enough cartilage to keep up with the normal wear and tear that occurs within the joint (41). 

Eventually, there is very little cartilage left, which causes friction between bones, leading to pain and immobility (41).

Several studies evaluating the effects of collagen supplements (mainly type II) have found that they significantly improve joint pain and stiffness in patients with osteoarthritis (42, 43).

One randomized, double-blind study showed that type II collagen supplements were more effective in reducing osteoarthritis joint pain than a combination of glucosamine and chondroitin (44).

However, a 2019 meta-analysis of RCTs found improvement in stiffness but no significant differences in pain between osteoarthritis patients who received collagen supplements and those who received placebo (45).

There is also some evidence that type II collagen supplements might be beneficial for activity-related joint pain in athletes (46, 47).

Summary: Overall, the evidence is mixed, but the majority of studies support the ability of collagen to alleviate joint pain to a small degree.

3. May Protect Against Bone Loss

Type I collagen is the most abundant protein found in the extracellular matrix of bone and is important for mineralization, which determines bone strength (48, 49).

Most of the evidence linking collagen supplementation to bone health comes from in vitro studies (conducted outside of the body, like in a test tube) and rodent studies (50, 51, 52).

In humans, the research is much more limited.

One study found that postmenopausal women with osteopenia who received a supplement containing 5 grams collagen, 500 mg calcium, and 200 IU vitamin D every day for 1 year experienced reduced bone loss compared to those who received calcium and vitamin D alone (53).

In 2018, a DBPC trial found that postmenopausal women with reduced bone mineral density (BMD) who received 5 grams of collagen peptides every day for 1 year experienced a significant increase in BMD compared to the control group (54).

Summary: There are a couple of promising studies that support the role of collagen in bone health, but more research in humans is needed.

4. May Promote Hair and Nail Growth

In 2017, an open-label trial found that collagen peptide supplementation (2.5 g/day for 24 weeks) significantly increased nail growth and decreased the frequency of cracked or chipped nails; however, there was no control group (55).

In 2018, a DBPC trial found that a supplement containing collagen and other nutrients significantly improved hair growth and quality in women with self-perceived hair thinning when taken for 6 months (56).

Summary: There is a small amount of low-quality evidence that collagen supplementation promotes hair and nail growth.

5. May Increase Muscle Strength

In 2015, one DBPC trial found that collagen peptide supplementation with resistance training significantly increased muscle mass and strength in elderly men with sarcopenia (age-related muscle loss) compared with placebo (57).

Summary: Very few studies have looked at collagen’s effect on muscle strength. More research is needed.

6. May Improve Gut Health

Many health practitioners recommend gelatin supplements to improve gut integrity and balance gut bacteria.

However, very little research has evaluated these claims, and there haven’t been any studies in humans.

In 2000, a study found that gelatin supplementation protected against gastric mucosal damage in rats, but scientists weren’t sure what mechanism was responsible for this effect (58).

A study from 2003 found that patients with IBD were more likely to have lower serum collagen levels (59).

In 2017, an in vitro study found that collagen peptides improved intestinal barrier function and protected against leaky gut (60). In 2019, an animal study found that collagen peptide supplementation reduced intestinal permeability induced by major burns (61).

Gelatin tannate, which is a complex of tannic acid and gelatin, has also been used to treat acute diarrhea because of its astringent, antibacterial and anti-inflammatory properties (62, 63, 64, 65, 66).

Summary: Although collagen peptides, gelatin, and bone broth are heavily marketed for improving gut health, there is limited human evidence to back up these claims. The only exception is gelatin tannate, which has been shown to reduce acute diarrhea in children.

7. May Improve Cardiovascular Health

Collagen plays a role in heart health by providing structural support to vascular tissues and cardiac cells (67).

In 2017, an open-label trial showed that collagen peptide supplementation significantly reduced LDL-C/HDL-C ratios and improved other measures of atherosclerosis development in healthy individuals; however, there was no control group (68).

Summary: More research is needed before collagen supplements can be recommended to prevent cardiovascular disease.

8. May Improve Sleep Quality 

Glycine, the main amino acid found in collagen, also acts as a neurotransmitter and may play a role in promoting sleep by reducing core body temperature (69, 70, 71, 72).

In 2007, a randomized single-blinded placebo-controlled trial found that glycine supplementation (3 g/day) significantly increased subjective sleep quality in healthy volunteers (73).

Summary: There is limited evidence that glycine, a component of collagen, improves sleep quality.

8 Benefits of Collagen Supplements


Are There Any Vegan Collagen or Vegetarian Collagen Supplements?

Not yet!

Scientists have discovered a way to produce collagen using bacteria and yeast (especially a strain of yeast called Pichia pastoris), but supplements aren’t readily available for purchase (74, 75).

However, there are ways to support collagen synthesis in the body without actually ingesting collagen. 

You’ll see vegan supplements called “collagen boosters” or “collagen builders” that are supposed to contain nutrients that support collagen synthesis.


What Nutrients Support Collagen Synthesis in the Body?

Since there are no vegan collagen supplements currently available, the best option for vegans and vegetarians is to focus on getting adequate amounts of the nutrients needed for natural collagen production.

The following nutrients are needed for natural collagen production:

1. Amino Acids

Glycine, proline, and hydroxyproline are the main amino acids that comprise collagen (6).

Although the body is capable of synthesizing these amino acids, the amount is usually inadequate for maximal collagen production (76, 77).

To boost collagen production, it might be helpful to consume these amino acids in foods or supplements (77, 78, 79, 80).

Sources of collagen-promoting amino acids (vegan items listed in green):

  • Glycine: gelatin, pork rinds, poultry, meat, shellfish, fish, animal organs, soy, spirulina (81)
  • Proline: gelatin, pork rinds, meat, poultry, fish, soy, cheese, milk, egg white, seeds (sunflower, sesame, pumpkin), spirulina (82)
  • Hydroxyproline: chicken, pork, beef, game meat. There are no natural vegan sources of hydroxyproline, but your body can make it from proline as long as there is an adequate amount of vitamin C available. Vegan supplements are another option (83

2. Vitamin A

Topical vitamin A (retinol) increases collagen production in the skin and improves signs of aging (84, 85).

3. Vitamin C

Vitamin C acts as a cofactor for the enzymes (proline and lysine hydroxylase) that stabilize collagen’s triple helix (86).

When vitamin C availability is low, crosslinking decreases (leading to weak collagen) and overall collagen production is reduced (86, 87).

There is some evidence that supplementation with vitamin C accelerates the healing of musculoskeletal injuries, possibly due to its ability to increase type I collagen production, but most of these studies have been in rats (88, 89, 90, 91).

4. Vitamin E?

A study from 1967 found that vitamin E-deficient rats had a greater percentage of soluble collagen in their skin, which may suggest that vitamin E deficiency causes defects in the formation of collagen (92).

Other animal studies have found that vitamin E’s antioxidant properties may protect against collagen breakdown and/or boost collagen production (115, 116).

However, other studies have found that vitamin E supplementation actually INHIBITS collagen synthesis (93, 94).

More research is needed to determine vitamin E’s role in collagen production.

5. Zinc

Supplementation with zinc increases collagen production, likely because it acts as a cofactor for enzymes involved in collagen synthesis (95, 96).

There is also some evidence that zinc decreases the breakdown of collagen (97, 98, 99).

6. Copper

The availability of copper can affect collagen synthesis because copper acts as a cofactor for lysyl oxidase, an enzyme involved in collagen cross-linking (100, 101).

Copper deficiency results in connective tissue defects, especially in the heart and blood vessels (102, 103).

6 Nutrients for Collagen Production


What Are the Best Collagen Food Sources?

There aren’t too many!

Most of the articles on “collagen food sources” are actually just listing food sources of nutrients that SUPPORT collagen synthesis in addition to the few actual collagen food sources that exist.

It’s also important to recognize that collagen is not absorbed whole. 

Consumption of collagen-containing foods should be seen as a way to boost amino acids needed for the synthesis of collagen, rather than a way to directly increase collagen levels in the body.

The most common collagen-rich foods include:

1. Animal Carcasses

Collagen is found in the joints, tendons, ligaments, and bones of animal carcasses (104).

Today, these parts of the animal are typically not eaten but are disposed of or used to make broth.

2. Bone Broth?

Broth made by simmering animal bones (usually chicken or beef) for long periods of time (often 20+ hours) is called bone broth.

It is touted as a significant source of amino acids needed for collagen synthesis.

However, although bone broth is higher in protein than broth made without bones, it may not be a reliable source of these amino acids.

A 2019 study evaluated the amino acid content of homemade and commercially-prepared bone broth samples and found that they had significantly lower concentrations of amino acids needed for collagen synthesis compared to collagen supplements (105). 

The amino acid content also varies significantly depending on the type of bones and the methods used to make bone broth (105, 106).

3. Eggshell Membrane

If you’ve ever peeled a hard-boiled egg, you’ve seen a stretchy white layer that sometimes sticks to the egg.

That’s the eggshell membrane, which is actually comprised of two layers: a thick outer membrane that lines the shell and a thin, inner membrane that covers the egg white (107).

When you crack an egg while it’s raw, the membrane usually sticks to the shell.

Scientists have found small amounts of collagen (types I and V) in the eggshell membranes of chicken eggs (107).

The only way to make sure you’re consuming the membrane is to use hard-boiled eggs, and actually peel the membrane off of the shell or the egg, but it has a chewy texture and isn’t very pleasant to eat. 


What Are the Best Collagen Supplements?

Collagen supplements are generally sourced from one of the following: cattle, pigs, fish, or chicken.

There are no vegan collagen supplements currently available.

Here are some of our favorite collagen supplements.

Please note that the following links are affiliate links. As an Amazon Associate I earn from qualifying purchases.

Bovine (Cow) Collagen Products:

Porcine (Pork) Collagen Products:

Marine (Fish) Collagen Products: 

Poultry (Chicken and Egg) Collagen Products

  • Vital Proteins Bone Broth Collagen – Chicken
    • Available in powder form
    • Sourced from organic, free range chickens
    • Contains collagen types I, II, III, V & X 
  • NOW Eggshell Membrane
    • Available in capsule form
    • Contains mostly type I collagen (107)
    • Eggshell membranes are known to be a source of collagen, but it’s also difficult to know how much you’re actually getting in a supplement (107).
    • Potential option for ovo-vegetarians

Mixed Collagen Products:

  • Ancient Nutrition Multi Collagen Protein
    • Available in powder or capsule form
    • Made from 4 food sources (beef, chicken, fish and eggshell membrane)
    • Sources are non-GMO, grass fed, hormone free, cage free and cruelty free 
    • Also contains ashwagandha, calcium, and amla berry

What Dose of Collagen Should You Take?

Most studies have used doses ranging from 2.5-15 grams per day (36, 45, 53, 109).


Are There Any Potential Side Effects or Precautions with Collagen Supplementation?

Collagen supplements are generally safe, with minimal side effects (undesirable taste, upset stomach) and no evidence of toxicity (36, 110, 111). 

However, there is some concern that bone broth and collagen supplements derived from bone may contain toxic levels of lead.

In one study, chicken broth made from bones, skin, and cartilage was found to have high lead concentrations (7-9.5 mcg/liter) (112).

However, this equates to just a few micrograms per cup of broth, which is much lower than the EPA’s limit of 15 mcg/liter for lead in tap water (113, 114).


The Big Picture

Consuming collagen supplements or collagen-rich foods can be beneficial for skin and joint health.

There are currently no vegan collagen supplements available, but boosting your intake of nutrients required for natural collagen production may be helpful.

These include the amino acids glycine, proline, and hydroxyproline, vitamin A, vitamin C, vitamin E, zinc, and copper.

Research is underway to develop vegan collagen supplements, so keep an eye out for these cutting-edge products soon.

Vegan Collagen - Does It Exist? Functional Nutrition Answers

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