Does Vegetarian Collagen Exist?

I’ll start with the bad news: There are no vegetarian collagen sources. Every collagen supplement you see on the shelf came from a living organism. Though somewhere down the line someone will probably grow legitimate collagen in a lab setting, it’s not available today or for the foreseeable future.

Now, some good news: Vegans and vegetarians probably need less dietary collagen than the average meat eater or Primal eater because a major reason omnivores need collagen is to balance out all the muscle meat we eat. When we metabolize methionine, an amino acid found abundantly in muscle meat, we burn through glycine, an amino acid found abundantly in collagen. If you’re not eating muscle meat, you don’t need as much glycine to balance out your diet, but it’s still a dietary necessity.

Collagen isn’t just about “balancing out meat intake.” It’s the best source of a conditionally essential amino acid known as glycine. The human body requires at least 16 grams per day for basic metabolic processes, yet we can only make 3 grams, and the typical omnivorous diet provides just 2-3 grams per day, so we’re looking at an average daily deficit of 10 grams that we need to make up for through diet. And in disease states that disrupt glycine synthesis, like rheumatoid arthritis, or on plant-based diets that provide little to no dietary glycine, we need even more.

What About Marine Collagen?

Okay, but eating a product made from a cuddly cow or an intelligent pig is off limits for most vegetarians. What about marine collagen—collagen derived from fish bones, scales, and skin?

Back about twenty years ago, “vegetarians” often ate fish. A number of them still exist out in the wild, people who for one reason or another avoid eating land animals (including birds) but do regularly consume marine animals. If it jibes with your ethics, marine collagen is a legitimate source of collagen for vegetarians. The constituent amino acids are nearly identical to the amino acids of mammalian collagen with very similar proportions and properties.

It’s highly bioavailable, with the collagen peptides often showing up intact in the body and ready to work their magic—just like bovine or porcine collagen. In fact, if you ask many marine collagen purveyors, it’s even more bioavailable than mammalian collagen owing to its lower molecular weight.

I’m not sure that’s actually accurate, though.

According to some sources, marine collagen comes in smaller particles and is thus more bioavailable than mammalian collagen, but I haven’t seen solid evidence.

There’s this paper, which mentions increased bioavailability in a bullet point off-hand, almost as an assumption or common knowledge.

This analysis found low molecular weights in collagen derived from fish waste. Mammalian collagen generally has higher molecular weights, so that appears to be correct.

However, a very recent pro-marine collagen paper that makes a strong case for the use of marine collagen in wound repair, oral supplementation, and other medical applications does not mention increased bioavailability. It may be slightly more bioavailable—the lower the molecular weight, the more true that is—but I don’t think the effect is very meaningful. Mammalian collagen is plenty bioavailable (most efficacious studies use collagen from cows or pigs), even if it’s a few dozen kilodaltons heavier.

But even if marine collagen isn’t particularly superior to mammal collagen, it is equally beneficial.

For skin health: Fish collagen improves hydration, elasticity, and wrinkling in humans who eat it. And again.

For metabolism: Fish collagen improves glucose and lipid metabolism in type 2 diabetics. HDL and insulin sensitivity go up, triglycerides and LDL go down.

And although fish collagen hasn’t been studied in the treatment of joint pain, if it’s anything like other types of collagen, it will help there too.

What Are Strict Vegetarian Options?

What if you absolutely won’t eat collagen from marine sources? Is there anything you can do as a vegetarian to make up for it?

Make Your Own

You could cobble together your own facsimile of collagen by making an amino acid mixture. Glycine, proline, and arginine don’t cover all the amino acids present in collagen, but they’re widely available and hit the major ones.

Still, eating the amino acids that make up collagen separately doesn’t have the same effect on those collagenous tissues as eating them together in a collagenous matrix. One reason is that the collagen matrix can survive digestion more or less intact, giving it different biological properties and effects.

In one study, rats with osteoporosis ate collagen hydrolysate that scientists had marked with a radioactive signature to allow them to track its course through the body. It survived the digestive tract intact, made it into the blood, and accumulate in the kidneys. By day 14, the rats’ thigh bones had gotten stronger and denser with more organic matter and less water content.

Another study found similar results, this time for cartilage of the knee. Mice who ate radioactive collagen hydrolysate showed increased radioactivity in the knee joint.

In both cases, the collagen remained more or less intact. A blend of the isolated amino acids would not. The fact is that collagen is more than glycine. When you feed people collagen derived from pork skin, chicken feet, and cartilage, many different collagenous peptides appear in the blood. You don’t get any of those from isolated glycine.

That’s not to say it’s pointless. Pure glycine can be a helpful supplement, used in several studies to improve multiple markers of sleep quality. Just don’t expect it to have the same effect as full-blown collagen.

Get Adequate Vitamin C

Acute scurvy, caused by absolute vitamin C deficiency, triggers the dissolution of your connective tissue throughout the body. Teeth fall out, no longer held in by gums. Wounds don’t heal, your body unable to lay down new collagen.

Vegetarians usually don’t have any issues getting adequate vitamin C.

Get Adequate Copper

Copper is a necessary cofactor in the production of collagen. Studies show that you can control the production of collagen simply by providing or withholding copper.

The best vegetarian source of copper is probably dark chocolate, the darker and more bitter the better.

Get Adequate Lysine

Lysine is another amino acid that’s necessary for the production of collagen.

The best sources of lysine are in meat of all kinds, but vegetarian options include hard cheeses like parmesan and pecorino romano, as well as eggs.

True vegetarian collagen doesn’t exist. Strict vegetarians will balk. But if you can bend the rules a bit, realize that making marine collagen out of fins and scales and bones is far less wasteful than just throwing it away, and look at the benefits with an objective eye, you’ll be pleasantly surprised. Even if you don’t end up using marine collagen, at least you have a few tools for getting many of the benefits with quick shortcuts and optimizing your own production of collagen.

Have you ever tried marine collagen? If you’re a vegetarian, would you consider it?

Thanks for reading, everyone. Take care and be well.

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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34 thoughts on “Does Vegetarian Collagen Exist?”

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  1. I have tried bone broth from all meat sources except fish, as well as many different collagen supplements (gras-fed/pastured). I always develop mouth ulcers. I’ve read it could be from the balance of high arginine to lysine, so I take lysine 500 mg twice a day, and still frequently get mouth ulcers, often when I don’t even consume collagen, but always when I do consume it. Do you think fish collagen would have a different result? Or do you have an other suggestions? Thanks!

    1. I too have those symptoms and use lysine to combat them. When it seems I’m losing the battle is usually a time when I have consumed something I may be allergic to. My theory is that the sores are a ‘ripple’ effect of how my entire digestive tract is doing.

    2. i have found that eating high lysine *foods* do much better in preventing sores. the highest are concentrated dairy products, if you eat those, like : yoghurt, esp Greek :), and cheeses. best results for me are yoghurts.

    3. Have you looked into free glutamate intolerance? I have found that I can’t tolerate bone broths, collagen supplements, gelatin, protein powders, etc. I get mouth ulcers, burning mouth and nerve pain in my teeth (along with fatigue, insomnia and other symptoms) after consuming any of these once a day for more than 2 days.

  2. I haven’t eaten red meat or pork since I was 8 years old. I do eat a little chicken, bivalves, crustaceans, some fish. We make bone broth from cooking whole chickens for many hours. I take Lysine a few times a week to combat the low detectable presence of the Epstein Barr virus from having mono when I was 19. I would absolutely consider taking marine collagen, in fact, I will probably look for it as I didn’t realize there was such a source of supplementation! Love reading your articles, so much insight, knowledge, and I always walk away that much more informed. Have a great day!

  3. If I am not mistaken, and I did recently look this up, Stuart PHillilps has never taken a position in support of collagen supplements. IN fact, he has called it everything from “rubbish” to “limited” use. Perhaps Mark can look into this with his discriminating eye.

    1. I’m a big fan of Stu Phillips and did see this – however this is different to what Keith Baar (I believe?) has found with his research on collagen and athletes from AIS – I believe he’s researched in laboratory models and human trials too.

  4. Fish stocks can be marvelously gelatinous, and I think many vegetarian friends of mine (even my lacto-ovo-pescatarian buddy!) forget how important collagen is to their bodies. I will ask them if they have ever made a homemade fish stock, and tell them how if they need the instruction…
    This is a good reminder! To ease the minds of some conscientious vegetarians, the materials used for the manufacture of collagen supplements are merely byproducts that would otherwise be wasted.

  5. dear Mark,
    i was wondering: on fish gelatin, is there any advantage or disadvantage to that made with fish *scales* vs fish *skin*? thanks

    1. Hi Fiona. I might have missed a link but what looks yummy and where’s the recipe?

  6. As a veggie/pescatarian myself, with a strictly veggie husband, I really appreciate your looking into these issues for us, Mark. You manage to do it in a way which feels discerning and without an agenda to get those of us who don’t feel good about it, to eat meat. Unbiased information so we can make individual assessments about what works for us, whilst supporting our ethics is invaluable.

    1. Helen, I’m glad you enjoyed the article. I have family members who are vegetarians, and I think it’s important for anyone to have the facts they need to make the best choices for their health. Best — M

  7. Yes there is and way better then in meat you get to make all kinds of dishes with it to it’s a thickener called Irish moss glorious seafood

  8. re the amount of glycine we need… the study in the link seems to say that we fall short by 10g after accounting for biosynthesis and normal dietary intake. This vs 10g total need in the article. Can you clarify?

    1. I should add that the study considers 1.5-3g of dietary glycine… so added to the biosynthesis part of 3g = 6g… and this amount falls short of what we need by 10g. So the study suggests we need 16g total vs the 10g as suggested in the article.

      1. Jeff, thanks for pointing this out. I wasn’t accounting for the amount the typical omnivore gets from dietary sources, which then threw the overall calculation. The paragraph is corrected now to give the full picture.
        “The human body requires at least 16 grams per day for basic metabolic processes, yet we can only make 3 grams, and the typical omnivorous diet provides just 2-3 grams per day, so we’re looking at an average daily deficit of 10 grams that we need to make up for through diet. And in disease states that disrupt glycine synthesis, like rheumatoid arthritis, or on plant-based diets that provide little to no dietary glycine, we need even more.” 

  9. If I eat a tin of sardines three or four times per week, will that provide enough collagen assuming the sardines include skin and bones?

  10. I totally disagree with the above article.We really only need fruits to be in optimum health,nothingelse! we are frugivores.Ofcourse,before embarking on a frutarian diet,you need to cleanse all the poisons (mucus) you have accumulated along through your life, this can take many years & you`d need to transition with mucusless foods,like vegetables,raw & cooked & some other (NOT SO HEALTHY)foods.You can have a look at Professor Arnold Ehret’s “Mucusless diet healing system” & other books, I am sure you will find them very interesting.Finally just want to mention that we don’t need to consume any supplements at all, if your body is clean, you will assimilate everything your body needs from ,for ex one apple,Most supplements are pure synthetic & expensive,useless crap.So please stop sending me all the bullshit,I have gone through it all & have finally found my way, I have healed myself from terrible illness without the help of any of the above ,thank you very much,please no more snake oil.Thank you

    1. I’m glad you are now healthy Cris, but your assessement of supplements is just plain wrong in my humble opinion. CoQ10 elimated or greatly mitigated my MVP. Quercitin is a godsend for addressing the sinus and respiratory problems I used to have. d-Ribose helps raise my energy levels without being a stimulant. Other supplements have helped to raise my T3 levels. I could go on, but limited space here. You do need to have some patience, it may take a few months for a supplement to start helping with a specific condition. When purchasing supplements you want to research the company and make sure they have a good quality control process in place. A supplement is just that, to “supplement” when needed a healthy diet and lifestyle. You are condeming all supplements with a broad brush stroke. And … you are advocating eating an all fruit diet? I would think that could cause some blood sugar / insulin resistence problems.

  11. As someone with the dreaded alpha-gal allergy, I’m very glad that marine collagen products exist! I put a scoop in my coffee every morning, and I also make homemade chicken stock once a week, so I’m feeling pretty good about my collagen intake.

    (Also, not exactly primal, but kosher marshmallows are made with fish-based gelatin, hurray! Manischewitz brand toasts up just like the real thing… I tried another brand that just did not have the right texture…)

  12. Very timely, Mark. Just the question that was on my mind this past weekend during my quest to find a non-bovine source of collagen peptides due to dietary restrictions and surprisingly chanced upon marine collagen, wondering how it compares. Thanks!

  13. Well, as long as B vitamins are adequate through supplementation, Serine interconverts with Glycine when needed. Nuts are a great source of Serine.

  14. I started taking Lysine and Tryptophan and the two really help sleep, I sleep deeper and regain energy faster. I’m also able to dream more vividly and remember it after waking up.

    I’ve significantly reduced lean meat consumption down to 50% or probably less. I lean more toward gizzard, heart, and sometimes other organs.

  15. I’ve been taking a vegan collagen builder for months now (not sure why this article claims that none exist) and am very happy with the results. My hair, skin, and nails are radically different from prior to using the products. I use mykind Organics Plant Collagen Builder by Garden of Life. I’ve a big proponent of using whole foods for health issues, and only using whole-food organic supplements.

    Being someone who helps people successfully heal from chronic disease naturally, I agree with much of what Cris says. It’s very easy to take supplements to solve health problems without getting to the root cause of what cause the problem to begin with. The supplement fixed the problem…. what problem? The supplement industry is out of control, and many people try to use it as a quick fix, sometimes causing other issues and deficiencies as a result of taking too much of a type of supplement.

    Not to mention most supplements are synthetic counterparts of whole foods, most of which are manufactured in China.

  16. Mark, I have been following your blog for over a year now I am so grateful for the information you share and the comments people leave behind. Your newsletters are what inspired me to start my own blog on health, fitness and nutrition since a few months now and I love your writing style. Thank you ?

  17. Thanks so much. I’m a vegetarian and wouldn’t consider using fish products, in answer to your question. I may try some of your other ideas, though. I’m losing a lot of weight and my skin is starting to sag!