Collagen supplements are becoming quite a hit amongst fitness enthusiasts and health-conscious people alike.

It makes one wonder what all the craze is as of late; is collagen all that it’s really cracked up to be?

  • What are the benefits of collagen?
  • And what the heck is collagen?
  • Is collagen good for those on the keto diet?

Don’t fret, this guide will take you from A to Z on all things collagen, including what collagen is, the benefits of collagen supplements, possible drawbacks, myths, and how you can choose the best collagen type for your goals.

What Is Collagen?

In short, collagen is the most abundant protein in higher life forms, making up roughly one-third of the body’s total protein content.[1]

There are over 40 known types of collagen in the human body, with three particular types being of crucial importance for skin health, joint function, and other connective tissues.

Collagen is rich in the amino acids L-lysine, L-glycine, L-alanine, and L-proline, which are necessary for proper formation of elastin and other key fibrous proteins in the body.[2] Thus, collagen is a major contributor for healthy connective tissues, especially skin.

Collagen levels naturally decrease as we age past our 20s. In fact, research shows that collagen production drops by about 25% at the age of 40; by the age of 60, it drops by upwards of 50%.[3]

Furthermore, the vast majority of us do not get sufficient collagen through our diet. As such, supplementing with a premium source of collagen peptides can be beneficial for keeping our bodies healthy and vivacious.

But what exactly are the benefits of collagen? Well, that depends on the type of collagen you consume…

Types of Collagen

As aforementioned, there are over 40 types of collagen found throughout the body. However, three main types of collagen are found in collagen supplements, including type-I collagen, type-II collagen, and type-III collagen.

Before you purchase a collagen supplement, is essential to know what body tissue you primarily want to treat.

Remember, collagen makes up many connective and soft tissues throughout the body; if you supplement with the “wrong” type of collagen, you might not notice benefits in the tissue (or health issue) you’re trying to target.

Type-I Collagen

The major form of collagen present in skin tissue (including hair, nails, etc.) Also abundant in bone, organs, and ligaments. This type of collagen is ideal for anti-aging benefits and overall skin health.

Type-II Collagen

Type-II collagen is primarily found in cartilage and joints. As such, this collagen type is best for individuals looking to improve their joint function and integrity (especially those with osteoarthritis).

Type-III Collagen

Type-III collagen is a lesser-known (albeit still important) type of collagen that makes up fibrous protein in connective tissues, such as tendon, denton, cartilage, and bone.

This is generally the best collagen type if you have weak/frail bones, teeth, and/or pain during muscular contraction.

Benefits of Type-I Collagen Supplements

Collagen peptides are great for many things, but skin health appears to be the primary reason so many people take it.

  • Reduce face wrinkles
  • Enhance skin elasticity
  • Boost skin smoothness and hydration
  • Support bones and ligaments
  • Fortify nails and hair
  • Provides high amounts of L-glycine and other amino acids

Type-I collagen is touted as the best collagen for anti-aging, especially in regards to skin. Biomedical research shows that type-I collagen can significantly enhance skin hydration and reduce roughness.[4]

Skin is your body’s largest organ, accounting for upwards of 8% of total body weight, on average.

Healthy skin tissue is crucial for protecting the network of muscles, bones, nerves, blood vessels, and everything else inside your body.

Moreover, the skin has multiple layers, each of which contains specific types of cells, such as melanocytes and keratinocytes, that require collagen to stay healthy.

Naturally, type-I collagen is the most popular type of collagen found in supplements (since many people use it for aesthetic purposes and skin enhancement).

Type-I collagen is also beneficial for hair and nails, which are modified types of skin tissue.

Type-I Collagen Enhances Skin Health

It’s arguable that the most desired benefit among people who supplement with type-I collagen is better skin health.

In the context of dermatology, skin health is comprised of elasticity, roughness, and hydration.

As we age, our skin health tends to degrade due to collagen depletion.

Intuitively, it seems that taking type-I collagen peptides will provide anti-aging benefits, especially on the skin. Sure enough, research suggests this is exactly what happens…

A recent double-blind, placebo-controlled clinical trial including 69 healthy middle-aged women revealed a variety of compelling benefits that type-I collagen peptides can have on skin health and function in just 8 weeks of use.[5]

Key findings from the study showed that:

  • Skin hydration increased by more than 90% in comparison to the placebo group
  • Skin elasticity doubled in comparison to the placebo group
  • Skin roughness improved by nearly 100% in comparison to the placebo group

Furthermore, the study showed that these benefits were heightened in females over the age of 50; in fact, some of those females had more than 140% increases in skin elasticity and skin hydration in comparison to the placebo group.

There appears to be a broad range of physiological mechanisms underpinning the benefits of type-I collagen on skin health, such as antioxidant activity, supporting anabolic actions in skin tissue, UV protection, and chemotactic properties.6  

Type-I collagen peptides are also unique in that they are taken up in the gastrointestinal tract, appearing in the blood as a small peptide and then accumulating in skin tissue for upwards of five days after ingestion.

This is a vastly different digestive fate than many other food proteins you consume.

We recommend this TeamKeto article to learn more about collagen peptides for skin.

Type-I Collagen Nourishes the Gastrointestinal Tract

A critical type-I collagen benefit is that it supplies eight of the nine essential amino acids, while also providing rich amounts of alanine, glycine and proline which carry out vital roles within the body.

Alanine, glycine and proline are all crucial for proper formation of elastin; a major protein in connective tissue that helps synthesise new skin cells and regenerate joints.

Research also suggests that elastin is part of the composition of intestinal wall tissue, making it beneficial for gut health.[7]

Moreover, research shows that glycine is readily utilized by small intestinal mucosa to synthesize glutathione, one of the most important endogenous antioxidants.[8] Consuming glycine from type-I collagen thereby protects the gut from excessive oxidative stress and inflammation.

Type-I Collagen Can Protect Against Type-2 Diabetes & Elevated Blood Lipids (Hyperlipidemia)

A contemporary 12-week clinical study including 100 type-II diabetics and 50 healthy adults showed that type-I collagen peptides can significantly benefit metabolic biomarkers, such as blood lipids, fasting insulin, and blood glucose.[9]

Key findings from the study include:

  • Type-I collagen peptides lowered fasting blood glucose and fasting blood sugar in type-2 diabetics by roughly 10%; type-2 diabetics taking a placebo exhibited nearly a 10% increase in both fasting insulin and fasting blood glucose levels.
  • Type-I collagen peptides decreased both total cholesterol and LDL (“bad”) cholesterol by nearly 15% more than placebo.
  • Type-I collagen peptides reduced both free fatty acids and total blood triglycerides by about 20% more than placebo.

Supplemental Type-I Collagen Decreases Inflammation

In the same 12-week study mentioned above, supplementing with type-I collagen peptides resulted in a significant decrease of inflammatory biomarkers, such as C-reactive protein, interleukin-6, and nitric oxide.

As such, using type-I collagen may protect your body from low-grade inflammation and excessive oxidative stress.

Benefits of Type-II Collagen Supplements

  • Comprises roughly 50-60% of the total protein in cartilage
  • Accounts for nearly 90% of the collagen found in joint cartilage
  • Demonstrated to significantly enhance joint health and reduce articular pain/swelling
  • May help treat arthritis, bursitis, and synovitis
  • Contains chondroitin, glucosamine, and hyaluronic acid

Type-II collagen is generally sought after by people who deal with chronic joint pain and inflammation, particularly those with osteoarthritis and rheumatoid arthritis.

There is a growing body of clinical evidence showing the efficacy of undenatured type-II collagen peptides for enhancing joint integrity and cartilage, as well as reducing joint pain and increasing range of motion.[10]

Other benefits of type-II collagen may include neurogenesis and enhanced immune function.

Type-II Collagen Supports Joint Health

Undoubtedly, the most pertinent benefit for using type-II collagen supplements is improving joint health and cartilage integrity.

Literature on the effects of type-II collagen in regards to joint health is vast, with many studies showing significant improvements in quality of living, joint range of motion, and reductions in joint pain after just 8-12 weeks of use.

The mechanisms by which type-II collagen supports articulations are largely by reducing inflammatory cytokines and mitigating the effects of other proinflammatory factors that accumulate in joint regions.[11,12]

In a double-blind, placebo-controlled three-month clinical trial involving 60 patients with severe rheumatoid arthritis, subjects that were fed chicken type-II collagen daily experienced significant reductions in joint swelling, tenderness, and pain.[13]

In fact, 4 of the subjects taking type-II collagen had complete remission of their arthritis.

Interestingly, the same study found that cessation of supplementation for three months was associated with returning debilitating joint symptoms; reintroducing the type-II collagen supplement after this period restored the benefits.

Type-II May Promote Neurogenesis

Preliminary data suggests that type-II collagen may enhance neurogenesis, the mechanism by which neurons proliferate.[14]

Neurogenesis is an essential biological process for maintaining healthy cognitive function and reducing the risk of neurodegenerative disease; in simpler terms: neurogenesis helps you stay “all there” as you age into your later years.

In so doing, it is thought that type-II collagen peptides can also attenuate anxiety and promote a sense of well-being.

While the nootropic aspects of type-II collagen in humans remain mostly hypothetical, it is postulated that this form of collagen works in a similar manner as other neurotrophic factors, such as NGF and BDNF.[15]

Benefits of Type-III Collagen Supplements

  • Improve skin elasticity
  • Fortify your cardiovascular system
  • Improve hair texture and growth
  • Support organ function
  • Enhance circulation
  • Provide a high amount of glycine to the body

Type-III collagen belongs to the fibrillar collagen group. Its molecular structure is similar to that of type-I collagen.

Being fibrillar collagens, type-III collagen and type-I collagen are major constituents of the interstitial matrix, which also contains elastin, hyaluronan, and proteoglycan [16].

In humans, mutations of type-III collagen are connected with vascular deficiency, fibromyalgia, aneurysms, Ehlers–Danlos syndrome, and other health complications.

In contrast to the majority of other collagens, type-III collagen consists of just one collagen α (alpha) chain. Most of the type-III collagen in your body is found in the dermis and aorta. In bones and tendons, the ratio of type-III to type-I collagen is rather low.

Research shows that type-III collagen constitutes about 10% of the total collagen components in cartilage, with the majority being type-II collagen.[17]

Within human cartilage, type-II, and type-III collagens present in single fibrils, with some of them being crosslinked.

Type-III collagen is naturally produced by fibroblasts and other mesenchymal cell types in your body, making it an important protein in various inflammation-related conditions, such as lung injury, hernia, liver diseases, kidney fibrosis, and vascular complications.

Research suggests that, for fibrosis and fibromyalgia, type-III collagen supplements are valuable.[18] Other findings show that type III collagen can promote healthy vascular function and improve circulation.[19]

What Type of Collagen Supplements Should I Use?

Ultimately, most people use collagen for its benefits on skin health and anti-aging. If those are the benefits you desire, type-I collagen is your best bet.

If you have ongoing joint pain and debilitating inflammation, a quality type-II collagen supplement is the ideal choice.

For bone health and muscle aches, like those that people with fibromyalgia often experience, type-III collagen is a suitable option.

Remember, many other types of collagen exist, although they are rarely found in dietary supplements since they appear to play much lesser roles in the body.

Sources of Collagen Supplements

Along with choosing the appropriate type of collagen you should use, you also need to consider which source of collagen is best for you.

After all, not all collagen is made equal, and choosing a proper collagen source can drastically alter the benefits you get.

See the subsections below for the major sources of supplemental collagen.

Marine (fish)

Marine collagen peptides derive entirely from fish, particularly the scales or skin.

A major advantage of marine collagen is that it is solely type-I collagen, making it ideal for those who want to improve skin health.

The discrete amino acid composition and structural makeup of marine collagen peptides also provide a myriad of research-backed therapeutic benefits.

Another advantage of marine collagen is its exceptional bioavailability; in simpler terms, your body is able to actively absorb and utilize this source of type-I collagen.

In fact, your body absorbs marine collagen 150% more efficiently than other sources of type-I collagen, making it a premium source of this particular collagen.

Marine collagen has the most tightly packed particle size and lowest molecular weight of all collagen types.

This enables marine collagen peptides to pass through the digestive tract and into your blood quickly, thereby enhancing recovery and repair of various tissues, as well as providing vital amino acids to your body.

Marine Collagen Pros & Cons

  • PROS: Collagen peptides from marine sources are touted as being superior for raising overall body collagen (especially type-I) and significantly enhancing skin, hair, nails and to a lesser degree, bone health.
  • CONS: Marine collagen is typically the priciest collagen source. It also can be tough to find in certain regions.

Fowl (Chicken)

The sternum of chicken is a premium source of undenatured type-II collagen, often found in joint supplements as the patented ingredient UC-II®. UC-II® is glycosylated and appears to be exceptionally bioavailable and safe.[20]

Denaturation of a protein is an irreversible process that unwinds peptide chains and breaks them into their amino acid constituents.

Denaturing a protein typically happens at high temperatures, and is one of the processes for making gelatin protein supplements.

In the case of collagen, like UC-II®, denaturing to completion will more or less inactivate the benefits it may have on joint health and cartilage integrity.

The 3D structure and conformation of peptides like collagen give it unique bioactive properties; if that structure is lost by denaturation, you are left with merely amino acids.

Be careful to note that you may find hydrolyzed collagen supplements, which are not the same as undenatured collagen peptides like UC-II®.

Hydrolysis of collagen breaks the peptides down into smaller peptide chains that are still in the molecular weight range of bioactive collagen peptides, but you need a much larger dose to see noticeable benefits.

As such, your best bet is finding pure, undenatured collagen peptides of the specific type you’re using.

Fowl Collagen Pros & Cons

  • PROS: Chicken collagen peptides are documented as being the most efficacious source of collagen for enhancing cartilage integrity. As such, type-II collagen peptides are typically derived from chicken sternums.
  • CONS: Chicken collagen is not effective for increasing overall body collagen, nor is it ideal if your goal is skin/beauty benefits.

Bovine (Beef/Cow)

Bovine collagen, also known as beef collagen, is rich in both type-I and type-III collagen peptides, making it ideal for those looking to improve bones, ligaments, tendons, skin, eye function, and cardiovascular health.

In general, bovine collagen is extracted from cow hides and comes as either a gelatin or hydrolyzed form of collagen.

A contemporary study that used collagen peptides from bovine bones showed that chronically aged skin had significant improvements in laxity and texture after just 8 weeks.[21]

Bovine Collagen Pros & Cons

  • PROS: Bovine/beef collagen peptides are generally the most affordable collagen supplements, and are widely available due to the abundance of bovine sources.
  • CONS: Bovine collagen doesn’t appear as potent as marine collagen for increasing overall body collagen, particularly type-I collagen. Will not benefit joint health as much as chicken collagen.

Porcine (Pig)

Like bovine collagen, porcine (pig) collagen, also called pork collagen, is high in type-I and type-III collagens.

It is typically found in beauty products and marketed as an effective anti-aging, skin-fortifying supplement.

Porcine Collagen Pros & Cons

  • PROS: Similar to bovine collagen peptides, pig collagen supplements are cheaper cost and make up a large proportion of the collagen supplements that are currently available due to the abundance of porcine materials.
  • CONS: Inferior to marine collagen peptides for increasing overall body collagen levels, especially type-I collagen. Not efficacious for enhancing joint health.

Collagen Supporting Nutrients

Vitamin C

Vitamin C (ascorbic acid) is critical for collagen synthesis. Research shows that vitamin C is an integral component in the maintenance of mature collagen matrices in humans and preventing the skin condition scurvy.[22]

Hyaluronic Acid

Hyaluronic acid is a worthwhile adjunct to type-I collagen if your main goal is to enhance your skin health and function.

In a double-blind, placebo-controlled 4-week study, subjects who took hyaluronic acid experienced significant decreases in skin dryness and wrinkles, as well as improvements in skin hydration.[23]

There is also evidence that collagen synthesis is stimulated by hyaluronic acid, particularly in skin damaged by ultraviolet light.[24]

Ingredients to Avoid When Picking a Collagen Supplement

If you’re on the keto diet, be wary of collagen supplements with carb fillers (like maltodextrin), added sugars, artificial flavoring, and other unnecessary additives.

Always be sure to check the nutrition label and ensure the product is low in carbs so you don’t get kicked out of ketosis.

Collagen Supplement Myths

There seems to be an ever-increasing body of myths behind collagen supplements. This section will separate the facts from fiction of collagen supplements.

Myth: Collagen supplements will make you live longer

There is no clinical or scientific evidence that taking a collagen supplement will increase your lifespan.

While collagen is undoubtedly beneficial for many health conditions and anti-aging (in the aesthetic sense), it remains to be demonstrated that using collagen supplements will add years to your life.

Moreover, very few supplements will extend your lifespan if you’re not leading an otherwise healthy lifestyle.

The main focus should always be on your diet and exercise regimen, as those have the greatest impact on your longevity.

Myth: Consuming collagen doesn’t count towards my macronutrient intake like other protein sources

Despite its unique actions in the body and amino acid composition, collagen is still a dietary source of protein just like any other food protein you eat. If you’re on the keto diet, ingesting collagen still counts toward your daily protein needs.

However, you should not be relying on collagen as your sole source of protein. Collagen has a lower amount of key muscle-building amino acids compared to proteins like whey, casein, eggs, fish, etc.

In reality, you only need a couple 100 milligrams of undenatured collagen per day (if even that) depending on the benefits you are after.

Hydrolyzed forms of collagen usually require a larger dose, generally at least 10 grams per day. In either case, that’s a fairly minimal amount of protein.

Myth: Collagen supplements will change my skin and joint health overnight

Collagen supplements take time to work their magic; don’t expect them to improve your skin and joint health after just a few doses.

Pretty much all the data covered throughout this article had subjects taking an efficacious dose of collagen peptides for at least 8 weeks (if not longer).

Just like pretty much any other dietary supplement, you need to use collagen regularly for a modest length of time to get the benefits discussed herein.

For most people, it should be considered a supplement to use indefinitely (or in a cyclical manner).

Myth: Collagen and colostrum are basically the same things

About the only similarity between collagen and colostrum is that they are both a source of protein and they have similar-sounding names.

However, colostrum is much different than collagen in terms of its biological nature and actions in the body.

Myth: Collagen is great for building muscle

Actually, collagen is not the ideal form of protein if your goal is mainly to pack on lean body mass.

Collagen has minimal L-leucine compared to other forms of protein; also, remember that collagen peptides present in the blood typically accumulate in target tissues, such as skin or cartilage.

If your goal is primarily to build muscle on the keto diet, then you’ll want to incorporate things like lean beef, chicken, whey protein powder, etc.

Myth: Hydrolyzed collagen is the best form of collagen since it’s essentially “pre-digested”

While hydrolysis of things like whey protein or casein protein can be beneficial, hydrolyzed collagen is inferior to undenatured collagen peptides. Remember, you want to consume whole, intact collagen peptides for maximal benefits, not just the constituent amino acids.

As such, your best bet is to find collagen peptides that are undenatured if possible. If you choose hydrolyzed collagen, you will need to consume a significantly larger dose to experience noticeable benefits.

Collagen Supplement Downsides

Arguably the main drawback of collagen supplements is that they need to be used continually to notice much benefit; once you stop using a collagen supplement, many of the benefits are likely to dissipate.

Therefore, don’t start using any collagen supplement if you’re hoping for a quick, one-time fix.

You will need to assess the cost-to-benefit ratio and commit to using collagen supplements indefinitely if you think it’s worth it. This concept applies to many dietary supplements, not just collagen peptides.

Another drawback of some collagen peptides is that they remain costly.

On average, you’re going to be paying anywhere between $2.00-$4.00 for an efficacious dose of marine collagen. The good thing is you only need to consume it once a day if the dose is high enough, but that’s still a considerable cost for many people.

A final collagen downside is that there is no vegan source for it.

However, if you’re on the vegan keto diet, you can still consume collagen-supporting nutrients and amino acids, like vitamin C, proline, glycine, and alanine.

Collagen Key Takeaways

  • Collagen is the most abundant protein in higher life forms. Your body’s natural production of collagen starts to drop significantly around the age of 40.
  • There are 40 known types of collagen, but type-I, type-II, and type-III collagen make up the majority of the collagen in the human body.
  • Type-I and type-III are of crucial importance for skin/connective tissue, nails, hair, bone, and overall beautification.
  • Type-II collagen is best for people with chronic joint pains/aches, including those with arthritis, synovitis, or bursitis.
  • Marine collagen is an ideal source of type-I collagen; bovine collagen is great for type-III collagen; chicken collagen is best for type-II collagen.
  • Vitamin C and hyaluronic acid are good adjunctive supplements to use with collagen peptides.
  • You must use collagen supplements indefinitely to maintain healthy collagen levels in your body; once you stop use, levels will start to drop again over time and you will likely lose the benefits.


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