In search of a magic bullet that would slow down the signs and effects of aging, collagen supplementation has in recent years been being promoted in a variety of products, from skin filler to muscle-building fiber to easing arthritis symptoms.   Endorsements from celebrities add to the hype surrounding collagen.  Despite its increasing popularity, questions remain about how well it works.

What is collagen?

The body naturally makes its own collagen by breaking down dietary proteins into amino acids, which are the building blocks of the various types of protein in the body, including collagen.  Collagen is secreted by various cell, but mainly by connective tissue cells.

As the most abundant protein in the body, accounting for 30% of the total protein mass in the body, collagen has been described as the glue holding the body together, as its fiber-like structure is used to make connective tissue, connecting tissue with other tissue.  It is a major component of bone, cartilage, skin, tendons, and muscle in the body.   

Collagen plays an important part in bone health, as collagen represents more than 90% of the bone matrix.  Bone itself mainly consists of collagen fibers, reinforced with calcium phosphate, and containing specialized cells.   Collagen comprises about 60% of the cartilage that surrounds bones and cushions bones from the shock of high impact movements.   Collagen makes up about 75% of the dry weight of skin, maintaining skin structure and providing volume that keeps skin elastic and looking plumb.   Collagen accounts for 65-80% of the dry mass of tendons, while it is the major structural protein in skeletal muscle, accounting for up to 10% of muscle dry weight.    

Collagen is a hard, insoluble, and fibrous protein and there are at least 16 different types of collagens in the body (some sources quote 28).  These different types of collagens have different structures and functions., but 80-90% of them belong to types 1, 2, and 3.

Collagens are strong and flexible and in most collagens the molecules are packed together to form long, thin fibrils, which acts as supporting structures and anchor cells to each other. 

Interestingly, the fibrils from type 1 collagen are particularly able to be stretched and are, gram-for-gram, stronger than steel!

Natural sources of collagen:

Collagen is naturally found in food, mainly animal flesh, that contain connective tissue, such as meat and fish.  A variety of animal and plant foods contain materials needed for collagen production in our bodies.  During digestion in the gastro-intestinal tract (gut), collagen from food sources is broken down into amino acids, the building blocks to make protein in the body.  Amino acids are distributed to the areas where the body needs the most protein.  Although there is a lack of research that indicates whether eating collagen rich foods can directly benefit skin or joint health, many foods that support collagen production are usually recommended as part of a healthy eating plan.

Food high in collagen includes:

  • Cuts of meat full of connective tissue, for example tough cuts such as brisket, chuck, and pot roast.
  • The bones and skin of fresh as well as saltwater fish.
  • Bone broth made by simmering animal bones for many hours in water and a small amount of vinegar, which helps to dissolve the bones to release collagen and minerals.
  • Gelatin is a form of collagen that is produced when animal bones, cartilage, and skin are boiled for several hours.  When the liquid cools down and sets, gelatin is formed.
  • High-protein foods – such as meat, poultry, fish, eggs, dairy, soy, and legumes – are believed to promote collagen production, since they contain the amino acids glycine, proline, and hydroxyproline that are needed to make collagen.
  • The production of collagen in the body also requires nutrients such as zinc (found in shellfish, meats, nuts, seeds, legumes, and whole grains) and vitamin C (found in citrus fruit, tomatoes, berries, bell peppers, and leafy green vegetables).   Other nutrients include copper (found in shellfish, meat, and nuts) and vitamin A (found in both animal derived and plant foods).

Running short of collagen:

As we grow older, the body breaks down collagen faster than we can replace it.  We start losing an estimated 1% of collagen per year in our mid-twenties and by the age of 60 a considerable decline in the production of collagen is normal.  Women may lose as much as 30% during the first 5 years of menopause.  Apart from aging, collagen production may drop more quickly due to smoking (nicotine narrows the blood vessels in the skin, reducing the delivery of nutrients and oxygen), alcohol abuse, excess exposure to the sun, lack of sleep and exercise, a non-balanced diet, and chronically high levels of cortisol due to stress. 

While weakened joint cartilage may occur, the most visible effect of the loss of collagen is a decline in the structural integrity of the skin.

With age, collagen weakens, leading to wrinkles and cartilage problems.

The skin is the largest organ of the human body and 70% of its dry weight is comprised of the extracellular matrix, found in the dermis.  The extracellular matrix is an intricate network of macromolecules, which are molecules each containing many atoms.  Apart from collagen, the other two major components of elastic fibers are elastin, which gives elasticity to tissues, and microfibrils.

As collagen is the most abundant component of the extracellular matrix, it is the most important protein to play a role in maintaining the skin structure and enabling the various functions of the skin.  The structure of collagen is comparable to the structure of a rope, as three chains wind around each other to form a triple helix and these building blocks combine to form the extremely strong collagen fibrils.  The biomatrix of the skin starts to collapse when reduced levels of collagen result in the supporting scaffolding, made of collagen, loses its strength and stability.

The epidermis is the top layer of skin which forms a protective barrier, while the hypodermis, also known as the bottom or fatty layer, mainly contains fat cells and blood vessels.

A decline in collagen results in the skin starting to lose some of its elasticity, which refers to the skin’s ability to bounce back into shape, resulting in lines and wrinkles beginning to form.  The loss of collagen also results in the skin becoming increasingly thinner and drier.

Supplementing collagen:

Injecting collagen as a filler in facial skin has fallen out of favor in recent years, as other fillers last longer, with less allergic reactions.  Collagen containing skin care products, such as creams and lotions, often fail to reach the deeper layers of the skin and then fail to have any lasting influence on the skin aging process.  To reach the dermis where restoration of collagen may occur, oral supplementation seems the way to go.  Although certain foods contain collagen, there has been an increasing interest in taking supplements to increase collagen intake.

As collagen molecules are large and not easy to absorb, oral treatments for skin ageing have been unsuccessful due to their constituents being broken down by acid and enzymes in the gut.  Studies have indicated that peptides from hydrolyzed collagen can get absorbed during the digestive process in the small intestine and then delivered to skin and joints through the blood stream, where they can remain for up to 14 days.   Hydrolyzation refers to a manufacturing process in which collagen is broken down into smaller molecules called peptides, which are easier for the body to digest and absorb into the bloodstream.     

There are five types of collagens commonly used in commercially available supplements, namely types 1, 2, 3, 5, and 10.  Most supplements will contain at least one or more of these types of collagens.    

  • Type 1 is the most common and abundant type present in the human body, as it is found in all connective tissue.  Supplements may help to support healthy skin, hair, and nails.
  • Type 2 is found in the body in joints and intervertebral discs, which are the cushions acting as shock absorbers in the spine.  Supplements may help to promote joint health.
  • Type 3 is the main component of reticular fibers found in the skin and blood vessels, secreted by reticular cells.  Reticular fibers are composed of very thin and delicately woven strands of type 3 collagen.  Supplements may promote skin health by improving elasticity.
  • Type 4 is a component of the kidneys, inner ear, and eye lens.
  • Type 5 is found naturally in the cornea.  Some studies have shown promising results for potential benefits to eye health, cell membranes, and promoting placenta growth in pregnant women.
  • Type 10 is responsible for bone formation and occurs in joint cartilage.  There is currently no direct evidence, due to lack of studies, which indicates that type 10 supplements may help to directly heal an injured area or promote bone health and development.

Collagen types vary according to animal source: 

  • Bovine collagen (mainly derived from cows) contains types1 and 3.
  • Marine collagen contains type 1 and 2.
  • Chicken collagen contains type 2, which also includes eggshell membrane collagen, which contains types 1 and 5.

How effective are collagen supplements?

According to Harvard Medical School, most research on collagen supplements is related to skin and joint health.  While human studies are lacking, some trials have found that collagen supplements can improve skin elasticity, while others have found that supplements can improve joint mobility and decrease joint pain.

However, Harvard warns that most if not all the research on collagen supplements are funded or partly funded by related industries, leading to potential conflict of interest.  In some instances, one or more of the authors of the study have ties to these industries, which have a commercial interest in the positive findings of these studies.  This detracts from determining how effective collagen supplements really are.  It is not always clear exactly what collagen supplements contain and whether the supplements will do what the label and promotional material claims.  Fortunately, studies have not shown negative side effects from taking the collagen supplements.

A case in point is one of the larger studies, being a clinical interventional study on 72 healthy women on behalf of a supplement manufacturer, demonstrated that drinkable collagen peptides together with other dermo-nutrients could result in long lasting visible improvements to the skin’s appearance.  The study used a supplement containing bovine collagen peptides, which are fairly similar to human collagen, mixed in drinkable form with vitamin C, zinc, biotin, and a vitamin E complex.  Over a three-month period, improvements were seen in skin hydration, elasticity, density, and roughness.

Another study showed that a specific oral nutritional supplement, containing hydrolyzed collagen, hyaluronic acid, essential vitamins, and essential minerals, resulted in a noticeable improvement in wrinkle depth, elasticity, and hydration.

Other studies, with smaller groups of women, have yielded similar results.  From the available research it seems as if collagen supplements only show a visible effect on skin quality over a longer period, in most cases eight weeks or longer.

Another study showed that a specific oral nutritional supplement, containing hydrolyzed collagen, hyaluronic acid, essential vitamins (vitamin C and E), and essential minerals, has resulted in a noticeable improvement in wrinkle depth, elasticity, and hydration.

A word of caution when looking at results of most of these studies – they are product-specific trials and findings should not be generalized.  The concentration and type of collagen, as well as other skin-related nutrients included in the contents, would differ between products.

A few small studies have indicated that collagen supplements may help with arthritis pain and related joint pain.  However, a large, long-term clinical trial could not be found and has probably not been done yet in this regard.  Some evidence shows that taking collagen supplements may help prevent the deterioration of bone density and strength, although long-term clinical trials in this regard are also lacking.


Currently, non-industry funded research on collagen supplements is lacking, says Harvard.

A wide variety of collagen supplements are available in the marketplace.  If collagen is not produced in a way that allows the body to break it down properly, the body may be unable to use it.  The labels on products should indicate the type of collagen, the source, and other contents. 

Before taking any supplements, it is important to know that the body naturally has its own stores of collagen and can obtain more from a healthy diet.  While studies may indicate direct benefits of collagen supplements, and supplements may claim advertised outcomes, it is important to note that the body will use amino acids as it sees fit.  Supplements are not magic bullets that could replace the benefits of healthy eating and lifestyle habits, while avoiding smoking and excess sun exposure.    


Collagen.  Published online.  The Nutrition Source.  Harvard T. H.  Chan School of Public Health.   Harvard Medical School.  (

A collagen supplement improves skin hydration, elasticity, roughness, and density:  results of a randomized, placebo-controlled, blind study.  17 October 2019.  Nutrients 2019 Oct; 11(10): 2494.  Pubmed Central.  National Centre for Biotechnology Information.  US National Library for Medicine. National Institutes of Health.  USA.  (

 Effects of hydrolyzed collagen supplementation on skin aging: a systematic review and meta-analysis.  Published online 20 March 2021.  International Journal of Dermatology. 2021 Dec; 60 (12) 1449 – 1461.  Pubmed Central.  National Centre for Biotechnology Information.  US National Library for Medicine. National Institutes of Health.  USA.  (

Oral intake of low-molecular weight collagen peptide improves hydration, elasticity, and wrinkling in human skin: a randomized, double-blind, placebo-controlled study.  Published 26 June 2018.  Nutrients. 2018 Jun 26; 10(7): 826.  Pubmed Central.  National Centre for Biotechnology Information.  US National Library for Medicine. National Institutes of Health.  USA.  (

Collagen: ‘Fountain of youth’ or edible hoax?  Reviewed 12 December 2019.  WebMd.  (

What to know about collagen supplements.  Reviewed 1 June 2019.  MedicalNewsToday.  (

Effects of a nutritional supplement containing collagen peptides on skin elasticity, hydration, and wrinkles.  Published online 5 December 2015.  Journal of Medical Nutrition & Nutraceuticals.  (

What is collagen, and why do people use it.  Reviewed 16 June 2017.  MedicalNewsToday.  (

Top 6 benefits of taking collagen supplements.  Updated 21 December 2021.  Healthline.  (

Types of collagen.  Updated 6 April 2022.  Drugwatch.  (


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