The Science Behind How Collagen Works

Collagen is quickly becoming the new hot supplement. But, as is the case with many natural health supplements, there is a lot of media scrutiny. It seems that every week, there’s a new article that either supports the use of collagen, or warns us that it’s totally useless. So what’s the deal? Are collagen supplements really worth the hype? Can our bodies actually absorb and assimilate oral supplemental collagen into our bodies and tissues? Or is collagen just a waste of money? Well my curious and empowered friends: read on!

So what is collagen?

Collagen is the most abundant protein found in the connective tissue in the body and is most famous for its role in skin, hair and nail health. Collagen has been elusively alluded to within the anti-aging realm of cosmetic marketing. But of course, as is the case with most marketing campaigns targeted at women and our superficial appearance insecurities, it’s not commonly explained how collagen works and how the body produces and uses it. So no, collagen isn’t just found in the skin and its main role isn’t just to make us look younger.

As a side note here, collagen is NOT a complete protein—so don’t replace your current dietary or supplemental protein with collagen. Not same/same!

 Where is collagen found?

Collagen is found in hair, skin, nails, ligaments, cartilage, tendons, bones and within blood vessel walls—all considered to be “connective tissue” in the body. Collagen accounts for roughly 90% of the dry weight making up the middle layer of skin called the dermis. The dermal layer of the skin provides the scaffolding for the tissue, which is why when the dermis is dehydrated, repeatedly overexposed to sunlight or damaged in any way, the appearance of the skin is impacted and the scaffolding becomes negatively affected in some way.

The collagen that we supplement with is found in fish and animal connective tissue, particularly in the skin, bones and scales. In traditionally made bone broth (which draws the marrow and collagen from the bones, ligaments and tendons as you boil them) and has been a popular (and nutritious) option for generations.

Is collagen effective when used topically?

Despite the rationale for its use in skincare products, collagen is too big of a molecule to pass through the epidermis (the outer most layer of skin), let alone reach its target dermal layer. This is why most “anti-aging” topical creams are made with the individual components of collagen, like glycosaminoglycans (or GAGs) and hyaluronic acid, and not collagen.

Can supplemental collagen really be absorbed and used in the body?

There has been speculation as to the efficacy of taking collagen as a supplement. Meaning, can it actually get to our skin and aid in our body’s own collagen production?

  • There have been numerous animal studies that have proven oral collagen’s ability to get into the skin and other connective tissues. A few of these studies have radio-labelled collagen peptides in order to follow them from ingestion to skin cells. These studies have shown collagen peptides to remain elevated in the skin for up to 14 days!
  • In one human clinical trial, researchers reported that the key peptides within collagen are absorbed intact from the GI tract and are delivered to target tissue such as the skin. Studies in humans have found that the peptides in collagen peak in the blood after 2 hours, but remain significantly elevated even after 4 hours. These small peptide units from oral collagen supplementation then provide the raw materials for human collagen production. The important variable to note in all human studies thus far have used hydrolyzed collagen (this means that it’s “predigested” in order to be better absorbed) in their clinical application—this allows for the greatest absorption and assimilation.
  • Once the collagen peptides have been absorbed by the body, what do they do? There have been dozens of human studies that show that collagen can increase hydration of skin and reduce the visible signs of aging, improve joint discomfort, lessen recovery time after an injury, improve physical performance, increase bone mineral density, provide cardiovascular support and even improve overall wellbeing.

Will supplementing with collagen bring about miraculous changes to your skin and body?

Using collagen as a supplement is meant to be a cog in the collective wheel of your health. Meaning, you have to ensure you are well hydrated (hydration is largely housed in that dermal scaffolding I referred to earlier). You need to exercise to allow for increased blood flow to the body and skin and for greater detoxification and stress relief. You need to eat mindfully so as to keep pro-inflammatory foods like gluten and dairy to a minimum. You need to ensure you’re getting enough phytonutrients by way of fruit and veggie consumption and by supplementing with a good quality greens product (see greens+ extra energy… you’re welcome). None of the above exist in a vacuum because the body (and the mind) don’t function this way. It’s a collective effort across all aspects of health. So while supplementing with collagen won’t be the answer to all of your woes, it will certainly be an effective piece of your health journey puzzle.

What to look for when buying collagen

Look for a collagen that is made from grass fed cow hides or wild caught cold water fish skin. For optimal absorption, look for hydrolyzed collagen (also known as collagen peptides). Look for a dose of collagen around 10 grams (most of the studies on collagen’s benefits have been in the 5-10 gram serving range). Finally, look for a collagen that mixes well and is easy to take (because compliance is key!). Genuine Health’s clean collagen ticks all these boxes for me—available in marine and bovine sources, clean collagen is highly absorbable, easily mixable, and contains 10 grams of hydrolyzed collagen per serving, and is available in unflavoured and lightly flavoured water enhancers.




Hiroki Ohara, S. I. Improvement of extracellular matrix (ECM) in the skin by oral ingestion of collagen hydrolysate Foods Food Ingredients J. Jpn.2014,  219, 216–223.

Ohara, H. et al. Collagen-derived dipeptide, proline-hydroxyproline, stimulates cell proliferation and hyaluronic acid synthesis in cultured human dermal fibroblasts. J. Dermatol 2019, 37, 330-338.

Sato K. et al. Identification of food-derived bioactive peptides in blood and other biological samples. J AOAC Int. 2008 Jul-Aug; 91(4):995-1001.

Yamamoto, S. et al. Absorption and urinary excretion of peptides after collagen tripeptide ingestion in humans Biol. Pharm. Bull. 2016,  39,  428– 434.

Yazaki M. et al. Oral Ingestion of Collagen Hydrolysate Leads to the Transportation of Highly Concentrated Gly-Pro-Hyp and Its Hydrolyzed Form of Pro-Hyp into the Bloodstream and Skin. Journal of Agricultural and Food Chemistry 2017 65 (11), 2315-2322.