What is collagen?

Collagen supplementation has been floating around social media, with influencers promoting various collagen products and supplements, but what is collagen even?

Collagen is the most common protein in the body, and is found in all kinds of connective tissue, including skin, joints, cartilage, muscles, and bones. It’s what makes these tissues stretchy and able to withstand the demands of our daily lives.

So far, 28 types of collagen have been identified in the human body, but types I, II, and III, are the most common, with type I and III most commonly found in skin.

Our bodies produce their own collagen, but production naturally slows down as we age, typically thought to peak around age 25 and then slowly declining. Decline of natural collagen levels is one of the reasons skin starts to get less stretchy as we age and may start to sag or form deeper wrinkles.

What are the skincare claims related to collagen?

Many collagen supplements claim to contribute to healthier, more youthful looking skin, thicker hair, and stronger nails, by replenishing the collagen that is lost from our bodies with time. Is collagen the fountain of youth people have spent centuries searching for?

How can collagen be supplemented?

Collagen can be supplemented in a variety of ways. The most common form is oral supplementation through collagen powders, capsules, or gummies.

Most collagen supplements contain either bovine (from cows) or marine (from fish) collagen. Some foods, for example bone broth, also naturally contain gelatine. Powder supplements are almost always in the form of hydrolysed collagen, where the large collagen molecules have been broken down into smaller parts called peptides, which makes them dissolvable in water and easier for the body to absorb.

Marine collagen is extracted from a variety of marine animals, including fish by-products, such as scales, head, and bones, from the food sector. The most common kind of collagen found in fish is type I, although some type II collagen is also present, suggesting it may be beneficial for both skin and cartilage health.

Bovine collagen, on the other hand, comes mostly from cows, although the bovine species also includes yak, antelope and bison, among others. Other than marine collagen, bovine collagen contains mainly types I and III collagen, which are the main types of collagen found in skin.

Marine sources of collagen have been found to be easier for the body to absorb and have lower risk of causing inflammation, compared with bovine collagen.

For those following a plant-based diet, there are a range of vegan collagen supplements. Science has come a long way, and true vegan collagen can be made with genetically modified yeast or bacteria that are manipulated to produce the amino acids (protein building blocks)  that make up collagen, before adding an enzyme that rearranges the amino acids into the same structure as human collagen- pretty cool! However, most vegan collagen supplements (or ‘boosters’, as they’re often called), don’t contain this form of collagen, but rather opt for a more accessible blend of amino acids that make up collagen, as well as some other micronutrients that have been linked to collagen synthesis in the body, like Vitamin C.

What do clinical studies say about these benefits?

With the collagen supplement market being valued at almost $10 billion in 2024, it begs the question- does science back up the claimed benefits of supplementing collagen or is it not much more than a marketing gimmick?   

In general, various studies and meta-analyses have found improved skin elasticity and hydration following supplementation with hydrolysed collagen, but even scientists hesitate to make definitive statements. For one, some studies were done on mice, and the results may not be transferable to humans. Secondly, even in human studies, sample sizes are often small, which limits the strength of the conclusion, and the results were often self-reported, ie. subjects would report whether they felt like their skin seemed more elastic or hydrated after taking a supplement (or placebo) for a while, which can be difficult to confirm with more objective measures.

Some studies that show a benefit also use a combination of active ingredients, such as this one that tests a blend including collagen, biotin, vitamin C and E, so results might differ if collagen alone is supplemented.

Collagen can also be added to skincare like creams and serums, however, since  collagen fibres are too large to penetrate the outer layers of the skin, they remain on the surface and do not affect skin quality.

Are there any other benefits of collagen?

Aside from potential benefits for skin health, studies have also suggested that collagen supplementation may have a positive impact on athletes experiencing joint pain, improve symptoms in patients with osteoarthritis, and may even increase heart health. Just like the skin health related trials discussed above, it is important to remember that these studies are not conclusive and only show a link, but don’t prove causation without any further research.

Final Take

The science around collagen supplements is not yet conclusive, and the global supplement market is valued at almost half a trillion USD, so supplement companies stand to benefit from consumers feeling pressured to add various supplements to their diet.

Collagen supplementation can be tentatively linked to various health benefits, but, as always, it is important to remember that there is no quick fix for (skin) health, and a balanced diet and lifestyle should be a priority.

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