Understanding collagen: Mechanisms, misconceptions and what really matters
Collagen is one of the most widely used, yet often misunderstood, nutrients in health. With a growing number of proposed health benefits, alongside multiple sources, types, and plant-based alternatives, it can be difficult to cut through the noise. In particular there’s a lot of discussion about whether there is any point to taking collagen supplements. So, let’s take a detailed look at how collagen works in the body, address common misconceptions, and explain why collagen can be effective, as long as you use the right source, type, quality and formulation.
What is collagen and why is it important?
Collagen is the most abundant protein in the body, providing structure, strength, and elasticity to skin, joints, bones, and connective tissue. Collagen declines with age, reflecting a gradual reduction in the body’s ability to synthesise and maintain it. This process is also influenced by lifestyle and environmental factors, including diet and nutrition, sun exposure (UV-induced damage), smoking, exercise and stress. Collectively, these factors contribute to changes such as reduced skin elasticity, the appearance of fine lines, and decreased joint comfort or flexibility over time.
Misconception 1: Collagen cannot be absorbed, so there is no point in supplementing it
A common belief is that collagen is completely broken down into individual amino acids during digestion and simply reused to build various proteins, including collagen. It’s also often suggested that collagen is difficult to digest.
In reality, whole collagen molecules are too large to be absorbed intact. For this reason, most collagen supplements use hydrolysed collagen peptides, where the collagen has already been broken down into smaller peptides. These formulations provide a mix of peptides (including dipeptides and tripeptides) and research suggests some of these peptides can be absorbed intact and may help directly support collagen production and connective tissue function.
Misconception 2: Collagen is just a source of collagen
Collagen peptides may do more than simply provide structural building blocks. Certain collagen-derived peptides can also act as signalling molecules, helping stimulate cells involved in connective tissue production, including fibroblasts (skin), chondrocytes (cartilage), and osteoblasts (bone).
Collagen peptides may also help reduce connective tissue breakdown by influencing matrix metalloproteinase (MMP) enzymes. (Wang, 2021)
Importantly, peptide profiles vary depending on the collagen source and processing, which is why formulation quality matters. (Dierckx, 2024) As a result, not all hydrolysed collagen products provide the same peptide composition or level of consistency.
Misconception 3: All collagen is the same
Collagen formulations can vary by collagen type, source and approach, and these differences influence their structure and function in the body.
Common collagen types
- Type I – skin, bones, tendons and ligaments
- Type II – cartilage
- Type III – connective tissue alongside Type I
Common collagen sources
- Marine collagen – predominantly Type I, often used for skin, gut and general connective tissue support
- Bovine collagen – typically Types I and III
- Cartilage-derived collagen – commonly associated with Type II collagen and joint-focused formulations
- Hydrolysed collagen peptide formulations - the most common form used in supplements. These provide collagen-derived peptides alongside amino acids
- Vegan collagen formulations - provide amino acid blends associated with collagen structure to support collagen synthesis
- Collagen “boosters” - provide supportive nutrients such as vitamin C, zinc, copper and antioxidants that help support collagen production and protect existing collagen from breakdown.
Rather than one approach being universally better, these formulations support healthy collagen levels through different but complementary mechanisms.
Misconception 4: Vegan collagen is the same as collagen
Collagen is a structural protein derived from animal sources, so there is no direct vegan equivalent. However, collagen can be supported through collagen-supporting formulations, which provide nutrients such as vitamin C, rutin, zinc, and copper, and targeted amino acid formulations, which supply the building blocks required for collagen production.
Ingredients such as Vollagen (vegan collagen) fall into the latter category. Produced via fermentation of plant-derived substrates, they deliver amino acids involved in collagen structure, including glycine, proline, and hydroxyproline. This approach provides the core building blocks for collagen synthesis, delivers them in ratios aligned with human collagen, and ensures a consistent, readily usable amino acid profile.
Misconception 5: All collagen products are of the same quality
Collagen products can vary considerably in quality, which may influence consistency, reliability, and overall trust in the product. Key considerations include:
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Purity, with minimal unnecessary additives
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Controlled processing to ensure consistent peptide profile
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Transparent sourcing and manufacturing standards
For marine collagen, sustainability is often a key consideration, with certifications such as Friend of the Sea indicating responsible sourcing practices. For bovine collagen, factors such as traceability, animal welfare, and farming standards are important.
Misconception 6: Collagen is only relevant as we age
While collagen production declines with age, it remains essential throughout life. Collagen is continuously broken down and rebuilt, with turnover influenced by physical activity, nutrition, and lifestyle. Its relevance therefore extends beyond ageing, particularly during periods of increased demand such as physical activity, recovery, environmental exposure, or where nutritional intake may limit collagen synthesis.
Misconception 7: Collagen alone is enough for skin health
Collagen is just one component of healthy skin. Optimal skin structure and appearance also depend on nutrients that support collagen formation, help protect against its breakdown, maintain hydration, and defend against environmental stress.
Vitamin C contributes to normal collagen formation, hyaluronic acid helps maintain skin hydration and elasticity, and antioxidants such as vitamin C and rutin play a key role in protecting the skin from oxidative damage, and the breakdown of collagen. For this reason, well-designed skin formulas often combine collagen with complementary nutrients to take a more holistic approach to skin health.
Misconception 8: Collagen can replace dietary protein
Collagen is not a complete protein and does not provide the full range of amino acids required for general protein needs such as muscle maintenance. It is best considered a targeted protein for connective tissue support, rather than a replacement for dietary protein.
Misconception 9: Collagen works immediately
Collagen supplementation works gradually, with benefits building over time rather than appearing instantly. Studies assessing outcomes such as skin or joint health typically measure improvements over several weeks of consistent intake. (Asserin, 2015; Dähnhardt, 2024; de Miranda, 2021)
Misconception 10: You can easily get enough collagen from food alone
Collagen and its building blocks can be obtained through the diet, particularly from animal-based foods and general protein intake. However, typical diets may not consistently provide sufficient collagen-specific amino acids, and collagen synthesis also depends on key nutrients such as vitamin C, zinc, and copper. For this reason, supplementation may offer a more consistent and targeted approach, particularly where intake is limited or requirements are increased.
Key takeaways
Collagen is not a single, uniform ingredient, and formulation, including type, source, and production method, influences how it functions in the body. It is also only one part of the picture. Nutrients that support collagen synthesis and help protect against its breakdown play an essential role too.
Collagen can be supported in multiple ways, including collagen peptides, targeted amino acid formulations, and supportive nutrients, which act through complementary mechanisms.
References
Asserin, J., et al. (2015). The effect of oral collagen peptide supplementation on skin moisture and the dermal collagen network: evidence from an ex vivo model and randomized, placebo-controlled clinical trials. Journal of cosmetic dermatology, 14(4), 291–301.
Dähnhardt, D., et al. (2024). Restoration of the Ultrastructural Integrity of the Dermal Collagen Network by 12-Week Ingestion of Special Collagen Peptides. Dermatology and therapy, 14(9), 2509–2521.
de Miranda, R. B., Weimer, P., & Rossi, R. C. (2021). Effects of hydrolyzed collagen supplementation on skin aging: a systematic review and meta-analysis. International journal of dermatology, 60(12), 1449–1461.
Dierckx, S. et al. (2024) Collagen peptides affect collagen synthesis and the expression of collagen, elastin, and versican genes in cultured human dermal fibroblasts. Frontiers in medicine, 11, 1397517
Wang H. (2021). A Review of the Effects of Collagen Treatment in Clinical Studies. Polymers, 13(22), 3868.
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