The Truth About Collagen: Is It Really Worth the Hype?

Let's start with a story. I recall a research trip in LA where we were looking at the latest health trends and products; what was new, and what might be heading across the pond to the UK soon. We stumbled across a new ready-to-drink soda - a beautifully packaged colorful range boasting its unique selling point and healthy claim - 'with added oxygen'. Oxygen! In a drink! We were pretty convinced that Californians acquired their oxygen the same way as we do in the UK - through their lungs, so why had it been added to a drink? Roll on years later and I feel pretty much the same way about collagen - understanding our physiology and how we absorb 'collagen' leads me to believe collagen supplementation may be a complete waste of money, just like the extra oxygen added to that LA soda range.

Walk into any pharmacy, health food shop, or scroll through social media, and we are met with an endless stream of collagen products. We can buy collagen powders for our morning coffee, collagen gummies, collagen drinks, and even collagen-infused beauty products. The message is simple and persuasive: consume more collagen and we can maintain youthful skin, stronger joints, healthier hair, and perhaps even slow the aging process itself.

It is little wonder that collagen supplements have become a multi-billion-pound industry. As we may search for ways to remain healthy and youthful, collagen has been marketed as the answer to many of the physical changes that accompany aging.

Yet the physiology of collagen tells a rather different story.

There is no question that collagen is vital to our health. The real question is whether spending money on collagen supplements provides any meaningful advantage. In this article, I'll help us understand why, whether it's bovine, marine, porcine or poultry, having a collagen supplement may be futile. To understand why, we need to understand the role of collagen in our body and how we absorb it.

Collagen is the most abundant protein in our body. Collagen is the body’s primary structural protein and accounts for approximately 30% of the total protein content within the human body. At a molecular level, collagen is simply a chain of simple proteins called amino acids—primarily glycine, proline, and hydroxyproline—which intertwine to form a rigid, rope-like triple helix structure. Therefore, we think of collagen as the scaffolding that holds us together. It provides strength, structure, and resilience to our skin, tendons, ligaments, cartilage, bones, and blood vessels. Without collagen, our tissues would lose much of their strength and integrity.

Unfortunately, collagen production naturally declines as we get older. From our twenties onwards, the body’s ability to synthesise new collagen gradually slows. At the same time, existing collagen fibres become increasingly damaged by factors such as ultraviolet radiation, smoking, chronic inflammation, poor nutrition, excessive alcohol intake, and elevated blood glucose levels. The consequences may become familiar to us. Skin becomes thinner and less elastic, wrinkles begin to appear, joints become stiffer, and tissue repair becomes slower. This natural decline creates the perfect marketing opportunity. If ageing is associated with collagen loss, surely consuming more collagen should replace what we have lost? The reality is considerably more complicated.

So what actually happens when we consume collagen? One of the most common misconceptions surrounding collagen supplements is that the collagen we consume somehow travels directly to our skin, joints, or connective tissues. I truly wish it did though alas this is not how human physiology works.

Collagen being a protein, and like every other dietary protein, it is broken down during digestion. Once it reaches the stomach and small intestine, digestive enzymes dismantle collagen into smaller peptides and individual amino acids. By the time collagen is absorbed into the bloodstream, it no longer exists in the same form that was originally consumed. In essence, our bodies treat collagen much like they treat protein from fish, eggs, dairy products, meat, soy or legumes. It simply becomes a collection of amino acid building blocks.

Our body then decides where these amino acid building blocks go. Once amino acids enter circulation, they become part of the body’s general amino acid pool. From there, cells utilise these building blocks according to their needs. Those amino acids may be used to build muscle tissue, manufacture enzymes, produce hormones, support immune function, produce new blood cells, create neurotransmitters, repair damaged tissues, or synthesise new collagen. The crucial point is that the body determines where these resources are needed most. There is no physiological mechanism that directs collagen consumed at breakfast specifically towards facial wrinkles, thinning hair, or aching joints. The body allocates nutrients according to biological priorities rather than marketing claims.

For balance, though, there are some studies that report improvements in skin elasticity, hydration, and joint comfort. These studies do indeed demonstrate modest benefits. However, the evidence deserves careful interpretation. A 2025 meta-analysis by Myung & Park of 23 randomised control trials found that while collagen supplements appeared to significantly improve skin hydration, elasticity, and wrinkles overall, these benefits were no longer statistically significant when only higher quality studies or studies without industry funding were analysed.  

We may think that at least collagen is a protein and therefore can boost our protein intake. An interesting irony is that collagen itself is not even a complete protein. By complete protein, we mean it contains all the essential amino acids we require - amino acids we cannot make ourselves and therefore we have to acquire them via our diet. Unlike the complete proteins in eggs, dairy products, fish, meat, and soy, collagen is an incomplete protein and contains relatively low amounts of certain essential amino acids, with tryptophan being virtually absent. This means that collagen is not especially effective as a general protein source when compared with many common foods. For most of us, a balanced diet rich in high-quality protein provides all the amino acids required for collagen synthesis while simultaneously supporting numerous other physiological processes.

Though not all is lost. As well as good quality and regular protein intake, there are actually some nutrients we need to produce collagen. Being a sophisticated biochemical process, our body requires adequate protein intake, sufficient calories, vitamin C, zinc, copper, and iron to synthesise healthy collagen. Vitamin C is particularly important because it acts as an essential cofactor in collagen synthesis. Without it, collagen production becomes severely impaired, as demonstrated by scurvy, a disease characterised by weakened connective tissues, poor wound healing, and fragile blood vessels. Therefore, back to those expensive collagen supplements - we often see vitamin C as a common ingredient in the pill, potion, or lotion. This is because they can make an actual health claim about vitamin C - among other health benefits, at certain levels, it does and is proven 'to contribute to normal collagen formation for the normal function of blood vessels, bones, cartilage, gums, skin, and teeth.' In practical terms though, we support this collagen production most effectively through a varied diet that includes fruits, vegetables, lean proteins, dairy products, legumes, nuts, and seeds.

If our goal is to effectively preserve collagen, the strongest scientific evidence points towards lifestyle factors rather than supplementation. Protecting our skin from excessive sun exposure, avoiding smoking, maintaining adequate protein intake, exercising regularly, controlling blood glucose levels, and consuming sufficient vitamin C rich foods all play important roles in preserving collagen integrity. These interventions may not generate the same excitement as oxygenated soda or a new supplement launch, but they are supported by a far stronger understanding of human physiology.

So the bottom line is collagen is unquestionably essential for health. Every tendon, ligament, blood vessel, bone, and layer of skin depends upon it. However, the assumption that consuming collagen supplements automatically translates into increased collagen within our tissues oversimplifies how the body works. When we consume collagen, it is largely broken down into amino acids that enter the same metabolic pool as amino acids derived from other dietary proteins. The body then determines how those building blocks are used. While collagen supplements may offer modest benefits in some circumstances, particularly for individuals with low protein intake or specific clinical needs, the evidence suggests that they are far from the miracle solution often portrayed in advertising.

For many, collagen supplements may simply represent an expensive way of obtaining amino acids that could be acquired more economically through a boiled egg & soldiers.

The physiology is clear. Our body’s collagen factory is far more dependent upon adequate nutrition, regular exercise, vitamin C, and healthy lifestyle habits than it is on any supplement.

The uncomfortable truth for the supplement industry is that the most effective collagen strategy may not be found in a capsule at all. It may already be sitting on our plate.

Happy eating,

Nina Thomas

BSc (Hons), MSc, ANutr

Registered Associate Nutritionist & Food Scientist

Bridgford & Bingham Nutrition              

21 Brickyard Lane

East Bridgford

Nottingham

NG13 8NJ

Call: 07958 765337

​www.bridgfordbinghamnutrition.co.uk