Collagen: Super Supplement or Just Another Trend?
I have lots of conversations with clients about whatever amazing new trend or fad is being pushed into their social media streams, and I get asked for my opinion on all of them.
Today, a nice discussion was about the wonders of collagen and whether it's the new super supplement that apparently all women should be taking.
I normally listen to what clients have been told online, make a mental note of it, and then go away and have a dig into the actual research before coming back with an opinion.
So here we go...
Is collagen really something we should all be taking?
And perhaps more importantly, once we get past the advertising, influencers and before-and-after photographs, what does the research actually say?
Interestingly, this isn't one of those supplements where I can simply say, "Don't waste your money." There is actually some decent research behind collagen.
But — and there's nearly always a but when we start looking properly at supplements — the evidence is much stronger for some of the claims than others.
And despite collagen being heavily marketed towards women, particularly for skin and "anti-ageing", it's certainly not just a women's supplement. Quite a lot of the research looking at collagen, exercise, tendons and connective tissue has actually been conducted in men.
So let's have a proper look at what collagen is, the different types, what it might realistically do for women and men, how much people have been taking in the research and whether things such as taking it with vitamin C actually make a difference.
First of all, what actually is collagen?
Collagen is one of the major structural proteins in the human body.
It's an important component of:
skin
bones
tendons
ligaments
cartilage
blood vessels
connective tissue
So you can probably see immediately why supplement companies have become quite excited about it.
If collagen is found in our skin, bones, joints and tendons, surely eating more collagen must give us better skin, stronger bones and healthier joints? Unfortunately, human biology isn't usually quite that straightforward. And that's where we need to separate what sounds logical from what has actually been demonstrated in research.
There are numerous types of collagen, but Types I, II, III and IV are the ones you're most likely to hear about.
Type I: This is the most abundant collagen in the human body. It's found predominantly in: skin, bone, tendons, ligaments and teeth. This is why Type I tends to feature heavily in products aimed at skin, bone and connective tissue.
Type II: Type II is predominantly found in cartilage. Not surprisingly, this is the type you're likely to see in supplements marketed towards joint health.
Type III: Type III is commonly found alongside Type I and is present in: skin, muscles, blood vessels and internal organs.
Type IV: Type IV collagen is mainly found in basement membranes — specialised structures supporting and separating tissues within the body.
For most people looking at a tub of collagen in a health-food shop, however, there's another distinction that's probably more useful.
Hydrolysed collagen or collagen peptides
Most collagen powders you'll see are hydrolysed collagen, often labelled as collagen peptides. This simply means the collagen protein has already been broken into smaller chains of amino acids called peptides.
You'll occasionally hear the argument that taking collagen is pointless because your digestive system simply breaks it down anyway. That's not really the issue. Collagen is digested, and collagen-derived amino acids and peptides can enter the circulation.
The more interesting question is:
What does your body subsequently do with them?
And that's where the research starts becoming interesting…
Why might collagen become more relevant as we get older?
Forget the beauty industry for a moment. This is where I personally think collagen becomes considerably more interesting.
As both men and women get older, maintaining:
muscle mass
bone density
tendon capacity
joint function
physical strength
becomes increasingly important.
For women, the decline in oestrogen associated with menopause adds another important consideration, particularly around bone health. For men, ageing is also accompanied by losses in muscle mass, strength and connective-tissue function.
That doesn't mean collagen is going to prevent ageing. Unfortunately, nobody has found that supplement yet. But there are some areas where collagen supplementation might provide an additional benefit.
Collagen and joint health
This is probably one of the better-supported uses. A 2024 meta-analysis examined 35 randomised controlled trials involving 3,165 people with osteoarthritis.
Compared with control treatments, collagen derivatives produced small-to-moderate improvements in pain and improvements in physical function. Importantly, the researchers rated the certainty of the evidence as moderate for pain and high for function.
That's considerably more convincing than an influencer telling you their knees feel fantastic since somebody started paying them to advertise collagen. But let's keep this in context. It doesn't mean collagen cures osteoarthritis. And it certainly doesn't mean somebody with painful knees should stop exercising and start drinking collagen instead.
Strengthening the muscles surrounding the joint, maintaining an appropriate bodyweight, staying physically active and following appropriate medical or physiotherapy advice remain far more important. Collagen might provide an additional tool.
That's a very different claim.
Collagen and bone health in women
This is probably one of the most interesting areas specifically for women. Bone density becomes increasingly important around and following menopause.
A randomised, double-blind, placebo-controlled trial investigated 131 postmenopausal women with age-related reductions in bone mineral density. The women received either a placebo or 5 g of specific collagen peptides per day for 12 months.
The collagen group experienced better changes in bone mineral density at both the lumbar spine and femoral neck, along with favourable changes in bone-turnover markers.
More recent pooled research has also reported improvements in bone mineral density and bone-turnover markers, although there is considerable variation between studies.
So I'd describe the evidence as promising. But there's an important distinction here… If a woman asked me what she should prioritise for maintaining her bones as she gets older, collagen wouldn't suddenly jump to the top of the list. I'd still be talking about:
progressive resistance training
weight-bearing activity
adequate protein
adequate calcium
vitamin D
and appropriate medical assessment where osteopenia or osteoporosis is a concern. Collagen might complement those things. It doesn't replace them.
What about men?
This is where some people might be surprised. A significant amount of the exercise and connective-tissue research involving collagen has actually been conducted in men.
For example, researchers have investigated collagen supplementation alongside resistance training in young recreationally active men, looking at changes in muscle mass, strength and body composition.
Other trials have investigated collagen and tendon adaptation specifically in male participants. One randomised controlled study involving 50 moderately active men found that collagen peptides combined with 14 weeks of high-load resistance training produced greater changes in patellar tendon morphology than resistance training alone.
Another trial involving 40 healthy young men investigated Achilles tendon properties following 14 weeks of high-load resistance training combined with collagen peptides. More recently, researchers studying middle-aged resistance-trained men found that hydrolysed collagen consumed before resistance exercise increased collagen synthesis in a dose-responsive manner.
So collagen certainly isn't exclusively a "women's supplement". If anything, the potential effects on tendons and connective tissue make it particularly interesting for both men and women who are training as they get older.
Is collagen good for building muscle?
This is where I think people need to be careful. Collagen is protein. But that doesn't automatically make it the best protein for building muscle.
Collagen has a very different amino acid profile from proteins such as whey, milk, eggs, meat, fish and soya.
It's particularly rich in glycine, proline and hydroxyproline - amino acids associated with connective tissue. But it's relatively poor in essential amino acids such as leucine that are particularly important for stimulating muscle protein synthesis.
So if you're currently having a 25–30 g whey protein shake after training, I wouldn't replace that with 10 g of collagen powder and assume they're equivalent. They're not. Research shows interesting changes in body composition when men combine collagen with resistance training.
But again, there's a rather large elephant in the room. They're doing resistance training. And resistance training works extremely well. So I'm reluctant to give the supplement all the credit for adaptations primarily produced by weeks or months of progressive training.
If maintaining or increasing muscle is your priority, I'd still focus on: resistance training + sufficient high-quality dietary protein.
Think of collagen as potentially providing something additional, particularly for connective tissue.
Where collagen gets really interesting: tendons
This is probably the area that interests me most from a training perspective. Tendons contain large amounts of collagen. And unlike muscle, where we're particularly interested in essential amino acids and leucine, connective tissue has a different protein composition.
The theory is therefore quite attractive: Provide the amino acids used heavily within collagen-rich tissue and combine them with the mechanical stimulus of exercise. Controlled studies now suggest this may influence tendon adaptations.
But again, not every study has found a benefit. One double-blind trial had young recreationally active men consume 15 g of collagen peptides per day while completing 15 weeks of lower-body resistance training.
Researchers found no additional improvement in the measured tendon adaptations compared with placebo. Compare that with the trial mentioned earlier that found greater patellar tendon morphological adaptations after 14 weeks of high-load resistance training with specific collagen peptides. That's science.
Sometimes the results don't agree. Which is exactly why we should be suspicious whenever somebody finds one positive study and announces: "Science proves collagen rebuilds your tendons!"
It doesn't. The emerging evidence is interesting. It isn't definitive.
What about skin?
Now we arrive at the claim most people probably associate with collagen. Younger-looking skin. Reduced wrinkles. Better hydration. Improved elasticity. There is certainly positive research.
A systematic review and meta-analysis of 26 randomised controlled trials involving 1,721 participants found that hydrolysed collagen supplementation improved skin hydration and elasticity compared with placebo. Sounds convincing. But this is where reading beyond the headline becomes particularly important.
A 2025 systematic review and meta-analysis examined 23 randomised controlled trials and specifically looked at study quality and funding source. When all of the trials were pooled together, collagen appeared to improve skin hydration, elasticity and wrinkles. However, when researchers looked specifically at studies not funded by pharmaceutical companies, those benefits disappeared.
Higher-quality studies also failed to demonstrate significant improvements across those outcomes. That's a really important finding.
So if somebody tells you: "Collagen has been scientifically proven to reverse skin ageing." I'd be very cautious. There may be a benefit. There are positive studies.
But I'd describe the evidence as mixed rather than conclusive, particularly when commercial funding and study quality are taken into consideration.
Do you need vitamin C with collagen?
Now for one of the questions I hear a lot. "Don't you need to take collagen with vitamin C or you can't absorb it?" Not exactly. This is one of those situations where a little bit of science has turned into a rather bigger marketing claim.
Vitamin C isn't the key that allows you to absorb collagen. Collagen peptides are digested and absorbed. You don't suddenly stop absorbing them because you didn't eat an orange at the same time. But...
Vitamin C IS important for making collagen. And that's an important distinction. Vitamin C acts as an essential cofactor for enzymes involved in normal collagen synthesis. So having adequate vitamin C status matters. But adequate and enormous aren't the same thing.
If you're eating a decent diet containing fruit and vegetables, there's no convincing evidence that swallowing huge doses of vitamin C alongside your collagen suddenly allows your body to manufacture enormous quantities of additional connective tissue.
You don't need 1,000 mg of vitamin C every time you take collagen. Foods such as:
peppers
kiwi fruit
berries
oranges
broccoli
•Brussels sprouts
potatoes
tomatoes
can all contribute vitamin C. For most people, I'd concentrate on having a good diet rather than worrying about another supplement.
What about taking collagen and vitamin C before training?
This is slightly more interesting. A frequently cited randomised crossover study involved eight healthy men.
They consumed either placebo or 5 g or 15 g of vitamin-C-enriched gelatin, followed one hour later by a short bout of skipping designed to stimulate collagen synthesis.
The participants consuming 15 g of gelatin showed a substantial increase in a blood marker associated with collagen synthesis.
A later study involving 10 recreationally active men compared different vitamin-C-enriched collagen/gelatin formulations before exercise and again found increases in circulating amino acids, although the collagen-synthesis marker results were variable and didn't reach statistical significance between treatments.
So the idea of taking collagen approximately 30–60 minutes before loading a tendon is scientifically plausible. But let's keep this in perspective. The original study involved eight men. That's a long way from demonstrating that everyone who takes collagen and vitamin C before training will avoid tendon injuries.
I'd describe it as: Interesting, inexpensive and potentially useful - but not essential.
So when should you take collagen?
If you're simply taking collagen for general joint health, the current research doesn't give us a compelling reason to obsess over the time of day.
Consistency is probably more important. If your objective is specifically tendon or connective-tissue adaptation, then taking collagen roughly 30–60 minutes before resistance training or rehabilitation exercises is a reasonable strategy based on the available evidence.
But here's the bit I'd really like people to remember: The exercise is probably more important than the supplement.
Nutrition provides building blocks. Loading provides the stimulus telling the tissue that it needs to adapt. Taking collagen before sitting on the sofa watching Netflix probably isn't going to produce the same response.
How much collagen?
There isn't one magic dose because studies investigate different products, populations and outcomes. But we can look at what's actually been used in research.
Bone health - The postmenopausal bone study discussed earlier used: 5 g per day for 12 months.
Skin - Trials vary considerably, but doses of hydrolysed collagen in the low single-digit grams up to around 10 g per dayare common in the research. Again, I'd remain cautious about promising cosmetic results.
Exercise and muscle studies - A number of resistance-training studies have used: 15 g per day.
Tendon-focused research - Protocols vary considerably.
Studies have investigated approximately 5–30 g, depending on the collagen product and experimental design. A recent trial in middle-aged men, for example, combined 30 g hydrolysed collagen plus 50 mg vitamin C with 12 weeks of progressive resistance exercise and reported greater improvements in some patellar tendon properties than training with placebo.
That doesn't mean everybody suddenly needs 30 g. It simply shows why I don't like giving one universal "collagen dose". It depends on why you're taking it.
Marine, bovine or porcine collagen?
This is another area where marketing tends to get ahead of evidence.
Marine collagen - Derived from fish and generally rich in Type I collagen. Often marketed for skin.
Bovine collagen - Derived from cattle and commonly provides Types I and III.
Porcine collagen - Derived from pigs and also generally provides Types I and III.
Type II/cartilage-derived collagen - Usually marketed more towards joint health.
Is expensive marine collagen automatically better than bovine collagen? I wouldn't make that assumption. A meta-analysis examining skin outcomes found that collagen source didn't significantly alter improvements in skin elasticity, although hydration results differed between subgroups.
So don't assume the tub saying "Premium Marine Beauty Collagen" is scientifically superior because it costs twice as much.
I'd be far more interested in: What form of collagen is it? How much does it contain? What are you actually taking it for? Does the research support that formulation and dose?
My practical tips if you're thinking about taking collagen
If you decide you want to try it, I'd keep things fairly simple.
First, get your normal protein intake sorted. Particularly if you're over 40 and trying to maintain muscle. Collagen isn't a replacement for high-quality complete protein.
Decide why you're taking it. "Because it's good for you" isn't a particularly useful reason. Are you interested in joints, tendons, bone or skin? The evidence isn't equally strong for all of them.
Don't obsess about vitamin C. Make sure your diet provides enough. You don't need huge vitamin C doses to "absorb" collagen.
If you're targeting tendons, consider taking it before training. Approximately 30–60 minutes beforehand is a reasonable evidence-informed strategy, but it's certainly not proven to be essential.
Train the tissue. This is probably the most important point in the entire article.
Don't expect immediate results. The meaningful studies generally last weeks or months, not three days.
Don't replace whey or good food with collagen. Particularly if muscle retention or growth is the objective.
Be sceptical of marketing. "Beauty collagen", "female collagen", "men's collagen", "anti-ageing collagen" and "premium collagen" are marketing terms, not evidence of effectiveness.
So, should women take collagen?
Possibly.
For postmenopausal women particularly concerned about bone health, the research is interesting enough that collagen could be considered alongside resistance training, adequate protein, calcium, vitamin D and appropriate medical care.
For women taking it purely because they've been told they need collagen after 40 to stop their skin ageing? I'm much less convinced. The skin evidence is considerably less impressive once study quality and funding are taken into account.
Should men take collagen?
Again: Possibly.
For a man already consuming enough high-quality protein and regularly resistance training, collagen may have some interesting applications around tendon and connective-tissue adaptation, particularly as he gets older.
Research in middle-aged men provides some interesting evidence that hydrolysed collagen can increase the collagen-synthesis response to resistance exercise. But I wouldn't recommend it as your primary muscle-building protein.
If the choice is between sorting out your daily protein intake and buying collagen... Sort the protein out first.
If the choice is between starting resistance training and buying collagen... Start training.
Then we can talk about supplements.
The Griffin Fit takeaway
So after having dug through the research, where have I ended up? Collagen isn't rubbish. But it isn't a super supplement either.
There is relatively good evidence for osteoarthritis symptoms, with a substantial meta-analysis of randomised trials reporting improvements in pain and physical function.
There is promising evidence around bone health, particularly in postmenopausal women, although collagen should be viewed as an addition to established bone-health strategies rather than a replacement for them.
There is some genuinely interesting emerging research around tendons and connective tissue, particularly when collagen supplementation is combined with resistance exercise. But studies don't all agree.
The research around skin looks considerably less convincing once we start examining study quality and commercial funding. And collagen shouldn't be confused with a high-quality protein for maintaining or building muscle.
So for both men and women, my priorities haven't really changed:
Lift weights
Eat enough high-quality protein
Eat plenty of nutritious food
Stay physically active
Look after your bones
Sleep properly
Progressively load your muscles and tendons
And once those things are in place? Then collagen might be worth considering. Because that's what a supplement is supposed to do. Supplement what you're already doing. Not replace it.
A scoop of collagen might provide some useful building blocks. But your body still needs a reason to use them. And that's where the training comes in.
Research sources
All of the research below is peer-reviewed. I've deliberately prioritised randomised controlled trials, systematic reviews and meta-analyses rather than supplement-company articles or social-media claims.
Liang CW, Cheng HY, Lee YH, et al. (2024). Efficacy and safety of collagen derivatives for osteoarthritis: A trial sequential meta-analysis. Osteoarthritis and Cartilage, 32(5), 574–584. Meta-analysis of 35 RCTs and 3,165 participants.
König D, Oesser S, Scharla S, Zdzieblik D, Gollhofer A. (2018). Specific Collagen Peptides Improve Bone Mineral Density and Bone Markers in Postmenopausal Women—A Randomized Controlled Study. Nutrients, 10(1), 97.
Sun et al. (2025). Efficacy of collagen peptide supplementation on bone and muscle health: a meta-analysis. Meta-analysis examining bone mineral density, bone-turnover markers and muscle outcomes.
Myung SK, Park Y. (2025). Effects of Collagen Supplements on Skin Aging: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. American Journal of Medicine, 138(9), 1264–1277. Particularly useful because the authors analysed outcomes according to study quality and funding source.
Pu SY, Huang YL, Pu CM, et al. (2023). Effects of Oral Collagen for Skin Anti-Aging: A Systematic Review and Meta-Analysis. Nutrients. Included 26 RCTs and 1,721 participants.
Shaw G, Lee-Barthel A, Ross ML, Wang B, Baar K. (2017). Vitamin C-enriched gelatin supplementation before intermittent activity augments collagen synthesis. American Journal of Clinical Nutrition, 105(1), 136–143.
Lis DM, Baar K. et al. (2019). Effects of Different Vitamin C-Enriched Collagen Derivatives on Collagen Synthesis.International Journal of Sport Nutrition and Exercise Metabolism.
Kirmse M, Oertzen-Hagemann V, de Marées M, et al. (2019). Prolonged Collagen Peptide Supplementation and Resistance Exercise Training Affects Body Composition in Recreationally Active Men. Nutrients, 11(5), 1154.
Jerger S, Centner C, Lauber B, et al. (2022). Effects of specific collagen peptide supplementation combined with resistance training on Achilles tendon properties. Randomised controlled trial involving healthy men completing high-load resistance training.
Lee J, et al. (2023). The Effect of Specific Bioactive Collagen Peptides on Tendon Remodeling during 15 wk of Lower Body Resistance Training. Randomised, double-blind, placebo-controlled trial.
Nulty CD, et al. (2024). Hydrolyzed collagen supplementation prior to resistance exercise augments collagen synthesis in a dose-response manner in resistance-trained, middle-aged men. American Journal of Physiology-Endocrinology and Metabolism.
Shaw G, et al. (2021). Collagen and Vitamin C Supplementation Increases Lower Limb Rate of Force Development.International Journal of Sport Nutrition and Exercise Metabolism. The intervention used 20 g hydrolysed collagen plus 50 mg vitamin C before training in young male athletes.
This article is for general education and isn't individual medical advice. Anyone with osteoporosis, osteoarthritis, persistent tendon or joint pain, kidney disease, food allergies or another medical condition should discuss supplementation and treatment with an appropriate healthcare professional.