At first glance, the research on collagen supplementation from an injury recovery perspective is mixed. I will be the first to admit that when I first looked into it, I brushed it off as another one of those supplements getting unnecessary hype without enough promising research behind it.
I hold myself to a high standard as an evidence-based practitioner and I am typically not the quickest person to hop on board newer trends, even if they come out of the gates strong with 1-2 promising studies. Because of this, I was quite dismissive of collagen.
This was until another colleague of mine in the dietetics world pointed me in the direction of a podcast that featured Professor Keith Baar, which started the process of opening my eyes and seeing that there actually could be something is something behind this.
The key thing that was highlighted in this podcast was that although the research might look mixed, once you account for a few important variables, it actually is far more consistent. All the studies meeting a specific criterion regarding dosage, timing and pairing with a certain vitamin appear positive. Meanwhile, the studies missing any of those variables appear to not show any benefits.
Collagen Supplementation Research Is in Its Infancy
I cannot stress enough that while I am going to be pointing to a lot of the potential benefits of collagen supplementation in this article, it is still early days. I am confident I’m going to need to update this article relatively frequently over the next few years.
During the podcast I referred to, Professor Baar mentioned that he was involved in pretty much all the research on collagen supplementation and tissue repair.
I took this as an off-hand comment that was a bit of an exaggeration. But when I started going down the rabbit-hole of looking through all the research (partially stimulated through my own issues with patellar tendinopathy which was effecting my own performance in basketball and powerlifting), I realised it was no exaggeration.
I even went out of my way to search for some research in the area that I thought he wouldn’t have been involved in.
Personally, I had been at the AIS doing further training to become an Accredited Sports Dietitian during 2017. At the time Greg Shaw was one of the leading dietitians there and had just completed a study on the effects of bone broth on collagen synthesis. Bone broth contains gelatin, which can provide collagen and theoretically could provide the same benefits as directly supplementing with collagen (although I’ll discuss later why bone broth probably is not a good option for this).
This was the first study I looked for when I was looking for non-Baar research. When I found this study thinking that all the authors would have been Australian-based, once again I was surprised to see Professor Baar’s name on there as an author as well. The guy is everywhere when it comes to collagen research.
While a lot of the research is positive, it is worth highlighting that the majority of research has been over the last 3-4 years, with relatively small sample sizes. One person has been the driving force behind it, which also makes me question it a little bit. Even though there is a lot of promise, there are a lot of stones still left unturned.
What Injuries Specifically Can Collagen Supplementation Help With?
Our tendons, ligaments, bones and cartilage all contain collagen as their main protein. Theoretically, collagen supplementation could help with any injury that involves those areas.
Specifically though, while looking through the research it appears as though most of the research has been focused on tendons, with a little bit being performed on ligaments (for example this case study on ACL tear recovery).
It is worth noting that musculoskeletal injuries make up the vast majority of injuries that occur in athletes, at roughly 70% of all injuries. Since collagen might be able to help speed up the recovery of musculoskeletal injuries, it theoretically could help speed up the recovery of the majority of injuries.
If the research continues to trend in the direction I’m predicting it will be based on what is currently available, collagen supplementation could become one of the most popular supplements for injury prevention and recovery.
How to Use Collagen Supplements for Injury Recovery
The specific protocol I recommend is 15-25g of gelatin or hydrolysed collagen, with 50mg (or higher) vitamin C, 40-60 minutes before training/rehab.
There is no noticeable difference between hydrolysed collagen and gelatin from an outcomes perspective that has been shown in the research, although hydrolysed collagen typically is easier to consume for most people.
The timing is targeted at 40-60 minutes before exercise because that is when the levels of amino acids from the supplement peak in the blood. Specifically, the 4 main amino acids that collagen is high in are proline, glycine, lysine and arginine.
Since collagen supplementation cannot really “target” the injured area naturally, the best we can do is attempt to time it so that the relevant amino acid levels are at their highest during exercise.
During exercise, the connective tissue will pull liquid in, like a sponge to a certain degree. Theoretically, because that liquid is high in the relevant amino acids, that is why collagen synthesis rates increase significantly, helping to speed up recovery.
There is no evidence to suggest that the supplement NEEDs to be pre-training. What I mean by that, is that there haven’t been any studies involving collagen supplementation post-workout.
So right now, we have some evidence suggesting that pre-training works, but none suggesting that post-training would/wouldn’t work. Therefore, in my opinion, the safest route is to take it pre-workout for now until more research is published.
Vitamin C is necessary as part of one of the main enzymatic processes involved in collagen production. Therefore, if you don’t have vitamin C in your system, the collagen supplement won’t work. This is one potential issue that has been relevant to the interpretation of collagen research.
Since the key studies have been undertaken in a fasted state, vitamin C supplementation has been vital. But it leaves a lot of questions still unanswered.
For example, do we need the vitamin C supplement? What if people just ate their usual diet? Would they have enough vitamin C in their system already if they were training in a non-fasted state?
We also do not have a specific dosage that’s necessary. I’ve seen anywhere from 50mg to 500mg in the research, and to put that in context, the RDI in Australia is 45mg per day.
For more insight into how this can practically be applied, my interpretation is that it is best to follow this protocol before every session that could promote collagen synthesis in the injured area.
One example of this was Greg Shaw’s case study involving Rugby Union players who took 15g gelatin with vitamin C 3x a day since they were doing their rehab exercises 3x a day.
If your training/rehab is set up appropriately, collagen synthesis should occur anyway. This protocol is just designed to enhance that significantly.
Variables in the Research
Some of the reasons why the research appears to be mixed is due to:
- The dosage of collagen being too low.
- No inclusion of vitamin C.
- Timing of the supplementation.
If any of these factors are off, the protocol won’t be anywhere near as effective.
Using the dosage as an example, if you look on the back of a collagen supplement, most of them have <15g of collagen in them per serve. There are exceptions of course. But you need to know what you are looking for.
The research appears to be pretty clear that 15g or higher appears to be the sweet spot for maximising collagen synthesis.
As stated earlier, vitamin C is vital for collagen synthesis. Professor Baar even mentioned that one of the projects his lab was working on (which looks unpublished as far as I can tell) ended up with a massive flaw due to them leaving the vitamin C supplement exposed to sunlight. Since vitamin C is sensitive to heat, the supplement became ineffective. Therefore, the results they got from that study were in complete contradiction to all the other work that had been done.
The other aspect is timing. If the supplement is not taken near the workout, then it likely is going to be ineffective.
As stated previously, the supplement doesn’t specifically target the injured area. It just gets broken down into amino acids and absorbed. Since a large portion of the body is made up of collagen, these amino acids are needed in a lot of places, not just the parts that are injured.
How Effective Is It?
It’s quite difficult to measure things such as tendon function in humans. Obviously, you can’t take the tendon out of an athlete and test it. Instead, a lot of information needs to be inferred.
The biggest mechanism that can be observed is collagen synthesis.
To observe levels of collagen synthesis, researchers measure P1NP (Pro-collagen 1 n-terminal peptide) as a marker for how much collagen is being made.
Irrelevant of consuming collagen, collagen synthesis will likely still occur. However, the research is pretty clear that collagen synthesis is noticeably higher when supplementation is involved. Some research shows that the rate of collagen synthesis could potentially even double with supplementation.
In terms of specific outcomes, there is a case study of an NBA player undergoing an 18-month rehabilitation protocol while utilising collagen supplementation that demonstrates fascinating outcomes.
Without going into details, this player had severe patellar tendinopathy and had a “hole” in their patellar tendon. And this “hole” is representative of the injured area. This hole traditionally still remains post-rehab, even if the treatment has been successful. A lot of experts in this field talk about “treating the doughnut (e.g. the healthy tendon around the injured area), not the hole” with the understanding that it is unlikely that the hole will ever heal.
But through following this protocol, the player no longer had a hole in their tendon, as shown via the MRI below.
It’s also worth noting that in Australia’s NBL, 52.3% of players reported patellar tendon pain that limited performance. This is an insanely high number. So if the promising research continues to progress, it will be a good thing for a large number of athletes.
The last aspect that is worth considering, is that when thinking of effectiveness, it’s also worth splitting that up into the separate categories of time and outcomes.
From a time perspective, it looks like collagen supplementation likely could reduce the time it takes to recover from an injury.
For an elite athlete, maybe it is important to recover from an ACL surgery and get back onto the field in a specific timeframe. For a weekend warrior, does it matter as much if the rehab takes slightly longer?
Collagen supplementation is an added cost. For some people, it might not be worth it. For others, it could be.
Could You Just Consume Enough Protein and Get the Same Result?
This is a great question. If you’ve been paying attention, you will have noticed that collagen supplements and gelatin supplements still partly breakdown into their amino acids prior to being utilised for their purposes. Therefore, you could assume that the amino acids are the key, not necessarily the specific supplement.
This is not a well-researched area yet though, so there is not a great answer.
Theoretically, the advantage of hydrolysed collagen over something like whey protein is that it is high in the specific amino acids of lysine, glycine, arginine and proline. Meanwhile, whey protein is high in amino acids that are more useful for building muscle, such as leucine.
So, based on that, collagen supplementation makes more sense. Although that still leaves the question as to whether consuming a large enough amount of protein to have an abundance of those amino acids would still be as effective.
At the time of the podcast that Professor Baar was a guest on, he mentioned that it would be interesting to compare whey protein to hydrolysed collagen or gelatin, to see if there was indeed a difference.
Unfortunately, to the best of my knowledge, that research still has not been done. But we are lucky that casein protein has since been tested.
It turns out that casein protein does not increase collagen synthesis when compared to a placebo. Since hydrolysed collagen and gelatin do increase collagen synthesis when compared to a placebo, this is another tick in favour of collagen supplementation over simply just consuming sufficient total protein.
Is It Possible to Consume Sufficient Collagen Through Food?
This is an important question for those who prefer to minimise their supplement usage. And the answer is yes, you can get sufficient collagen through food if you desire. It is difficult though.
Collagen is solely found in animal sources. Typically the way to consume it through food is to consume more parts of the animal, such as the cartilage, bone marrow, tendon and gristle when eating meat.
This can be off-putting for some. It also adds in the variable that you are less able to measure the amount you are having, making it more difficult to ensure you are consuming enough to meet your needs.
In some cultures, this is more of a natural occurrence. For example, some Japanese dishes include tendons or chicken feet, which are high in collagen. It is rarer in western cultures though.
Bone Broth vs Hydrolysed Collagen or Gelatin
The other option to meet collagen needs through food is to consume bone broth.
The jelly-like substance that forms at the top of bone broth is gelatin. It is extracted through boiling for those who want gelatin by itself.
Then to convert gelatin to hydrolysed collagen, some chemical reactions are required to cut it in certain places. The only difference is that it no longer forms a gel, which makes it easier to drink, and more appealing for some.
Theoretically, you can skip all that and go straight to the source, which is bone broth.
When I was studying at the AIS in 2017, this was actually looking like a promising option.
Unfortunately in 2019, a study came out that indicated that bone broth is typically not a reliable source of collagen precursors. This is because the dosage is too inconsistent and often too low, in comparison to what has been shown to be effective in the research.
So bone broth can be added to the list of ways to consume collagen precursors through food, but it likely isn’t as effective as directly supplementing the relevant amount of hydrolysed collagen or gelatin.
Vegans and Vegetarians
Unfortunately, there are no vegan and vegetarian sources of collagen.
Collagen comes from things such as skin, bones and tendons typically and it HAS to come from animal products. Because of this, there is no such thing as vegetarian gelatin.
It is possible to make gels using vegan products, but they are made with agar which is a sugar that contains no amino acids. This agar is often used as a placebo in studies.
From an athletic perspective, it is generally possible to match a vegan or vegetarian diet to meet all the same needs that an omnivorous diet does. Initially I saw this as a rare case where that might not be possible.
An idea that could solve this dilemma is that you could supplement the individual amino acids that collagen is high in (proline, glycine, lysine and arginine) alongside vitamin C and get similar results. This has not been studied and I have not heard of many plant-based athletes doing this, but it is something that theoretically should work.
Collagen Supplements and Muscle Growth
Although collagen supplementation appears to be great for collagen synthesis, it is likely awful for muscle growth in comparison to other protein sources.
Collagen peptides have been shown to be poor for stimulating muscle protein synthesis in comparison to whey protein. And while whey protein is typically the gold standard for promoting muscle protein synthesis, there are plenty of other options that promote it to a similar level.
It is worth noting that solely focusing on muscle protein synthesis can be misleading, under rare circumstances. Some people make the argument that collagen could be beneficial for muscle growth due to other factors, such as improving the growth of muscle fascia.
I am yet to see compelling evidence that it is really contributing to muscle growth in a meaningful way that cannot be achieved better by alternatives. At this stage, I wouldn’t recommend taking collagen under the impression that it will help noticeably with muscle growth.
While injured tendons and ligaments have gotten most of the attention in the research so far, there is also a case to be made for injury prevention.
For example, bones contain a large percentage of collagen as well. So theoretically, collagen supplementation prior to any exercise involving jarring impulses (e.g. jumping) that could stimulate bone remodelling, could potentially reduce the risk of fractures.
Collagen supplementation could also help reduce the risk of tendon and ligament injuries too. But this is mostly theoretical, so I wouldn’t read too much into this hypothesis yet.
Further Areas of Research
There are a lot of areas for future research. Personally, I see it as one of the newer areas of nutrition research that could have an impact on the sporting world. I’m excited to be up to date with it right from the start.
For starters, the comparison between whey protein and collagen supplementation in terms of the impact on collagen synthesis rates will be interesting. I’m under the impression that collagen supplementation will be superior for that, but it will be great to see the research when it comes out to either confirm my assumptions or adjust my thinking around the topic.
The other area of interest is the impact on strength and athletic performance in general.
One concept people have discussed is that there are plenty of cases where people improve their strength without increasing their muscle size. There are a lot of factors in this, but one potential factor is that increased tendon strength could be a factor. Theoretically, collagen supplementation could lead to stronger tendons, thereby increasing performance.
In terms of athletic performance, my understanding is that there is currently some research being conducted on markers of athletic performance based on more explosive movements such as sprinting and jumping. And rumour has it that there have been positive results so far, but the research is not yet ready to be published, so it is another ‘watch this space’ area. As of 2021, there is currently one study on that topic – and that study has shown positive outcomes.