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Are Collagen Supplements Worth It?

Dr. Keith Baar, a lead researcher in the role of collagen supplementation in tendon and ligament health, voiced how collagen’s marketing is in the advanced stages compared to the science being in its early stages. His science-informed response cannot be overlooked.

In this article, I’m going to explain what collagen is and why it may be beneficial for tendon and ligament health.

What Is Collagen?

The collagen protein is a tightly-coiled triple-helix (similar to the double-helix structure of DNA), with a glycine amino acid at every third position on each strand. Thus, glycine makes up 33% of all amino acids in the collagen protein. In science, shape denotes function: Glycine consistently in that third position is what allows the protein to form that tight coil, which, like a rope, provides for a strong structure.

However, collagen is an incomplete protein, meaning it doesn’t contain all nine of the essential amino acids (EAA). Besides glycine, other common amino acids found in collagen include lysine (an EAA), proline, arginine, hydroxyproline, and hydroxylysine.

Where is Collagen Found in the Diet?

Collagen is only found in animals. A high-collagen diet has been equated to a hyena’s diet, or as Dr. Baar referred to as eating everything that exists on an animal, including connective tissue, bones, skin, meat… appetizing.

There are no equal plant-based alternatives, meaning vegetarian and vegan athletes aren’t consuming much (if any) collagen through their diets. Gelatin plant products are made from agar (i.e., sugar), which doesn’t contain the desirable amino acid profile in regards to the proposed benefit for tendon and ligament health.

Animal products = collagen.

The Difference Between Gelatin and Collagen

Much of the research on tendon health is based on gelatin.

Gelatin is a protein derived from the cooking of collagen. Gelatin is insoluble in water, meaning it doesn’t evenly mix into water like a lemonade powder would. Once gelatin is added to water, it begins to clump. The longer gelatin interacts with water, it forms a gel. That’s how Jell-O takes its shape.

When gelatin is processed into smaller peptide chains, it’s called hydrolyzed collagen (HC). Unlike gelatin, HC is soluble in water. Now, that lemonade powder can evenly dissolve and remain dissolved—no clumping.

Throughout the remainder of this article, I’m going to use gelatin and collagen interchangeably, since they differ only in how they interact with water.

Products range from the baking aisle to the powdered supplement world.

What does the Research Say re: Collagen Supplementation for Ligament/Tendon Health?

The current theory is that if we increase our consumption of amino acids that are present in targeted tissues (i.e., consume more glycine for our glycine-rich collagen), we are increasing the likelihood that these amino acids will reach and saturate that targeted tissue.

Let’s walk through four studies.

  • Study design: Case study. Rehabilitation of two male elite rugby players.

  • Was there a control group to compare? No

  • Collagen intervention: Supplementation was consumed 30 minutes before rehabilitation sessions. The treatment included 10 grams gelatin and 250 milligrams vitamin C.

  • Other nutrition interventions: Daily throughout the study, players were advised to consume (1) six servings of high-leucine protein, separated by 2-3 hours, (2) creatine monohydrate (an initial loading phase, then 3 grams daily thereafter), and (3) 2,000 milligrams EPA (an omega-3 fatty acid). Additionally, they were counseled to follow the best practices of nutrition for injury, with daily energy and macronutrient targets having been calculated.

  • Other meaningful study components: The study lasted 30 weeks. Measured outcomes included body composition [change in body weight and lean mass for the whole body and for comparing legs (injured versus uninjured], running speed, degree of knee motion, and predicted 1 RM.

  • Outcome: No measurement of gelatin supplementation was evaluated. The purpose of this study wasn’t to measure the impact of specific supplements or dietary measures, but to design a protocol for post-operative ACL rehabilitation, which included exercise, diet, and supplementation.

  • Study design: Randomized double-blinded cross-over study. Eight recreationally-active males.

  • Was there a control group to compare? Yes.

  • Collagen intervention: Supplementation was consumed 60 minutes before exercise (six minutes of continuous jump rope). There were three treatments that each participant underwent: (1) 15 grams maltodextrin (no gelatin; placebo) + water + Ribena blackcurrant drink “light” version (48 mg vitamin C per 80 mL), (2) 5 grams gelatin + water + Ribena, and (3) 15 grams gelatin + water + Ribena.

  • Other nutrition interventions: There was neither mention of any dietary nor supplemental evaluation.

  • Other meaningful study components: (1) Petri dish evaluation of engineered ligaments, which were infused for a six-day period with blood from baseline (i.e., no gelatin supplementation) and 1-hour post-supplementation (i.e., gelatin-rich blood). Ligaments were evaluated at day 6 for tensile strength and weight. (2) Per treatment, blood work was collected ten times to evaluate PINP, with an increase representing collagen synthesis.

  • Outcome: (1) The petri dish engineered ligament infused with the 1-hour post-supplementation blood (the 15-gram gelatin dose) resulted in greater weight, tensile strength, and had a greater development of collagen compared to the 5-gram dose and placebo. However, all this means is that the benefits found were due to directly infusing nutrients onto a ligament—this is very different from eating. (2) The 15-gram group showed the largest amount of PINP. However, all this means is that collagen synthesis increased somewhere in the body.

  • Study design: Case study. Rehabilitation of one male professional basketball player.

  • Was there a control group to compare? No.

  • Collagen intervention: Supplementation was consumed 60 minutes before exercise (~10 minutes of heavy-loaded mid-range isometric holds of three lower-body exercises). The treatment included 15 grams of gelatin mixed into 16 oz. orange juice (containing 225 milligrams vitamin C).

  • Other nutrition interventions: None. “Normal dietary intake for the player was not tracked, nor did the player report changes in dietary intake over the length of the study.”

  • Other meaningful study components: The study lasted 18 months. MRI scans of the knee were taken at multiple time points (before and during the intervention, plus six months after the intervention ended).

  • Outcome: The patellar tendon was deemed normal through MRI scans reviewed by an orthopedic surgeon who was unaware of the study and that the scans were from someone who previously had patellar tendinopathy. Plus, the athlete reported a reduction in pain and improved performance.

  • Study design: Randomized double-blinded cross-over study. Ten recreationally-active males.

  • Was there a control group to compare? Yes.

  • Collagen intervention: Supplementation was consumed after an overnight fast, 60 minutes before exercise (six minutes of continuous jump rope). There were four groups that each subject participated in: (1) As a liquid: 15 grams gelatin + water + Ribena (45 mg vitamin C). (2) As a liquid: 15 grams HC + water + Ribena. (3) As a gummy: 7.5 grams each of gelatin and HC + water + Ribena. (4) As a liquid (no gelatin/HC; placebo): 15 grams maltodextrin + water + Ribena.

  • Other nutrition interventions: None. Participants self-selected their diet, recorded what they consumed for 12 hours leading up to and during each intervention, and were asked to avoid alcohol 24 hours before each intervention. After having jumped rope, participants ate whatever they wanted.

  • Other meaningful study components: Blood work was collected at baseline and four hours post-jump rope to evaluate PINP.

  • Outcome: No significance was found between the groups, meaning the preparations may not matter. The gummy group showed the least PINP variability.

What is the Current Research NOT Telling Us?

Lack of Understanding Where the Consumed Amino Acids go Once Swallowed

Studies #2 and #4 support that when collagen is consumed, both blood levels of its amino acids and total collagen production are increased—but this doesn’t mean the amino acids are going to the targeted, desirable location within the body and/or that collagen production is increasing at that desirable location. Similar to how body fat spot-reduction workouts are ineffective, as is targeting amino acids to a specific spot—especially when there are no amino acid-tracking studies to clarify a mechanism.

This is very different from study #2 also describing the beneficial outcome of amino acid-rich blood being directly added to an engineered ligament tissue in a petri dish—this is not normal life. Petri dish research, although valuable, completely bypasses the digestive, absorptive, and circulatory mechanisms that naturally occur when we eat. Petri dish research is like spreading peanut butter directly on toast: You’re watching the end stage happen. The process of eating would be like owning a grocery store, hoping that when people buy a jar of peanut butter it will eventually be spread onto toast, in the person’s kitchen, and that they will be satisfied with their lunch.

When we eat or supplement with amino acids, we don't know where in our body those amino acids go and what they do. It's a guessing game.

Lack of Comparison with Other Proteins

As of right now, all we know is that collagen—either compared to a non-protein source or varying doses and textures of collagen itself—may be beneficial for collagen synthesis. However, and the research is currently being evaluated for this, we don’t know if 10-15 grams collagen supplementation is better, no better, or worse than 10-15 grams of a complete protein, like eggs (2 whole) or whey protein isolate powder (1/2-3/4 scoop).

Lack of Comparison of Diet

None of the studies controlled for dietary intake. Athletes eat more than the average human, and therefore tend to have higher protein intakes. Half of the studies discussed weren't even performed on athletes. Were any of the participants vegan? Was anyone on a diet and not consuming adequate protein, with collagen supplementation helping to improve or reduce deficiencies? Was something else in the diet influencing the results? There's no mention of any of this, which is why employing a registered dietitian (and looking for this in the methods' section of a dietary/supplemental intervention study) can be helpful to fairly evaluate and compare outcomes.

Lack of Studies Without a Loading Environment

Research repeatedly has shown the beneficial effects between tendon/ligament health and loading with exercise (e.g., strength training, jump rope), yet the studies reviewed all combined collagen supplementation with loading. Without studies measuring the effect of collagen supplementation on its own, it’s difficult to conclude collagen’s (potentially) additive benefit.

Take-home Messages:

Ultimately, “poor nutrition, genetics, and disease can make connective tissue prone to failure.” Central adiposity increases one’s risk of patellar tendinopathy, so evaluating body composition and a well-planned dietary strategy are also important, well before supplements are discussed.

If I only had one protein supplement to pick for reducing injury risk or its involvement in a post-injury or post-operative plan, it would be whey protein isolate. Plus, for athletes in the post-operative and limb immobilization periods, protein supplementation can help an athlete meet their higher-than-normal daily protein targets. I would not recommend an incomplete protein, like collagen, to fulfill these needs.

However, if you’re doing the nutritional basics right, including high-quality, complete proteins, fruits and vegetables, and avoiding processed/fatty foods, the addition of collagen supplementation shouldn’t be an issue. It just shouldn’t be your starting point.

Full disclosure: I do advise certain professional baseball athletes with whom I work with to supplement with collagen--given they're doing the nutritional basics right. At their level, any harmless intervention to prevent injury risk and improve return-to-play guidelines is worth it.

So, if you’re set on collagen supplementation, here are some considerations:

  • Consume 10-15 grams collagen (potentially more): There is currently no study using a body-weight dependent dose. For taller and/or heavier athletes, you may want to consider a larger dose. Of note: If you're using Knox gelatin from the baking aisle, two powdered packets = 10 grams gelatin.

  • Include vitamin C (maybe): Per the studies, you’re looking at 50-250 milligrams vitamin C, which can be supplemental (e.g., multivitamin) or dietary (8-oz. orange juice = 124 milligrams vitamin C; recommended, since a pre-workout snack should contain carbohydrates). Granted, studies performed after overnight fasts incorporate vitamin C because the body has depleted its stores by the time morning arrives and vitamin C is required for collagen synthesis. If you’re eating fruits and vegetables, taking a multivitamin, and then training in the afternoon, you probably have enough vitamin C on board and can neglect additional supplementation. That said, collagen products tend to contain vitamin C: Klean Athlete Collagen+C contains 60 milligrams whereas Vital Proteins Collagen Peptides contains 90 milligrams.

  • Be wary of Jell-O: To make gelatin-rich Jell-O (I personally think the texture is terrible), you need to boil the liquid, which deactivates vitamin C rendering it relatively useless. Here is a recipe, but I would suggest NOT mixing the vitamin C supplement with the boiling water.

  • Consume 30-60 minutes before consistent, site-specific exercise: Notice how the studies used six minutes of jump rope or 10 minutes of isometric loading. As of right now, you need to combine supplementation with a well-timed site-specific exercise plan.

  • Avoid bone broth: Bone broth as a collagen source is not recommended, since you don’t know how much collagen is in it. You neither have a known nor reliable dose, when studies have been dose-specific.

Further Reading

Learn how to choose a safe, research-based, and effective supplement for your sport.

Depending on the type of injury, supplementation may have a beneficial role for muscle mass.

Episode 109 (February 2019): Collagen Peptides for Injury Prevention & Tissue Repair

Baar, K. (2018). Int J Sport Nutr Exerc Metab,29(4):453-457

Lis, D.M., & Baar, K. (2019). Int J Sport Nutr Exerc Metab,29(5):526-531.

Shaw, G., Lee-Barthel, A., Ross, M.L.R., Wang, B., and Baar, K. (2017). Am J Clin Nutr,105(1):136-143.

Shaw, G., Serpell, B., and Baar, K. (2019). J Sports Sci,37(15):1794-1803.


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