Kourtney Kardashian says we should all be taking collagen supplements, but what does science say?

Updated: Jul 11, 2020

*Disclaimer: I am not a registered dietitian, naturopath, doctor, or other type of healthcare professional. This is simply the product of my own research and opinions, not to be used to replace the recommendations of a registered healthcare professional.


If you’ve been on the internet lately, you have probably heard about the exponentially growing buzz around collagen supplements. In today’s day and age, according to those who support the movement, if you aren’t taking a collagen supplement, you’re on a slippery slope towards becoming weak, brittle and wrinkly. Personally, I care about my health a great deal, but I’m not sure if I need to spend over $60 on Kourtney’s ~collagen vibes~ to get there. So, the question left is: should we all be taking collagen supplements?



So, before we talk about whether collagen supplements work or not, we must first discuss what collagen actually is. If we’re trying to figure out whether we should be taking collagen supplements, we should at least know what collagen is made of, how it’s synthesized; and what it’s used for in the body. To begin, collagen is a protein that makes up approximately 30% of your body’s protein composition. It’s a major structural component of the connective tissue that helps make up your skin, muscles, bones, tendons, ligaments, cartilage, blood vessels and even teeth. There are 4 main types of collagen, however supplements generally only include types I-III:

- Type I: makes up about 90% of the body’s total collagen and is made up of densely packed fibers providing structure to the skin, bones, tendons, fibrous cartilage and teeth

- Type II: found in the elastic cartilage that cushions joints

- Type III: supports structure of muscles, organs and arteries

As we age, our collagen producing cells produce less and lower quality collagen. This reduction primarily occurs in collagen types I and III, resulting in more loosely packed collagen fibers and giving the appearance of wrinkled, saggy skin. Thus, the hopes with a collagen supplement is to try and prevent or correct the visible effects of aging by providing the necessary components for increased collagen synthesis.


Collagen is primarily composed of three main amino acids (building blocks of proteins): glycine, proline and hydroxyproline (a derivative of proline). The hydroxylation of proline (to make hydroxyproline) requires the cofactors oxygen, iron and vitamin C. Cofactors are the extra things that need to be added to the reaction to make the metabolic reaction possible. Typically, collagen supplements are sold “hydrolyzed”, meaning that the collagen protein is broken down into its amino acid components, so that they can be easily absorbed by the body.



Now, let’s get into some of the scientific literature. One of the biggest challenges associated with determining the efficacy of collagen supplements is the fact that most studies are funded by the supplement companies themselves. However, there are still quite a few studies without external funding that support the use of collagen peptides (with vitamin C) for improving skin elasticity, hydration and the appearance of wrinkles. In one 2018 study, they found that, in women aged 40-60 taking type I collagen supplements for 12 weeks, there was a significant improvement in skin hydration as early as 6 weeks in; and a significant improvement in skin elasticity and the appearance of wrinkles after 12 weeks [1]. It’s believed that the collagen peptides stimulate both the production of hyaluronic acid (HA), improving skin hydration; and the downregulation of matrix metalloproteinases (MMPs), which are responsible for the degradation of collagen and elastin in the skin [1].


Interestingly, another 2018 systematic review found that vitamin C supplementation alone increases the activity of procollagen (precursor to collagen) secreting fibroblasts (which decrease with age) and overall type I collagen production [2]. Thus, it would be interesting to see the previous study repeated with collagen alone, collagen + vitamin C; and vitamin C alone to compare the effects between each component individually as well as in tandem with each other.



Looking at the effects of type II collagen on knee osteoarthritis symptoms, another study found that, in individuals between 40-75 years old, there was a significant reduction in osteoarthritis symptoms relative to the control group at day 180 with no significant change in knee range of motion (ROM) [3]. Although this study was funded by a collagen supplement company, another systematic review agreed that there exists a significant reduction in symptoms when measuring patients with severe osteoarthritis [4]. However, the same review concluded that, overall, there is still not enough evidence to fully establish collagen’s therapeutic effects, as there is still a high degree of heterogeneity between studies [4].

Regarding those who are active and are looking to take a collagen supplement for joint/muscle protection and recovery, a study on varsity athletes showed that 5g of collagen peptides for a 12-week period resulted in significantly reduced joint pain during activity and a significantly reduced need for additional therapies such as physiotherapy and ice packs [5]. However, similar to the study on osteoarthritis patients, there was no significant change in ROM amongst these athletes.


However, in a review on nutrient supplementation of proline (one of the amino acids necessary for collagen synthesis), results showed that there is evidence of a physiological limit to the amount of dietary proline that can be absorbed into the peripheral circulation (the bloodstream) [6]. In this way, the excess proline past this physiological limit is catabolized (broken down) by the proline oxidase in the small intestine. Furthermore, hydroxyproline (another important product to collagen synthesis) is readily broken down upon ingestion; and is only synthesized after proline has been incorporated into the collagen [6]. It’s important to note that this review specifically looked at supplementation for accelerating the wound healing process, however it does shed light on the bioavailability of hydrolyzed collagen peptides.


Overall, there is a growing body of research in support of the use of supplements for improving joint pain and skin appearance. But, it’s important to note that a lot of the research in support of collagen supplements are for people who have a purpose for taking them (i.e. older skin, pre-existing joint pain). There’s really not much research in support of taking collagen supplements as a preventative measure (especially hydrolyzed collagen peptides). Further, it’s important to remember that collagen is a protein; and all proteins are made from the same pool of amino acids (20 of them), 9 of which are considered essential (cannot be made by the body). As long as you’re getting enough of the essential and non-essential amino acids, you can’t really “trick” or “program” your body into making more collagen if it has other priorities. Additionally, if you overconsume amino acids, they get excreted by the body and even stored as fat.



However, with all this being said, there’s still conflicting evidence regarding how well hydrolyzed collagen peptides are absorbed and used by the body. I would argue that we should always opt for real food first because our bodies know exactly how to break it down and make use of it in the most effective way possible. The amino acids necessary for collagen production can be found in animal protein sources and even some in certain plant-based sources (i.e. beans). After all, most collagen supplements come from either bovine (beef) or fish sources – which makes most collagen supplements not vegan, FYI. Further, vitamin C is an important cofactor for collagen production, so making sure to get enough vitamin C through foods like peppers, kale, broccoli, tomatoes, strawberries, oranges and spinach will naturally help increase collagen synthesis. In addition to eating the right collagen boosting foods, it’s also important to avoid things that will degrade your collagen and reduce its synthesis such as smoking and UV radiation. Further, if you are concerned with your skin appearance specifically, making sure you’re getting enough nutrients through a healthy diet, exercising regularly and drinking enough WATER are key for a youthful, glowing complexion.


If you aren’t getting enough protein and are looking to add a collagen supplement to you diet as a way of increasing your protein intake, then I would argue that there’s better protein options out there. Collagen supplements are an incomplete protein, meaning that they do not include all 9 essential amino acids; only the amino acids specific to collagen production. Thus, I think that it’s probably better to opt for a complete protein (like whey protein), or even mix the collagen supplement with a complete protein source if you want to try its alleged effects out for yourself. I personally think it would be really interesting to see a study comparing a collagen supplement to a whey protein powder rather than a placebo to see the extent of the differences between the two (if any) on skin appearance, muscle recovery and joint function. What do you think? Have you noticed a difference taking collagen supplements? Comment your thoughts below!


Works Cited:

[1] Kim, D. U., Chung, H. C., Choi, J., Sakai, Y., & Lee, B. Y. (2018). Oral Intake of Low-Molecular-Weight Collagen Peptide Improves Hydration, Elasticity, and Wrinkling in Human Skin: A Randomized, Double-Blind, Placebo-Controlled Study. Nutrients, 10(7), 826. https://doi.org/10.3390/nu10070826

[2] DePhillipo, N. N., Aman, Z. S., Kennedy, M. I., Begley, J. P., Moatshe, G., & LaPrade, R. F. (2018). Efficacy of Vitamin C Supplementation on Collagen Synthesis and Oxidative Stress After Musculoskeletal Injuries: A Systematic Review. Orthopaedic journal of sports medicine, 6(10), 2325967118804544. https://doi.org/10.1177/2325967118804544

[3] Lugo, J. P., Saiyed, Z. M., & Lane, N. E. (2016). Efficacy and tolerability of an undenatured type II collagen supplement in modulating knee osteoarthritis symptoms: a multicenter randomized, double-blind, placebo-controlled study. Nutrition journal, 15, 14. https://doi.org/10.1186/s12937-016-0130-8

[4] Van Vijven, J. P., Luijsterburg, P. A., Verhagen, A. P., van Osch, G. J., Kloppenburg, M., & Bierma-Zeinstra, S. M. (2012). Symptomatic and chondroprotective treatment with collagen derivatives in osteoarthritis: a systematic review. Osteoarthritis and cartilage, 20(8), 809–821. https://doi.org/10.1016/j.joca.2012.04.008

[5] Zdzieblik, D., Oesser, S., Gollhofer, A., & König, D. (2017). Improvement of activity-related knee joint discomfort following supplementation of specific collagen peptides. Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme, 42(6), 588–595. https://doi.org/10.1139/apnm-2016-0390

[6] Albaugh, V. L., Mukherjee, K., & Barbul, A. (2017). Proline Precursors and Collagen Synthesis: Biochemical Challenges of Nutrient Supplementation and Wound Healing. The Journal of nutrition, 147(11), 2011–2017. https://doi.org/10.3945/jn.117.256404