July 19, 2017


Collagen supplements have captured the limelight for their many purported health benefits, everything from healthier skin and hair to anti-aging and gut health. Does the research live up to the hype though? Let’s dig a little deeper and find out!


First off, what exactly is collagen? Collagen is the chief structural protein that holds our bodies together. It provides resilient elasticity to our skin, hair, ligaments, and tendons, as well as strength and structure to our bones and cartilage. Collagen is made up of many amino acids, primarily glycine, proline, alanine, hydroxyproline, and glutamic acid. Hydrolyzed collagen and collagen peptides are simply smaller pieces of collagen which are easier to digest.

Collagen, like other proteins, is broken down into amino acids through enzymatic action in the small intestine. These amino acids then enter the blood stream via the the liver. Any amino acids the liver does not need are released into the bloodstream for use by the rest of the body. It doesn’t matter if you’re consuming straight collagen (gelatin) or hydrolyzed collagen (collagen peptides) – both break down into amino acids, the basic building blocks of all proteins.

Why does this matter? Well, it’s not like globs of collagen are floating around your bloodstream patching holes in your gut lining or lifting your under-eye bags. Your cells must instead construct collagen from available amino acids with the help of vitamin C. However, it makes sense that by consuming digestible collagen, you’re providing your body with the necessary amino acids to build and restore collagen-based tissues (skin, hair, ligaments, tendons, bones, cartilage).

Now, let’s review the evidence behind a few of the more popular collagen claims!


Claim: Collagen supplementation improves health of skin, hair and nails.

Consensus: Yes, and maybe. Double-blind, placebo-controlled studies indicate that collagen supplementation can significantly improve skin elasticity and moisture, even reduce wrinkles!1-3 Hoping for more lustrous locks? A recent study in mice showed that collagen destruction is the chief culprit causing age-related hair loss, but more studies are needed to warrant collagen supplementation for hair growth.4 Evidence is currently lacking on collagen supplementation for growing stronger nails,5 so you’re better off protecting your nails with a hardening clear coat and supplementing with biotin instead.


Claim: Collagen supplementation reduces the appearance of cellulite.

Consensus: This actually has some truth! A recent study showed that long-term supplementation (over 6 months) with bioactive collagen peptides significantly improved the appearance of cellulite in women of healthy bodyweight (and to a lesser extent in overweight women).6 It should be noted that collagen creams are not effective, simply because the molecules are too large to be absorbed by the skin.


Claim: Collagen supplementation maintains lean muscle mass and a healthy body weight.

Consensus: Yes… in conjunction with a healthy diet and exercise. High-protein diets reign supreme when it comes to maintaining and building lean mass. The more muscle you have, the more calories you burn, which makes weight maintenance and fat loss that much easier. High-protein diets also help suppress appetite, which means you’re less likely to cheat!

Being a protein, collagen contributes to total protein intake, and has been proven helpful for maintaining lean muscle mass, particularly in the elderly.7,8 In fact, collagen peptides may even be more effective for suppressing appetite than some other protein supplements (whey, casein, soy) according to one recent study.9 The only drawback is that collagen is not particularly high in leucine, which is the rate limiting factor for protein synthesis of muscle tissue. So, don’t rely on collagen for all of your daily protein needs – choose a variety of quality protein sources.


Claim: Collagen supplementation improves joint health.

Consensus: Yes! Current research shows that collagen supplementation is helpful for treating join pain and stiffness, osteoarthritis (joint degeneration due to wear and tear of cartilage), and rheumatoid arthritis.10-13


Claim: Collagen supplementation strengthens bones and teeth.

Consensus: This is only partially confirmed. Collagen peptides are known to stimulate the growth of “osteoblasts,” which are the cells responsible for bone formation.14 Preliminary studies in rats also indicate that collagen supplementation may also help increase bone mineral density.15

Since our teeth and gums are made of collagen, it’s believable that collagen supplementation could help strengthen periodontal structures and even improve periodontitis. However, evidence is lacking here.


Claim: Collagen supplementation heals leaky gut.

Consensus: Maybe. Key amino acids found in collagen do appear to have some benefits for gut health. The amino acids glycine and proline have been shown effective for preventing and treating ulcers, at least in rat studies.16-17 Glutamic acid, more commonly known as glutamine, also seems to help prevent gut inflammation and reduce the oxidative stress thought to cause leaky gut.18 Scientists have further linked low collagen levels to inflammatory bowel disease.19 While collagen supplements may or may not heal your gut, they certainly won’t hurt it. It should be noted that these beneficial amino acids are present in other foods besides collagen.


Claim: Collagen supplementation protects cardiovascular and liver health.

Consensus: Probably not. Available studies show benefits of specific amino acids in collagen, not collagen itself. For example, collagen contains the amino acids arginine and glycine, both of which are suggested agents for liver detoxification,20,21 but again, these amino acids are present in many foods besides collagen.

Proline, another amino found in collagen, has been used as an “alternative” treatment for atherosclerosis (hardening of the arteries), but has not been implemented into mainstream medicine.22 Proline has also been studied for lowering blood pressure with some positive but inconsistent findings.23


So, are collagen supplements worth the investment? Well, they are at least somewhat effective for improving skin elasticity, reducing wrinkles, minimizing the appearance of cellulite, and suppressing appetite. Research also supports their use for reducing joint pain, stiffness, and degeneration. However, the evidence is not-so-convincing for collagen supplements when it comes to treating hair loss, brittle nails, osteoporosis, periodontitis, gastrointestinal disorders, heart disease, or liver disease.

A little bit of collagen goes a long way! For the benefits listed above, 10-12 grams of collagen peptides per day is plenty. I personally use LIV Body Marine Collagen (use discount code “NOEXCUSESCHICK” for 20% off your order). The rest of your protein should come from quality sources such as grass-fed beef, free-range poultry and eggs, lean pork raised without hormones, wild-caught salmon, and other low-mercury fish and seafood. For vegans, choose minimally-processed soy products, beans, peas, lentils, and whole grains.

If you have any questions, feel free to comment below.

No part of this article may be reproduced, copied, modified or adapted, without written permission from Sarah Wilkins. Violation is subject to prosecution by copyright law, and punishable by up to 5 years in Federal prison and a fine up to $250,000.


  1. Proksch, E., Segger, D., Degwert, J., Schunck, M., Zague, V., & Oesser, S. (2014). Oral Supplementation of Specific Collagen Peptides Has Beneficial Effects on Human Skin Physiology: A Double-Blind, Placebo-Controlled Study. Skin Pharmacology and Physiology, 27(1), 47-55. doi:10.1159/000351376
  2. Asserin, J., Lati, E., Shioya, T., & Prawitt, J. (2015). The effect of oral collagen peptide supplementation on skin moisture and the dermal collagen network: evidence from anex vivomodel and randomized, placebo-controlled clinical trials. Journal of Cosmetic Dermatology, 14(4), 291-301. doi:10.1111/jocd.12174
  3. Proksch, E., Schunck, M., Zague, V., Segger, D., Degwert, J., & Oesser, S. (2014). Oral Intake of Specific Bioactive Collagen Peptides Reduces Skin Wrinkles and Increases Dermal Matrix Synthesis. Skin Pharmacology and Physiology, 27(3), 113-119. doi:10.1159/000355523
  4. Matsumura, H., Mohri, Y., Binh, N. T., Morinaga, H., Fukuda, M., Ito, M., . . . Nishimura, E. K. (2016). Hair follicle aging is driven by transepidermal elimination of stem cells via COL17A1 proteolysis. Science, 351(6273). doi:10.1126/science.aad4395
  5. De, D., & Seshadri, D. (2012). Nails in nutritional deficiencies. Indian Journal of Dermatology, Venereology, and Leprology, 78(3), 237. doi:10.4103/0378-6323.95437
  6. Schunck, M., Zague, V., Oesser, S., & Proksch, E. (2015). Dietary Supplementation with Specific Collagen Peptides Has a Body Mass Index-Dependent Beneficial Effect on Cellulite Morphology. Journal of Medicinal Food, 18(12), 1340-1348. doi:10.1089/jmf.2015.0022
  7. Hays, N. P., Kim, H., Wells, A. M., Kajkenova, O., & Evans, W. J. (2009). Effects of Whey and Fortified Collagen Hydrolysate Protein Supplements on Nitrogen Balance and Body Composition in Older Women. Journal of the American Dietetic Association, 109(6), 1082-1087. doi:10.1016/j.jada.2009.03.003
  8. Zdzieblik, D., Oesser, S., Baumstark, M. W., Gollhofer, A., & König, D. (2015). Collagen peptide supplementation in combination with resistance training improves body composition and increases muscle strength in elderly sarcopenic men: a randomised controlled trial. British Journal of Nutrition, 114(08), 1237-1245. doi:10.1017/s0007114515002810
  9. Veldhorst, M. A., Nieuwenhuizen, A. G., Hochstenbach-Waelen, A., Westerterp, K. R., Engelen, M. P., Brummer, R. M., . . . Westerterp-Plantenga, M. S. (2009). A breakfast with alpha-lactalbumin, gelatin, or gelatin TRP lowers energy intake at lunch compared with a breakfast with casein, soy, whey, or whey-GMP. Clinical Nutrition, 28(2), 147-155. doi:10.1016/j.clnu.2008.12.003
  10. Clark, K. L., Sebastianelli, W., Flechsenhar, K. R., Aukermann, D. F., Meza, F., Millard, R. L., . . . Albert, A. (2008). 24-Week study on the use of collagen hydrolysate as a dietary supplement in athletes with activity-related joint pain. Current Medical Research and Opinion, 24(5), 1485-1496. doi:10.1185/030079908×291967
  11. Bruyère, O., Zegels, B., Leonori, L., Rabenda, V., Janssen, A., Bourges, C., & Reginster, J. (2012). Effect of collagen hydrolysate in articular pain: A 6-month randomized, double-blind, placebo controlled study. Complementary Therapies in Medicine, 20(3), 124-130. doi:10.1016/j.ctim.2011.12.007
  12. Bello, A. E., & Oesser, S. (2006). Collagen hydrolysate for the treatment of osteoarthritis and other joint disorders:a review of the literature. Current Medical Research and Opinion, 22(11), 2221-2232. doi:10.1185/030079906×148373
  13. Crowley, D. C., Lau, F. C., Sharma, P., Evans, M., Guthrie, N., Bagchi, M., . . . Raychaudhuri, S. P. (2009). Safety and efficacy of undenatured type II collagen in the treatment of osteoarthritis of the knee: a clinical trial. International Journal of Medical Sciences, 312-321. doi:10.7150/ijms.6.312
  14. Liu, J., Zhang, B., Song, S., Ma, M., Si, S., Wang, Y., . . . Guo, Y. (2014). Bovine Collagen Peptides Compounds Promote the Proliferation and Differentiation of MC3T3-E1 Pre-Osteoblasts. PLoS ONE, 9(6). doi:10.1371/journal.pone.0099920
  15. Porfírio, E., & Fanaro, G. B. (2016). Collagen supplementation as a complementary therapy for the prevention and treatment of osteoporosis and osteoarthritis: a systematic review. Revista Brasileira de Geriatria e Gerontologia, 19(1), 153-164. doi:10.1590/1809-9823.2016.14145
  16. Tariq, M., & Al Moutaery, A. R. (1997). Studies on the antisecretory, gastric anti-ulcer and cytoprotective properties of glycine. Res Commun Mol Pathol Pharmacol, 97(2), 185-198.
  17. Backing, C. (2006, August 22). “Gelatin Treats Ulcers.” Medical News Today. Retrieved from
  18. Lin, M., Zhang, B., Yu, C., Li, J., Zhang, L., Sun, H., . . . Zhou, G. (2014). L-Glutamate Supplementation Improves Small Intestinal Architecture and Enhances the Expressions of Jejunal Mucosa Amino Acid Receptors and Transporters in Weaning Piglets. PLoS ONE, 9(11). doi:10.1371/journal.pone.0111950
  19. Koutroubakis, I. E. (2003). Serum laminin and collagen IV in inflammatory bowel disease. Journal of Clinical Pathology, 56(11), 817-820. doi:10.1136/jcp.56.11.817
  20. What is Collagen? 7 Ways Collagen Can Boost Your Health. (2017, March 28). Retrieved May 01, 2017, from
  21. Vital Proteins. (2014, March 31). Liver Health. Retrieved May 01, 2017, from
  22. The Collagen Connection. (2013, April 19). Retrieved May 1, 2017, from
  23. Cicero, A. F., Aubin, F., Azais-Braesco, V., & Borghi, C. (2013). Do the Lactotripeptides Isoleucine-Proline-Proline and Valine-Proline-Proline Reduce Systolic Blood Pressure in European Subjects? A Meta-Analysis of Randomized Controlled Trials. American Journal of Hypertension, 26(3), 442-449. doi:10.1093/ajh/hps044


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