Recently it seems like everywhere I look people are talking about, and taking, collagen peptides. So let’s talk about what the heck they are and why they have become the newest craze.

The Basics of Collagen

First things first, collagen is one of the most abundant proteins in your body. It's the main protein involved in making connective tissue, but also is part of your muscles, bones, tendons, blood vessels — basically, everything. Since collagen is a protein, this means it’s made up of a bunch of amino acids. More specially, it has high amounts of glycine, proline, and lysine, which account for approximately 50% of its amino acid content. During the synthesis of collagen, proline, and lysine get converted in a vitamin C dependent reaction to make hydroxyproline and hydroxylysine, respectively. Although the levels of BCAAs are somewhat low in the collagen, collagen’s combination of proline, glycine, and lysine make it a great mixture for maintaining nitrogen balance and weight during diet conditions.

Collagen Peptides

Most collagen supplements are collagen peptides. Collagen peptides are made by breaking down the molecular bonds (enzymatic hydrolysis) of collagen strands and turning them into short amino acids chains (peptides). That’s why another name for collagen peptides is "hydrolyzed collagen." Gelatin is pretty similar to collagen peptides but differs in solubility because it is made from the partial hydrolysis of collagen. That’s why peptides can be dissolved in hot or cold substances, but gelatin can only be dissolved in hot liquids. Collagen peptides are highly bioavailable and, combined with their ability to be mixed into nearly anything, they have become super popular.


Why People Have Been Using Them

Since collagen is considered the body’s glue, it’s been most often used for the following purposes:

  1. To improved skin elasticity1 and decrease wrinkles2
  2. To improve digestion3
  3. To improve joint health45
  4. To improved hair and nail strength6
  5. To increase body composition and performance7

With aging, collagen production slows down. That’s why it’s an extremely helpful supplement for skin and joint health. In the context of gut intestinal health, collagen acts to build the tissue that lines the GI tract and colon. Supplementing with collagen can help seal and heal injuries to the digestive tract. In the context of joint health, collagen is beneficial because your joints are made of collagen, thus by taking it, you can ward off joint degeneration. Finally, collagen supplementation has been shown to both improve performance and increase muscle mass (by reducing body fat), when combined with training. For a long time, we knew collagen had benefits as a training supplement, but we weren’t sure why. However, recently new research has shed some light on the topic.

Anabolic Collagen

About a year ago I was in the office of a well-known MD. He asked me if we had any new findings in the lab lately, and I told him we discovered that a protein that regulates collagen production in muscle was regulating muscle size, and that we hypothesized that collagen could make muscles big. When he heard this, his face lit up, he smiled, and he said, “Guess what I’ve been giving my bodybuilders lately.” Well, based on the topic of this article, I’m sure you all guessed collagen. And you are right. It turns out that he was giving the bodybuilders’ collagen peptides and they were getting bigger.

We were all excited about this, so of course, I went back to the lab and directly tested the question, “Does collagen make muscles grow?” by injecting collagen into the muscles of mice on a weekly basis for six weeks. Low and behold, we found out that intramuscular collagen injections were stimulating muscle hypertrophy (please don’t try this on yourself). We were onto something though, as a few papers later came out on the topic of collagen and anabolic muscle growth.

READ: The General Adaptation Syndrome and Its Applications for Training

So what was this evidence to suggest that collagen has anabolic properties8? In 2016, a group showed that the collagen peptidehydroxyprolyl-glycine was capable of causing muscle cells to undergo hypertrophy in an mTOR signaling dependent way9 (mTOR is considered a master regulator of muscle growth, and the thing that myostatin inhibits10). However, the next paper to come out shed more light on how collagen synthesis promoted muscle hypertrophy.

When a muscle gets a hypertrophic response, like the damage from training, muscle stem cells are activated. Activated muscle stem cells can work to repair an injured myofiber, but they can also give rise to myogenic progenitor cells in the extracellular matrix (you know, that collagen-filled matrix that surrounds muscle). Last year, a group of scientists found that muscle progenitor cells interact with collagen-producing cells to facilitate collagen production that is necessary for muscle to respond optimally to hypertrophic stimuli. In fact, they found that collagen synthesis during the first week following a hypertrophic stimulus is sufficient to promote long-term hypertrophy11. This means that when you train, the matrix around your muscle starts making more collagen, and that collagen production is necessary for hypertrophic signaling and muscle growth.

Personal Experience

Anyone who knows me knows I eat like a five-year-old. Most mornings, my days are like so:

  1. Get up and feed and take out the dog.
  2. Get in some cardio (five to seven miles of running, 40 to 60 minutes Stairmaster, etc.).
  3. Get home, take the dog out again, shower, and multitask cleaning, playing with Primo, and getting ready for work.
  4. Realize I’m late, freak out, and rush to work.

Because of the time it takes for numbers three and four to happen, I was skipping breakfast a lot. Then, about two months ago I started drinking Bang energy drinks post-cardio for the caffeine benefits. Two weeks after that, the gym was giving away free collagen samples and I thought, "Damn, I should just throw these in the Bang and get an extra 10 grams of protein for only 35 kcals.” And so I did, and have been doing so for about a month.

The effects? Well for one, it totally blunts my morning hunger. Working in a lab, I struggle to find normal eating times, so I soon also added it to my afternoon coffee or decaf coffee. After about two weeks, I realized I had unintentionally lost weight because the combination was keeping me pretty full. It also blunted my peanut butter cravings. On the strength end of things, I also noticed that I was able to keep increasing my strength, even on days when I was mentally checked out and had dropped weight. So for me, anything that increases relative strength is a plus. Finally, and this is the coolest effect, my scars started healing better. For example, whenever I get a scar, they always fail to disappear. Around the time I started collagen, I was baking cookies, and the cookie sheet (straight of the oven) banged into my chest. This caused a not-so-cute chest scar. Anyways, for the first time, the scar started healing without a keloid. I can’t believe it. So overall, I’ve become a believer in the benefits of collagen peptides.


  1. Borumand, M. & Sibilla, S. Daily consumption of the collagen supplement Pure Gold Collagen(R) reduces visible signs of aging. Clinical interventions in aging 9, 1747-1758 (2014).
  2. Proksch, E. et al. Oral intake of specific bioactive collagen peptides reduces skin wrinkles and increases dermal matrix synthesis. Skin pharmacology and physiology 27, 113-119 (2014).
  3. Koutroubakis, I.E. et al. Serum laminin and collagen IV in inflammatory bowel disease. Journal of clinical pathology 56, 817-820 (2003).
  4. Bello, A.E. & Oesser, S. Collagen hydrolysate for the treatment of osteoarthritis and other joint disorders: a review of the literature. Current medical research and opinion 22, 2221-2232 (2006).
  5. Trentham, D.E. et al. Effects of oral administration of type II collagen on rheumatoid arthritis. Science 261, 1727-1730 (1993).
  6. Chen, P., Cescon, M. & Bonaldo, P. Lack of Collagen VI Promotes Wound-Induced Hair Growth. The Journal of investigative dermatology 135, 2358-2367 (2015).
  7. Zdzieblik, D., Oesser, S., Baumstark, M.W., Gollhofer, A. & Konig, D. Collagen peptide supplementation in combination with resistance training improves body composition and increases muscle strength in elderly sarcopenic men: a randomised controlled trial. The British journal of nutrition 114, 1237-1245 (2015).
  8. Doessing, S. et al. Growth hormone stimulates the collagen synthesis in human tendon and skeletal muscle without affecting myofibrillar protein synthesis. The Journal of physiology 588, 341-351 (2010).
  9. Kitakaze, T. et al. The collagen derived dipeptide hydroxyprolyl-glycine promotes C2C12 myoblast differentiation and myotube hypertrophy. Biochemical and biophysical research communications 478, 1292-1297 (2016).
  10. Trendelenburg, A.U. et al. Myostatin reduces Akt/TORC1/p70S6K signaling, inhibiting myoblast differentiation and myotube size. American journal of physiology. Cell physiology 296, C1258-1270 (2009).
  11. Fry, C.S., Kirby, T.J., Kosmac, K., McCarthy, J.J. & Peterson, C.A. Myogenic Progenitor Cells Control Extracellular Matrix Production by Fibroblasts during Skeletal Muscle Hypertrophy. Cell stem cell 20, 56-69 (2017).