Collagen: A Complete Beginner’s Guide
Medically Reviewed by Anthony Dugarte, MD
Published on July 14, 2021
While taking supplemental collagen is undeniably popular, many people aren’t certain what it is or how it may be helpful. Understanding what collagen is and what it does for the body can help you decide if adding it to your routine is right for you.


For the last few years, collagen has been a hot topic in the supplement world.
You’ve heard it’s great for skin and that you can get it from bone broth, but you still have questions. Is it safe? How does it work? And what exactly is collagen anyway?
This article will answer these questions and more to help you decide if getting extra collagen from food or supplements might be helpful for you.
What Is Collagen?
From a culinary point of view, if you’ve ever simmered a chicken or turkey carcass for hours and then cooled the resulting broth, the jelly-like substance that solidifies is collagen.
It is a protein product that can be extracted from the skin, bones, and cartilage of animals in a slow-cooking process.
More scientifically, collagen is the umbrella name for several proteins that provide the connective structure in human and animal tissues. (1)
It is abundantly found in our bones, muscles, skin, ligaments, tendons, cartilage, and joints. Collagen is responsible for giving these tissues their strength and ability to withstand wear and tear.
Collagen is the most abundant protein found in animals, including humans, and it’s not found in plants. All collagen products on the market are derived from the connective tissues of animals. (2)
While work is being done to create vegan sources of collagen in the lab using microbes, most vegan supplemental products are collagen “boosters,” which contain similar amino acids and vitamins from vegan sources. (3)
There are about 28 different types of collagen proteins that have been identified. (2)
The proteins are similar in structure but are mixed with different substances to make different tissues. For example, collagen fibrils found in bones are also structured with calcium.
By far, the three most abundant types of collagen in the human body are:
Collagen Type | Role |
---|---|
Type I | Structure in bone, skin, tendons, ligaments |
Type II | Structure of cartilage, providing cushioning between bones, frame of nose, and ears |
Type III | Structure in muscles, vessel walls, muscles, lung fibers, liver, other organs |
The Difference Between Collagen and Other Proteins
There are many other protein supplements on the market, like whey and branch chain amino acids, and you may wonder what makes collagen different from the others.
To begin with, all protein molecules are created in a unique pattern and ratio of amino acid building blocks.
One outstanding characteristic of collagen is that it’s particularly high in the amino acid glycine, making up about 33% of the protein. In comparison, whey protein only contains about 1% glycine. (4)
Differences in the amino acid ratio may be why collagen protein seems to work better than other proteins for rebuilding and maintaining the structural collagen in our bodies.
Collagen proteins are also high in the non-essential amino acid proline and its derivative, hydroxyproline.
Glycine and proline are considered non-essential amino acids, which means that the human body can make them without getting them directly from the diet.
However, sometimes we need more than our bodies can make, so it’s helpful to get extra building blocks in our diets.
Collagen is also known as an incomplete protein, meaning it doesn’t contain all the amino acids that humans need to eat to maintain health. That means it shouldn’t be used as the only source of protein in our diets.
How Our Bodies Create and Nourish Collagen
Collagen is plentiful in young bodies and is a major part of what keeps us looking and feeling youthful. (5)
Collagen is made by cells called fibroblasts that live within collagen tissues. Scientists are still learning about fibroblasts and how they are nourished to create new collagen.
Most of the collagen in our bodies lack blood vessels which complicates how nutrients reach the fibroblasts. That’s why injuries in connective tissues like tendons and ligaments take longer to heal than muscle injuries.
It is believed that fibroblasts in ligaments and tendons are replenished by nutrients through their surrounding fluids. Nourishment is achieved during exercise, moving fluid in and out of the tissues as they stretch and relax.
It’s now thought that exercise increases collagen production in tendons and ligaments, especially heavy-load exercises.
A small study of eight healthy, active men showed that collagen protein synthesis increased after just 6 sets of knee extensor exercise. (6)
Another study showed that intermittent strength training of 10 minutes of activity with 6 hours of rest resulted in maximum collagen regeneration. (7)
And a study in 2016 showed that athletes who were given 15 grams of collagen gelatin 1 hour before exercise had higher blood indicators of new collagen formation than athletes who took a placebo. (8)
How Collagen Can be Damaged or Depleted
While we lose the ability to make collagen as we get older, environmental factors can also play heavy roles in collagen damage and can slow collagen regeneration.
Damaging ultraviolet light from the sun both degrades the collagen matrix and decreases the skin’s ability to make more collagen. (9)
To avoid this, it’s best to use sun protection like clothing and sunscreens.
Smoking and alcohol use can also contribute to decreased collagen production. Smoking causes free radicals to get in the way of collagen synthesis. (10)
Excessive alcohol use can deplete vitamins and decrease the body’s ability to make new fibroblasts, the cells which make new collagen.
Elevated blood sugar levels decrease the body’s ability to repair collagen. Avoiding processed sugar can help maintain collagen in the skin, blood vessels, kidneys, eyes, and muscles. (11)
Food Sources that Contain Collagen
Foods that contain collagen are animal-based. Collagen is found in the same parts of animals as humans, including skin, bones, and cartilage.
Some popular food sources that contain collagen are:
- Tougher cuts of red meats like pot roast or brisket, which must be cooked for a long time to break down the collagen. Be aware that too much red meat is not recommended in a healthy diet.
- Bone broths, or the liquid from simmering bones for 12–24 hours.
- Fish with bones and skins included canned salmon and sardines.
- Gelatin found in the baking aisle.
Gelatin desserts, jams, jellies, and some gummy candies are also made from collagen but are very high in sugar, making them less optimal choices.
While there may be some microbe-derived vegan sources of collagen on the market, they are hard to find.
Alternatively, the amino acids glycine and proline can be found in many vegan sources.
These foods include soybeans, black beans, kidney beans, other legumes, pumpkin seeds, sunflower seeds, chia seeds, pistachios, peanuts, cashews, cabbage, asparagus, mushrooms, and seaweed.
There are other foods that are not directly derived from the collagen of animals but are rich in the amino acids found in collagen. These foods include eggs, fish, poultry, and dairy.
Nutrients That Boost Collagen Production
Vitamin C, zinc, and copper are essential nutrients that are important for collagen formation.
Essential means that the body cannot make them on its own, and we need to get them in our diets.
The importance of vitamin C during collagen formation is well known. With a severe vitamin C deficiency, humans develop a disease called scurvy, in which collagen fibrils cannot be formed. (12)
This leads to spontaneous bleeding, pain in limbs, ulceration of gums, and loss of teeth.
Excellent sources of vitamin C include bell peppers, broccoli, strawberries, pineapple, and oranges.
Zinc deficiency is known to decrease the body’s ability to make new collagen and break down old cells, so it’s important to get plenty in your diet. (13)
Great sources of zinc include pumpkin seeds, lentils, garbanzo beans, cashews, poultry, and beef.
Copper is needed to reinforce the structure of newly formed collagen fibers. (14)
Foods that are high in copper include cashews, sesame seeds, soybeans, shitake mushrooms, garbanzo beans, lentils, and walnuts.
Forms of Collagen Supplementation
In the supplement world, the marketing of products often gets ahead of the science behind the supplements.
Some studies support the benefits of collagen supplementation but keep in mind that there are still many unknowns regarding how effective it is and what the right doses are for individuals.
Because supplements are not regulated by any government health organization, it’s always best to choose those that have been third-party tested by a private company for purity and quality. Look for a seal from USP, NSF, or Consumer Labs.
Three common forms of collagen supplements are gelatin, hydrolyzed collagen powder, and pills or capsules.
Dosing recommendations according to package directions vary greatly from brand to brand and product to product.
The oldest and most familiar way people supplement collagen is with gelatin, which is sold in grocery store baking isles as a food ingredient and is generally regarded as safe (GRAS) by the Food and Drug Administration.
Gelatin has been consumed by humans for centuries, used as a thickener in foods like jellies, jams, and gelatin desserts. Gelatin is tasteless and can be mixed into foods like soup, drinks, and smoothies.
Hydrolyzed collagen powder, also known as collagen peptides or collagen hydrolysate, is simply collagen that has been chemically broken down from its gelatin form.
This makes the product easier to dissolve in both hot and cold liquids. It is also tasteless and can be mixed into foods and drinks.
Many studies mentioned above used hydrolyzed collagen because it’s considered more palatable than gelatin, and it may be easier to digest and absorb. (15)
Other hydrolyzed collagen supplements come in the form of pills or capsules.
While pill form may appeal to consumers, the pills are usually large and may be hard for some people to swallow. In addition, many of the product labels instruct consumers to take several pills during the day.
Possible Benefits of Collagen Supplements
Collagen has many potential health benefits that have been evaluated in preliminary research.
Keep in mind that the research supporting supplemental collagen’s abilities is in its very beginning stages. While some studies like those below show promise, more robust studies are needed to solidify the evidence.
In addition, different researchers use different forms of supplementation, which makes dosage recommendations difficult for health care professionals.
Research shows that collagen may be able to help with the following conditions:
Joint Discomfort for Healthy Athletes
This is a big area of study, and collagen’s potential for helping athletes remain injury-free is great news.
A 24-week double-blind study involving 97 young athletes with joint pain but no evidence of joint disease were regularly treated with 10 g of collagen hydrolysate. (16)
The treatment group showed significant improvements in pain reduction and increased mobility compared to the placebo group.
Osteoporosis and Osteoarthritis
Current treatments for these diseases are not perfect, and there is a need for new solutions.
A review of nine studies showed that collagen hydrolysate improved the symptoms of osteoporosis and osteoarthritis. (17)
The authors concluded that more studies are needed to determine the most appropriate dosing.
Skin Appearance and Strength
As a nutritionist, I’m always looking for foods that can improve skin from within. Collagen is showing promise.
A review of eight studies with a combined 805 participants concluded that collagen supplementation shows promise in improving wound healing, dermal collagen density, skin elasticity, and hydration. (18)
Again, the authors recommended more studies to determine the most effective dosage.
Fingernail Strength
Weak, brittle nails are a problem for a lot of people. A study involving 25 people who took 2.5 grams of collagen peptides daily for 24 weeks showed an increase in growth velocity and strength in their fingernails. (19)
Age-Related Sarcopenia
Even the healthiest people struggle with muscle loss as they mature. Collagen may be a way to help.
In a study involving patients with age-related muscle loss, or sarcopenia, those who took 15 grams of collagen peptides after guided resistance training showed more muscle gain compared to a placebo group. (20)
Cardiovascular Health
Maintaining healthy arteries and normal cholesterol levels are two ways to ward off heart disease.
A study involving 31 adults showed that taking 16 grams of collagen daily for six months improved artery stiffness and increased “good” or HDL cholesterol. (21)
Safety of Collagen Supplementation
It’s always a good idea to talk to your doctor before beginning a supplement routine to make sure it’s right for you.
Depending on the reason you’re considering collagen, your doctor may find it appropriate to evaluate your health or recommend more appropriate treatments.
Collagen in the form of gelatin that you can find in the grocery store baking aisle is generally regarded as safe (GRAS) by the Food and Drug Administration. (22)
It has been used as an ingredient in foods for centuries, and using it as a supplement should be safe within reason.
The supplemental forms of hydrolyzed collagen have been on the market for far less time, so there is limited safety information, especially because dosing recommendations vary greatly.
Currently, hydrolyzed collagen supplementation seems to be low risk.
A review in 2019 of eight studies involving 680 people showed no adverse effects of collagen during the studies. The length of the studies varied from 56 to 180 days. (18)
The Bottom Line
Collagen is the protein that is responsible for structural tissues in our bodies. Science is working to uncover the best ways to keep our collagen youthful and healthy.
Adequate nutrition, exercise, and avoiding sun exposure and smoking are ways to help keep your collagen structure strong.
We still have a lot to learn about collagen supplementation efficacy, timing, and dosing.
Some research shows promise that collagen supplementation can alleviate common problems like joint health, bone strength, and loss of muscle mass.
While collagen supplementation seems to be low risk in reasonable quantities, it’s always best to talk to your doctor before beginning any new medication or supplement to make sure it’s right for you.
At WellnessVerge, we only use reputable sources, including peer-reviewed medical journals and well-respected academic institutions.
- COLLAGEN STRUCTURE AND STABILITY:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2846778/ - Collagen: The Fibrous Proteins of the Matrix:
https://www.ncbi.nlm.nih.gov/books/NBK21582/ - Recombinant microbial systems for the production of human collagen and gelatin:
https://link.springer.com/article/10.1007/s00253-005-0180-x - High glycine concentration increases collagen synthesis by articular chondrocytes in vitro: acute glycine deficiency could be an important cause of osteoarthritis:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6153947/ - Oxidative Stress in Aging Human Skin:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4496685/ - Myofibrillar and collagen protein synthesis in human skeletal muscle in young men after maximal shortening and lengthening contractions:
https://journals.physiology.org/doi/full/10.1152/ajpendo.00387.2004 - Optimizing an intermittent stretch paradigm using ERK1/2 phosphorylation results in increased collagen synthesis in engineered ligaments:
https://pubmed.ncbi.nlm.nih.gov/21902469/ - Vitamin C–enriched gelatin supplementation before intermittent activity augments collagen synthesis:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5183725/ - Decreased Collagen Production in Chronologically Aged Skin:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1606623/ - Impact of Smoking and Alcohol Use on Facial Aging in Women: Results of a Large Multinational, Multiracial, Cross-sectional Survey:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6715121/ - The role of collagen crosslinks in ageing and diabetes - the good, the bad, and the ugly:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4241420/ - Scurvy Reemergence of nutritional deficiencies:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2567249/ - Zinc may increase bone formation through stimulating cell proliferation, alkaline phosphatase activity and collagen synthesis in osteoblastic MC3T3-E1 cells:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2981717/ - Copper and the synthesis of elastin and collagen:
https://pubmed.ncbi.nlm.nih.gov/6110524/ - Hydrolyzed Collagen—Sources and Applications:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6891674/ - 24-Week study on the use of collagen hydrolysate as a dietary supplement in athletes with activity-related joint pain:
https://pubmed.ncbi.nlm.nih.gov/18416885/ - Collagen supplementation as a complementary therapy for the prevention and treatment of osteoporosis and osteoarthritis: a systematic review:
https://www.scielo.br/j/rbgg/a/fk95TfhxB7mPsmqYRDdHH8K/?format=pdf&lang=en - Oral Collagen Supplementation: A Systematic Review of Dermatological Applications:
https://pubmed.ncbi.nlm.nih.gov/30681787/ - Oral supplementation with specific bioactive collagen peptides improves nail growth and reduces symptoms of brittle nails:
https://pubmed.ncbi.nlm.nih.gov/28786550/ - Collagen peptide supplementation in combination with resistance training improves body composition and increases muscle strength in elderly sarcopenic men: a randomised controlled trial:
https://pubmed.ncbi.nlm.nih.gov/26353786/ - Effect of Collagen Tripeptide on Atherosclerosis in Healthy Humans:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5429168/ - Select Committee on GRAS Substances (SCOGS) Opinion: Gelatin:
https://wayback.archive-it.org/7993/20171031062708/https://www.fda.gov/Food/IngredientsPackagingLabeling/GRAS/SCOGS/ucm261307.htm