Experts say there are some side effects of drinking collagen that you should know.
7 Surprising Side Effects Of Drinking Collagen That You Need To Know
by Lauren Schumacker and Kelly Glass
Originally Published: 

Scan the shelves and pages of stores both in-person and online and you’ll see it: collagen. It’s in skin creams promising to do away with wrinkles, pills claiming to ease achy joints, and powdered in colorful containers waiting to be consumed. Is it just a health fad, or are the benefits real? Well, if you’re enticed by the thought of putting a spoonful of healthfulness in your coffee, there are some surprising side effects of drinking collagen that you need to know.

First off, collagen is a connective tissue that you naturally produce in your body. It's more difficult to produce enough collagen as you age, however, so some people turn to other sources (like supplements and cosmetic procedures) to get what they're hoping are some of the same effects that they'd get from the collagen their body produced.

"Collagen protein fills a gap in the modern day diet; it is not just a flash in the pan," Pamela Schoenfeld, a registered dietitian and author of The Collagen Diet: Rejuvenate Skin, Strengthen Joints and Feel Younger by Boosting Collagen Intake and Production, tells Romper by email. "You don't have to buy collagen protein in powder form. Foods like bone broth, gelatin desserts and salads, oxtail soup, short ribs, and chicken wings are great sources."

Still, if you're going to use a powdered collagen (or another form of the supplement), which Schoenfeld says can be easiest and most effective, it's a good idea to know what sorts of side effects might come along for the ride.


Collagen Might Help Ease Joint Pain

Achy joints seem to magically occur upon turning 30. What's more is that women are more likely to experience severe joint pain than men, noted the CDC. Pregnancy can also worsen back pain and other inflammatory conditions of the joints, according to the Arthritis Foundation. As baby grows, the increasing weight puts more stress on weight-bearing joints, like the hips, ankles, and knees. A 2017 study in PLoS One concluded that the daily oral consumption of collagen had an anti-inflammatory effect on people with swelling and tenderness in their joints.

Schoenfeld agrees, noting that in her experience, many people who use collagen peptides for about two to four months can see some benefits in terms of joint pain. If the joint pain struggle is real for you, it might help you too.


It Might Help Improve Your Skin — Or Maybe Not

Schoenfeld says many people who regularly consume a collagen supplement might notice improvements in their skin, but there is some doubt. What we do know is that the less collagen in your skin, the less firm your skin is and the more wrinkles and sagging you have to deal with. She also notes that topical collagen treatments can stimulate the production of collagen, but what about ingesting oral collagen? There is some scientific evidence that collagen might help improve skin. For example, a couple of 2014 studies showed that women who took collagen showed an improvement in skin elasticity, while control subjects who took placebos did not. Drinking collagen peptides also resulted in better skin elasticity and hydration after 12 weeks in a study in the journal Nutrients.


It May Help Your Digestive System

Inti St. Clair/Photodisc/Getty Images

Wellness websites across the internet claim collagen is good for gut health, but there’s not a whole lot of scientific information that directly supports this assertion. A 2017 study in the journal Food & Nutrition did conclude that collagen peptides can reduce intestinal barrier dysfunction, a common culprit behind irritable bowel syndrome, inflammatory bowel disease, and metabolic syndrome. As for collagen’s effect on general gut health, there’s more to be desired. However, it's safe to say that collagen's effect on the gut is another area where more research is needed.


It Might Be Able To Boost Hair & Nail Growth

Schoenfeld says that, in addition to an improvement in joint pain, many people regularly consuming collagen also notice an increase in hair and nail growth. Dr. Barry Sears, Ph.D., the creator of the Zone Diet, also tells Romper by email that collagen is a good source of proline, which is the primary amino acid your body needs for hair and nail formation.

However, "ingestible collagen, such as in shakes, supplements, or powders, does not have any major proven benefit over ingesting any other form of protein," Rachel Nazarian, a New York-based dermatologist, told Health.com.


Collagen Might Improve Your Ability To Heal Wounds

Nutrition plays a huge role in wound healing. A 2018 study in Scientific Reports journal focused specifically on the participants' pressure ulcers and found that the wounds of the group who ingested the collagen hydrolysate healed more quickly. The researchers said their findings suggest that the collagen might affect the stem cells on the skin, resulting in improved healing.


There Are Concerns About Heavy Metals & Other Undesirable Things

If you're going to use a collagen supplement (or any other supplement), like with anything else, it's important to do your research. Dr. JoAnn Manson, chief of the division of preventative medicine at Boston’s Brigham and Women’s Hospital, told Time magazine that heavy metals including lead, cadmium, and other metals have “turned up again and again in supplements.” These metals can cause cancers, heart disease, and cognitive issues.

Schoenfeld agrees, noting that the quality and contents of the collagen you ingest is important. "There is some evidence that if animals are fed foods high in a certain pesticide, it could concentrate in the collagen protein," she explains.


It Might Increase Your Risk Of Kidney Stones

If you have a history of kidney stones, you might want to steer clear from collagen or enlist your doctor for guidance. "If you have a history or a family history of kidney stones, start with a small amount of collagen protein, as for some people it could increase their likelihood for kidney stones," Schoenfeld says. "You can gradually increase, but caution is advised."

That's because a diet high in animal proteins in general can be a factor in kidney stones, as noted by Harvard Medical School's site, Harvard Health. "Eating too much animal protein, such as red meat, poultry, eggs, and seafood, boosts the level of uric acid and could lead to kidney stones," Harvard Heath reported. "A high-protein diet also reduces levels of citrate, the chemical in urine that helps prevent stones from forming."

All in all, the research is still out on collagen in some respects, but some experts wholeheartedly endorse its use, as long as you do your research and make sure you're choosing a high-quality product. Knowing what you're getting into can help prevent any surprises and give you another option if you're dealing with something that collagen might be able to help.

Studies referenced:

Chen, Q., Chen, O., Martins, I., et al. (2017). Collagen Peptides Ameliorate Intestinal Epithelial Barrier Dysfunction in Immunostimulatory Caco-2 Cell Monolayers via Enhancing Tight Junctions, https://pubmed.ncbi.nlm.nih.gov/28174772/

Dar, Q., Schott, E., Catheline, S., et al. (2017). Daily oral consumption of hydrolyzed type 1 collagen is chondroprotective and anti-inflammatory in murine posttraumatic osteoarthritis, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5383229/

Sugihara, F., Inoue, N., and Venkateswarathirukumara, S. (2018). Ingestion of bioactive collagen hydrolysates enhanced pressure ulcer healing in a randomized double-blind placebo-controlled clinical study, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6065362/


Pamela Schoenfeld, MS, RD, LDN, registered dietitian and author of The Collagen Diet: Rejuvenate Skin, Strengthen Joints and Feel Younger by Boosting Collagen Intake and Production

Dr. Barry Sears, PhD, biochemist, author, and creator of the Zone Diet

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