November 2017 Issue

Ask the Expert: Collagen Peptides for Bones and Joints
By Toby Amidor, MS, RD, CDN
Today's Dietitian
Vol. 19, No. 11, P. 10

Q: Lately, I've been hearing that collagen peptides help alleviate bone and joint issues. What exactly are collagen peptides, and are their health claims evidence based?

A: Collagen is a protein that's part of bone, cartilage, and other tissues in humans and animals. People consume collagen from animals, such as chicken, bone broth (though bone broth has little collagen in it), or supplements. Collagen peptides are the broken down and more easily absorbed protein fragments of collagen, but most sources use the terms interchangeably. You'll find many Paleo advocates promoting collagen peptides, touting their ability to decrease joint pain associated with arthritis and surgery and improve overall bone and joint health. However, clinical studies on the role of collagen peptides in bone and joint health are limited.

A 2016 systematic review published in BMC Medicine looked at 197 studies starting in January 1980.1 Researchers found that based on the available literature, a significant amount of in vitro and in vivo evidence exists on many collagen peptides. They also found that several collagen peptides helped upregulate bone healing response in experimental models and potentially could be used for future clinical applications. However, based on the limited number of peptides studied in clinical trials, researchers have determined the results are limited and more research is needed.

Evidence also shows conflicting results, specifically regarding the effects of collagen on rheumatoid arthritis. A 1993 study published in Science found that taking collagen orally at 0.1 mg/day for one month followed by 0.5 mg/day for two months improved joint pain and swelling.2 However, a similar study published in 1999 in Arthritis & Rheumatology using the same dosage as the aforementioned study continued supplementation for five months, with results showing no improvements.3 A 2008 study published in Nutrition Journal found that collagen supplementation had short-term effects in relieving pain in subjects with osteoarthritis; however, the authors questioned whether the effects are long lasting.4

According to the Therapeutic Research Center Natural Medicines database, collagen type II—a major structural protein responsible for tensile strength and toughness in the cartilage—taken orally is possibly safe in doses up to 2.5 mg/day for no more than 24 weeks.5 Other collagen products, including bovine collagen, have caused allergic reactions. Possible side effects include nausea, heartburn, diarrhea, constipation, drowsiness, skin reactions, and headache. There are no known interactions with drugs, foods, herbs, and supplements at this time.

Recommendations for Practitioners
Some RDs recommend collagen supplements when counseling athletes. "Many in the Paleo community tout collagen for helping with skin, gut, and joint health in addition to improving performance," says Kim Feeney, MS, RD, CSSD, LD, CSCS, a sports performance dietitian for the US Air Force located in San Antonio. "There is research supporting some of these claims, but it is likely not the silver bullet it is described to be." Feeney believes the potential benefits of appropriately using a collagen supplementation protocol in conjunction with physical therapy outweigh any risks associated with taking the supplement. However, if a client chooses to take collagen supplements, they shouldn't be educated only about the potential side effects but also be made aware of the lack of clinical trials, especially since there isn't evidence of long-term efficacy.

— Toby Amidor, MS, RD, CDN, is the founder of Toby Amidor Nutrition ( and the author of the cookbook The Greek Yogurt Kitchen: More Than 130 Delicious, Healthy Recipes for Every Meal of the Day and The Healthy Meal Prep Cookbook. She's a nutrition expert for and a contributor to US News Eat + Run and

1. Pountos I, Panteli M, Lampropoulos A, Jones E, Calori GM, Giannoudis PV. The role of peptides in bone healing and regeneration: a systematic review. BMC Med. 2016;14:103.

2. Trentham DE, Dynesius-Trentham RA, Orav EJ, et al. Effects of oral administration of type II collagen on rheumatoid arthritis. Science. 1993;261(5129):1727-1730.

3. McKown KM, Carbone LD, Kaplan SB, et al. Lack of efficacy of oral bovine type II collagen added to existing therapy in rheumatoid arthritis. Arthritis Rheum. 1999;42(6):1204-1208.

4. Xie Q, Shi R, Xu G, Cheng L, Shao L, Rao J. Effects of AR7 Joint Complex on arthralgia for patients with osteoarthritis: results of a three-month study in Shanghai, China. Nutr J. 2008;7:31.

5. Natural medicines. Therapeutic Research Center website. Accessed September 17, 2017.