Varying Glucosamine Levels in Products

A Canadian study evaluating oral equine glucosamine supplements found glucosamine levels didn't always meet product label claims. Additionally, based on dosing recommendations and actual glucosamine content, the recommended maintenance dosage (10 grams of glucosamine per day) would not be achieved for the majority of products.

Scott Weese, DVM, DVSc, Dipl. ACVIM, a researcher in the department of Clinical Studies at Ontario Veterinary College, University of Guelph, said, "There were some supplements (in the study) that had levels of glucosamine that were less than what the labels said they contained. Some dosing instructions were less than the recommended daily dose. The standard recommendation of ten grams is still somewhat of a guess, but it is a reasonable recommendation and some products had levels that were very low and nowhere near that. Fortunately, most products did contain what they said they contained." Of the 23 supplements evaluated, nine contained less glucosamine than what was stated on the label.

Supplements that contained suboptimal levels of glucosamine concerned Weese. "You wonder if it will actually benefit the horse," he said.

Weese said it's a situation of "buyer beware." Because supplements aren't regulated by the USDA, as long as they don't make specific treatment claims (i.e. "this supplement treats osteoarthritis"), it can be hard to know which one will contain what the label claims. There are some "red flags" that Weese said consumers should be wary of:

  • The products are poorly labeled and have misspellings;
  • There is no guaranteed analysis of their content; or
  • The labels' claims are unreasonable.

"Still, at the end of the day you won't really know for sure if it's helping your horse," Weese said.

Will supplements be regulated by a government agency in the future? Weese said it seems inevitable.

Researchers in the study, which was was published in the January 2006 issue of the Equine Veterinary Journal, were Weese; Stacy Oke, DVM, MSc; Aghazadeh-Habashi, PhD; and Fakhreddin Jamali, PhD.

About the Author

Chad Mendell

Chad Mendell is the former Managing Editor for .

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