Is there any evidence that hyluronic acid is effective orally.  I presently have my horses on legend.  FYI I’m a medical doctor. EC, Vermont

Dear EC,

The short answer is “yes.”  The paper entitled “Serum Hyaluronic Acid Levels in the Horse after Oral and Intravenous Administration” by Scott W. Pierce, DVM, that demonstrates this.  Here’s a summary of the study:

Ten horses were chosen for the study and divided into three groups.  Baseline blood samples were taken on each horse at the beginning of the study.  One group received 100mg HA daily in an oral gel preparation, the second group received a single intravenous dose of 40mg HA, and the third group was non-treated and served as controls.  Daily blood samples were drawn from each horse for seven days.

The oral HA group had the highest level of serum HA.  The oral group was the only group to have a substantial increase in serum HA by day seven. The intravenous group had a slight elevation by day four then by day seven, the HA level decreased to below baseline value.  The control group had a constant level.

Conclusion: The use of oral HA had a serum enhancing effect on circulating HA.  Therefore, daily supplementation with HA is necessary to increase the serum levels of HA. 

I should tell you that Dr. Pierce, the study coordinator, is not only a veterinarian on staff at Rood and Riddle Equine Hospital but also Director of Research and Development at Conquer, a company that sells an oral HA gel.  So to back up this study, here’s another study he co-authored, this time published in a peer-reviewed, scientific journal:

Oral hyaluronan gel reduces post operative tarsocrural effusion in the yearling thoroughbred.  In this study, 48 young horses underwent arthroscopic surgery to correct OCD lesions in the hock with half receiving an oral HA gel and half serving as controls.  The ones that were supplemented orally with HA had less swelling of the joint after surgery than those that didn’t.

Finally, I’ve included the following paper from a completely different set of scientists who set out to determine if HA is absorbed from the GI system and if so, where it goes in the body:

Absorption, distribution, excretion and tissue update of 99technetium-labeled hyaluronan (HA) after single oral doses in rats and beagle dogs. This paper presented at the 2008 FASEB meeting (Federation of Societies for Experimental Biology) provides direct evidence for the uptake of oral high molecular weight HA, with accumulation in connective tissue.