I have the same question! I was just recommending trying this by a new vet.
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I put my gelding on Equioxx about a month ago and will be starting the Zycosan this week. Iām kinda hoping the Zycosan will make it so I can take him off the Equioxx so Iām going to experiment. His comfort level is paramount so am completely willing to do both if necessary.
My poor guy is new to me so am figuring things out but definitely needs a lot of maintenance. (He turns 23 this month and has done a lot in his life.) We did Osphos in Feb, fetlock/pastern injections in March, and hock injections in April. His comfort level is SO much better as a result (go figure). Iām hoping the Zycosan will help so that I donāt have to repeat the injections as frequently.
FWIW, we did Adequan last fall but I didnāt see any difference.
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Anyone reporting back on availability?
I had no issues getting it.
I just started my horse on Arthropen (Pentosan 250mg/ml) @ 6ml per dose. Heās had his first two loading doses, two more to go. It cost me $500 for a 50ml vialā¦ ouch.
Wondering if people have had better success with giving it monthly (as is commonly done here), or giving the loading dose (4 x weekly) every six months.
Our dog is on it as he did his CCL at 4 years old in Jan, and the difference was amazing. He did the 4 x weekly course prior to surgery and by the final dose I was questioning if surgery was necessary!! The surgeon thinks he can be reduced off it now, post surgery.
Edit: Pretty sure that Arthropen is identical to Zycosan
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Youāre in Au correct? Iām a bit stumped as to why Pentosan was always 6ml and now the Zycosan dosage is 7.5ml. Havenāt seen comment or explanation on that.
But to answer your question- when I used I used it about 2x a month after loading it for my teenage gelding. That worked for him more than once a month. Some people just do the 4 dose treatment as needed too. I guess depends on what youāre treating and how the horse responds.
According to this, Zycosan is 250mg/mL of pentosan polysulfate sodium, plus 18.175mg of inactive ingredients. The labeled dose is 1.4mg/lb, which means a 1200lb horse should get 6.72mg, based on the trials for approval finding that various higher doses didnāt get more benefit. 6mL is much closer to what an 1100lb (average) horse should get but also, I have no idea what the inactive ingredients are in original Pentosan
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Are you still able to get this?
Yes
I am curious how either of these meds compare with Adequan. Why would you chose one over the other?
So far I feel like Iāve seen more results with Zycosan. And I like that I donāt have to give it as many times for the loading dose lol
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Most of the research on Adequan was done with intraarticular injections - directly into the joint. There is very little evidence that intramuscular injections of Adequan does anything at all. Of course, you will find people who swear by Adequan, but here is the science. Most research has shown no effect of intramuscular Adeuan. One paper that looked at IM injection in the MIA model suggested some positive effects, but there are some big caveats to that particular artificial model in horses.
https://pubmed.ncbi.nlm.nih.gov/?term=polysulfated+glycosaminoglycan+equine+intramuscular
There are a few papers that show chodroprotective effects of IM pentosan polysulfate in horses
https://pubmed.ncbi.nlm.nih.gov/?term=pentosan+polysulfate+equine+
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Wondering if you saw results with Zycosan? How long did they last?
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Iāve been following the Pentosan versus Adequan discussions and am going to try Zycosan (now FDA approved, renamed and yes, more expensive). I did see today (March 14, 2025) that Valley Vet has a $40 off rebate coupon for Zycosan on their website: Every little bit helps.
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Catching up with this discussion and saw your post. Did you take your gelding off of Equioxx? I have a 20-year old QH on Equioxx and have been using Adequan every 6-months. Iām ready to try Zycosan now and would also like to take my horse off Equioxx. I donāt think Cosequin ASU did a darn thing actually. I have had his stifles injected but my gosh thatās $500 twice a year now. Obviously, Iām driving an older car with a lot of miles on it - ha ha.
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I actually did maybe about 3 weeks ago . . . I had kept him on the Equioxx because he was feeling good and I was afraid to change anything. And then I mixed up my ordering deadline and ran out so decided it was a good time to take a break and see what happened.
So far, so good! We did another round of Osphos and joint injections in Oct/Nov, kept him on Equioxx until a few weeks ago. I actually have a box of Pentosan sitting in my dining room right now and Iām trying to decide when to give it to him. Balancing between wanting to give it to him before he starts showing any discomfort, but also trying to save pennies.
My trainer swears itās the Osphos. She says it usually take two injections and then they really improve (you do have to keep it up). I agree that the Osphos and the joint injections seem to be lasting longer this time than they did in early 2024, so there may be something to her theory.
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Thanks for your reply. It was very helpful. My QH competed in open reining. I bought him when he was 5 and about age 17 he started to show stifle issues, which is common for reining horses because of all that spinning early on. I feel fortunate that we have some approaches to help our horses with their issues.
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Thank you for this! Just applied for a rebate for a recent purchase from my vet.
