We mostly just feed MSM, though I have been supplementing my horse with additional oral supplements this past year as a preventative (hopefully… though maybe it just makes me feel better). I really like Max Flex HR just based on price, palatability, and product information. Though it is hard to tell how much it is ‘working’ since I’m using it on an 8yo horse who has never shown any issues. I take Osteo Bi-Flex Double Strength and I do think it helps me, so my hope is that feeding something with similar ingredients helps my horse.
At a recent clinic, we had a presentation from a company called Joint Charge that is local to the area and has recently expanded to the equine market with their supplement. It is oral liquid, but apparently is better because you receive it dry and mix it with water yourself (good for 90 days after) and therefore the molecules are not breaking down as quickly as the liquid you buy off the shelf. Any of the COTHer scientists want to weigh in on this? I know a few people who have used it so far and say they see a difference with their horses. It is just much pricier than what I’m currently feeding.