Joint FX, get it from my vet. Horse has been on it for about 3 years now and never stopped giving it once started.. I've queried with my vet whether it actually does any good. Earlier this year I ran out, horse was off it for about 3 weeks and became as stiff as a board within a few days. After about a week back on it, he was much improved again.
Horse is a 17yo 17hh IDxTB with ringbone and hock spavins. In his case, I noticed he became v stiff in his hocks once he wasn't getting it.
Suppleaze aviform gold, every horse i've ever fed it to has shown a significant difference in about 7-10 days. Honestly I rave about it so much you'd think i'm on commission (promise i'm not!), its just very effective and theres often a 3 for 2 offer on so reasonably priced too. I take the human version and my hands are so much better on it than off it.
Synequin whilst the insurance is paying for it...after that unsure as £180 for a box is a heck of a lot and I'd rather put that towards another lot of tildren
I use the aviform gold audits highly recommended on here, I don't know if it works but it's fairly economical do wouldn't stop using it now, I also feed micronised linseed which i think it good for joints as well as feet coat etc.
I started my new horse (15 yr old high mileage dressage horse with DJD in his stifles) on Easyjoint liquid (Equiform Nutrition) the day he arrived with me, and he feels very supple and comfortable on it. He managed to pop a 4"6 post and rail fence the other day, which was pretty impressive for a horse who was sold to me as a little bit stiff behind and needing an easier life!
Seraquin can also work well as a joint supplement for horses. At just over 65 pounds (that was the best price i found and was from viovet.co.uk), it is a lot cheaper than the synequin as well!
trialling a new one for Spillers - if the smell is anything to go by, it is wonderful!! Only been on it (horse BTW, not me) for a week so can't issue comment.