I think that Equine America Cortaflex is fantastic: I used it on my old share horse when he developed arthiritis, and an ex-racer with a twingey back, and it was very effective. Initially it was pretty expensive but it turned out to be excellent value for money and lasted a long time.
I cannot recommend Equine Answers range of joint supplements enough, I own a tack shop in Norway and sell the Cortaflex range and Equine Answers. Equine Answers Premier Flex is our best selling supplement.
I have used both on an arthritic horse and another with filling in hinds overnight when stabled. I used to use Cortaflex then came across Equine Answers and have never looked back. Cheaper than Cortaflex and more effective with great product support via helpline.
I have no reason to endorse the product as I live in Norway and my business in Norway. I just like to share what I know works ;-)
Another vote for Premierflex. I use the premierflex plus on my veteran pony and she looks and feels fantastic! Even the farrier commented that her feet and legs are the best they have ever been. She has only been on it for 3 months and he has been shoeing her for 5 years!
4 months supply cost £45 and you use so little of it! Amazing stuff and fab customer service too!
My friend has a horse who has been turned away for 6 months following injury. Vet said she would never be sound again.......6 months later she is sound and being brought back into work carefully. Vet can not believe it!
I use Equimins products, at the moment. They've a range of joint support products Joint supplements. I've a rising 3 year old filly with pronounced bench knees and have been using the Equimins Flexijoint Cartilage Supplement as a prophylactic for 2 years now. It's extremely palatable (smells lovely), is reasonably priced for long term use and I am hoping it will help her in the long term.