Having found this article on the effectiveness of the New Zealand Green Lipped Mussel in aiding joint pain, I had to look a little deeper. The article can be found here. It all sounds very promising until I actually speak to my vet who says that its never actually been tested in a clinical trial as far as he is aware on anything apart from humans (on which the green lipped mussel supplement also works very well).
After additional research to try and find a decent study on the effeciveness of this supplement in horses, I came across this clinical trial here. Which essentially states that when tested on horses, the product really does work. Other products that are also thought to be effective are Omega 3 oils, avocado and soyabean unsaponifiable, oral hyalauronic acid, hyaluronic acid and cetyl myristoleate. Some of these products people will know well, and others are not so common but still proven effective.
I am now in search of a product that contains as many of these ingredients as possible and have so far found a product called Maxavita that does offer some of the ingredients and also direct from New Zealand here. Maxavita is available here in the UK but the GlycOmega Plus only seems to come from New Zealand. I am currently trying to order some and then intend to test on my horse and see if we can get some good results. I shall let you know how I get on.