Dear Gemma, I concur with Paul. There are literally hundreds of studies, which support the use of natural nutrients like glucosamine to treat arthritis.
This meta-study for instance, quotes 30 studies to demonstrate that you can significantly improve pain, stiffness and physical function when you take NSAIDs such as Dolobid or Celecoxib together with glucosamine sulfate to treat your arthritis: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3346693/
Paul's suggestions above made me have a look around for you as to which nutrients and how much of them could be useful if helping you with your arthritis.
According to clinical studies published on the National Center for Biotechnology Information website the following nutrients have show beneficial effects in treating arthritis: Glucosamine Sulphate (minimum 1000 mg / day), Chondroitin Sulphate (minimum 500mg / day), MSM (minimum 300mg / day), DHA & EPA omega-3 fatty acids (minimum 200mg each / day), Hyaluronic acid (minimum 50mg / day), Collagen (minimum 300mg per day), zinc (10mg per day), selenium (minimum 50 mcg / day), manganese (minimum 1 mg / day), vitamin C (minimum 50 mg / day), vitamin D (minimum 20 mg / day), vitamin E (minimum 30 mg / day).
These dosages are all fairly low and should not be causing any side effects. However, please verify this list with your pharmacist.
Now, in practice you cannot possibly take all of these nutrients separately. You would be popping pills all day long. [lol]
I don’t want to recommend any specific arthritis supplement so please do your own research but buy the best you can afford. I would perhaps try to find one or two supplements, which include as many of these nutrients at the right dosages as possible.
BTW - I have not found any convincing studies for rose hip or green lipped mussel for example. It is up to you if you want to try those. The good news is that you have many alternatives. Do please investigate these yourself and discuss whatever you do with your GP and pharmacist.
I would love to hear from you how you have been getting on if you decide to go down this road. Good luck!