Glucosamine, derived largely from shrimp shells, is widely used by arthritis patients but it is less commonly found in combination with MSM, or methylsulfonylmethane, which is the isoxidised form of dimethyl-sulfoxide (DSMO).
It is however often taken along with chondroitin sulphate.
In the new study, both glucosamine and MSM improved osteoarthritis symptoms in subjects but when taken together the effect was greater than either alone.
"Combination therapy showed better efficacy in reducing pain and swelling and in improving the functional ability of joints than the individual agents," report the researchers in the June issue of Clinical Drug Investigations (vol 24, no6, pp 353-363).
More than 7 million adults in the UK - 15 per cent of the population - have long-term health problems due to arthritis and related conditions, according to the Arthritis Research Campaign, and 550,000 have moderate to severe osteoarthritis in their knees.
And across Europe the number of arthritis sufferers will continue to escalate as the population ages and other major risk factors, such as obesity, also increase.
Dr P Usha and M Naidu from Nizam's Institute of Medical Sciences in Hyderabad, India randomised 118 people with mild to moderate osteoarthritis to receive either 500mg glucosamine, 500mg MSM, a combination of both or placebo capsules three times daily for 12 weeks.
Patients were evaluated at prior to the study and several times during treatment for efficacy and safety.
After 12 weeks, the average pain score had fallen from 1.74 to 0.65 in those taking only glucosamine. In MSM-only participants, it fell from 1.53 to 0.74. However, in the combination group, it fell from 1.7 to 0.36.The researchers also found that the combination treatment had a faster effect on pain and inflammation compared to glucosamine alone.
"It can be concluded that the combination of MSM with glucosamine provides better and more rapid improvement in patients with osteoarthritis," write the researchers.