For arthritis sufferers, it may help protect the joint surface. It helps the body make proteoglycans, an important step in the making of cartilage cells. SAMe has the ability to reduce the pain and inflammation that are often part of osteoarthritis (OA). How this works remains unknown.

SAMe seems to work better than a placebo (sugar pill). It may work as well as a nonsteroidal antiinflammatory drug (NSAID), the most commonly used medication for OA. SAMe may not work as quickly as an NSAID. Pain relief is more likely to occur one to two weeks later.

But the pain relief may not last. Long-term effects may decline over time. This may be because SAMe is a mood elevator. It may actually work by decreasing a person's perception of pain. Your mother-in-law may have benefitted from the short-term effects of SAMe. But its effects on joint cartilage are less well known.