Soma 500mg has an active compound that is carisoprodol which is a muscle relaxant that works by blocking pain signals from the nerves to the brain. Rest and physical therapy both are used to treat skeletal muscle conditions such as pain or injury. Because there is little research on Soma’s effectiveness in long-term use, and most skeletal muscle injuries are short-term, therefore soma 500mg should only be used for a few weeks (up to two or three weeks).