MS Contin^® is the brand name for morphine sulfate which is prescribed for moderate to severe pain. Morphine sulfate binds to the pain receptors in the brain so that the sensation of pain is reduced. MS Contin® comes in the form of tablets, capsules, liquid, and rectal suppository, which are taken every 4 hours. Long-acting tablets and capsules can be taken every 8-12 hours or 1-2 per day, respectively. Morphine sulfate is very addictive, so care must be taken to follow the doctor's instructions when taking MS Contin^®.