Using cannabis for pain relief helps, however, it makes pain more bearable rather than eliminating it, researchers at Oxford University's Center for Functional Magnetic Resonance Imaging of the Brain (FMRIB) reported in the journal Pain. Marijuana can have drastically different effects from one person to another. Some people report feeling happy or relaxed. Others report laughter, altered time and sensory perception, and increased appetite.
But marijuana can also cause less desirable effects.