Learn about the side effects of methocarbamol, from common to rare, for consumers and healthcare professionals. Methocarbamol is a medication used to relieve muscle spasms, and relax neck and jaw muscle contraction (lockjaw) caused by tetanus, a serious bacterial infection. Methocarbamol is used to relieve the discomfort caused by acute (short-term), painful muscle or bone conditions. However, this medicine does not take the place of rest, exercise, physical therapy, or other treatment that your doctor may recommend for your medical problem. Methocarbamol is a muscle relaxant used to relieve pain and discomfort from muscle spasms. Learn about uses, dosage, side effects, and warnings. Overview: Methocarbamol is used short-term to relieve muscle, bone, and joint pain. It seems to relax muscles by affecting nerve activity in the spinal cord. Common side effects include dizziness. Methocarbamol 500 mg is a muscle relaxant used to relieve discomfort from acute musculoskeletal conditions like back strains, neck pain, and muscle spasms. It works by calming activity in the central nervous system rather than acting directly on the muscles themselves. Methocarbamol 500 mg treats acute muscle spasms and pain. Learn how it works, dosage, side effects, interactions, and how to save on the cost.