Muscle relaxers (also called muscle relaxants) are prescription medications that affect muscle function. Healthcare providers prescribe them to treat several symptoms, such as muscle spasms, spasticity and musculoskeletal pain. The term “muscle relaxant” refers to two major drug classes: antispastics and antispasmodics. These two classes differ in their uses, ways of working and side effects. This article focuses on skeletal muscle relaxants, as opposed to smooth muscle relaxants. Skeletal muscles are the muscles that help you move. Smooth muscles are the muscles that you don’t have control over, like the muscles in your intestine, stomach and blood vessels. There are also smooth muscle antispasmodic medications.

• Carisoprodol (Soma, Vanadom).

• Chlorzoxazone (Lorzone, Parafon Forte DSC, Relax-DS, Remular S).

• Cyclobenzaprine (Fexmid, Flexeril).

• Metaxalone (Metaxall, Skelaxin).

• Methocarbamol (Robaxin).

• Orphenadrine (Norflex).

The different types and brands of skeletal muscle relaxers work in different ways to affect muscle function. Most muscle relaxers act as central nervous system depressants and cause a sedative effect, or prevent your nerves from sending pain signals to your brain. In general, antispastic medications act on your spinal cord or skeletal muscle directly to improve muscle tightness (hypertonicity) and involuntary spasms. Antispasmodics decrease muscle spasms through changes in your central nervous system (brain and spinal cord).

There are no over-the-counter (OTC) muscle relaxants in the United States. But some OTC medications can help muscle issues (like soreness), such as NSAIDs (nonsteroidal anti-inflammatory drugs) and acetaminophen. Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. 

• Cerebral palsy.

• Multiple sclerosis (MS).

• Spinal cord injury.

• Stroke.

• Brain or head injury.