What Is Myelax? Understanding the Muscle Relaxant Eperisone

October 6, 2025 •

4 min read

Myelax is a brand name medication containing the active ingredient eperisone hydrochloride, a centrally-acting muscle relaxant used to treat muscle spasms and spasticity in several countries. Unlike many other muscle relaxants, studies suggest eperisone may have a lower incidence of sedation, making it a valuable option for patients requiring therapy without significant reduction in alertness.

Quick Summary

Myelax, a brand of eperisone, is a centrally-acting muscle relaxant that treats muscle spasms and stiffness. It also has a vasodilatory effect and is used for conditions like low back and neck pain. Its mechanism involves relaxing skeletal and vascular muscles with a lower sedative effect than some other similar drugs.

Key Points

Myelax is Eperisone: Myelax is a brand name for the generic drug eperisone hydrochloride, a centrally-acting muscle relaxant and antispasmodic.
Less Sedation: Unlike some other muscle relaxants, eperisone is noted for having a lower incidence of sedation, which helps patients maintain alertness.
How It Works: It relaxes both skeletal and vascular smooth muscles by acting on the central nervous system, and also has a vasodilatory effect that improves blood circulation.
Treats Various Conditions: Myelax is used for treating muscle spasms and stiffness associated with cervical spondylosis, low back pain, shoulder periarthritis, and spastic paralysis.
Common Side Effects: Reported side effects include dizziness, weakness, drowsiness, nausea, and headache.
Geographical Availability: Myelax and its active ingredient, eperisone, are not FDA-approved in the United States but are available in other countries.

What Exactly Is Myelax?

Myelax is a pharmaceutical product with the active ingredient eperisone hydrochloride. It is classified as a centrally-acting muscle relaxant and an antispasmodic agent. It is important to note that while widely used in countries like the Philippines and parts of Asia, eperisone is not approved for use by the Food and Drug Administration (FDA) in the United States.

Unlike many conventional muscle relaxants that primarily cause sedation, eperisone is known for its ability to relax muscles with a lower risk of drowsiness. This allows it to be used in therapeutic contexts where maintaining alertness is important, such as during rehabilitation.

How Does Eperisone, the Active Ingredient in Myelax, Work?

The therapeutic action of Myelax is attributed to its active ingredient, eperisone hydrochloride. Its mechanism of action is multi-faceted, affecting both the central nervous system and vascular smooth muscle.

Eperisone works in the following ways:

Relaxes Skeletal Muscles: It acts on the spinal cord to suppress spinal reflex potentials and reduce the sensitivity of muscle spindles via gamma motor neurons. This action decreases hypertonia, or abnormally increased muscle tone, which is the root cause of muscle stiffness and spasm.
Acts as a Vasodilator: Eperisone dilates blood vessels, leading to improved blood circulation within the muscles. This enhanced blood flow can aid in reducing pain and promoting healing in affected areas.
Provides Analgesic Action: By suppressing the pain reflex in the spinal cord, eperisone helps to alleviate pain associated with muscle stiffness and spasms.

Common Uses and Indications for Myelax

Myelax is prescribed for the symptomatic treatment of muscle spasm and spasticity resulting from various conditions. Its primary uses focus on alleviating pain and stiffness in the neck, shoulders, and back.

Conditions treated with Myelax include:

Cervical Spondylosis: Pain and muscle tension in the neck caused by degeneration of the neck vertebrae.
Lumbar Back Pain: Acute or chronic low back pain with associated muscle spasms.
Shoulder Periarthritis: Conditions involving inflammation and pain around the shoulder joint, also known as "frozen shoulder".
Spastic Paralysis: Muscle stiffness and spasms resulting from central nervous system disorders such as cerebrovascular disease, cerebral palsy, and multiple sclerosis.
Trauma-Related Spasticity: Sequelae following injury to the brain or spinal cord.

Dosage and Administration

Myelax is typically administered orally. The appropriate dosage and frequency of administration are determined by a healthcare provider based on the individual's condition and symptoms. Adherence to the prescribed regimen is crucial for both efficacy and safety.

Side Effects and Safety Considerations

While generally well-tolerated, Myelax can cause side effects. Patients should be aware of these and inform their doctor if they experience any adverse reactions.

Common side effects include:

Dizziness and drowsiness
Nausea and stomach discomfort
Headache
Weakness or fatigue
Skin rashes

Severe but rare side effects include shock or anaphylactoid reactions. Patients experiencing symptoms like itching, redness, swelling, or difficulty breathing should seek immediate medical attention.

Myelax is contraindicated in patients with a known hypersensitivity to the drug or those with severe myasthenia. Caution is also advised for patients with liver function disorders, and liver function should be monitored during treatment. Due to potential risks, Myelax is not recommended for use during pregnancy or breastfeeding.

Comparison with Other Muscle Relaxants

Myelax (eperisone) differs from many other centrally-acting muscle relaxants. The comparison below highlights some of these distinctions based on available research and common knowledge of these drugs.


Feature	Myelax (Eperisone)	Cyclobenzaprine (Flexeril)	Metaxalone (Skelaxin)
Mechanism	Acts centrally to relax skeletal and vascular smooth muscles. Exhibits a vasodilatory effect.	Acts on the CNS to reduce muscle spasms, but its precise mechanism is not fully understood.	Acts on the CNS to produce general CNS depression, leading to muscle relaxation.
Sedation Profile	Relatively low incidence of sedation, making it suitable for patients needing to maintain alertness.	Significant sedation is a common side effect due to its anticholinergic properties.	Fewer reports of sedation and other side effects compared to other muscle relaxants.
Common Side Effects	Dizziness, drowsiness, nausea, headache, weakness.	Drowsiness, fatigue, dry mouth, dizziness.	Drowsiness, dizziness, nausea, stomach upset.
Geographical Availability	Not approved in the US; available in countries like the Philippines and India.	Widely available and prescribed in the US and other countries.	Available in the US; considered a safer alternative by some clinicians.

Conclusion

Myelax, with its active ingredient eperisone, is a medication primarily used in several countries as a centrally-acting muscle relaxant and antispasmodic. Its therapeutic benefits extend to conditions causing muscle stiffness and pain, including low back pain, cervical spondylosis, and spastic paralysis. Its distinguishing feature is its lower sedative effect compared to many other muscle relaxants, which can be advantageous for patients undergoing rehabilitation. While it is important for potential users to be aware of possible side effects like dizziness and nausea, Myelax offers an effective treatment option for muscle-related ailments in regions where it is medically available. Anyone considering this medication should consult a healthcare provider to ensure it is the right treatment for their specific condition.

For more detailed information on the active ingredient, refer to the DrugBank entry on Eperisone.

Frequently Asked Questions

Myelax is used for the symptomatic treatment of muscle spasm and spasticity. This includes conditions such as cervical spondylosis (neck pain), lower back pain, shoulder periarthritis, and spastic paralysis stemming from central nervous system disorders like cerebral palsy or stroke.

No, Myelax (eperisone) is not approved for use in the United States by the Food and Drug Administration (FDA). It is available in other countries, including the Philippines, India, and South Korea.

A key difference is Myelax's active ingredient, eperisone, which is associated with a lower incidence of sedation compared to other muscle relaxants like cyclobenzaprine. This can be beneficial for patients who need to remain more alert during treatment.

Common side effects include weakness, dizziness, drowsiness, headache, nausea, and gastrointestinal discomfort. If these symptoms occur, it is often recommended to reduce the dosage or discontinue the medication under medical supervision.

Caution is advised regarding interactions. For example, ocular accommodation disturbances have been reported with the concomitant use of eperisone and methocarbamol. It is crucial to inform your doctor about all other medications you are taking to avoid potential drug interactions.

Myelax is contraindicated for individuals with a history of hypersensitivity to the drug's ingredients or those with severe myasthenia. It is also not recommended for use by pregnant or breastfeeding women.

The administration of Myelax, including the specific amount and timing, should always follow the instructions provided by your prescribing physician.