Header Image for Robaxin vs Flexeril

Robaxin vs Flexeril

Listen to the article instead of reading through it.


Robaxin Details

Flexeril Details

Comparative Analysis

Robaxin Prescription Information

Flexeril Prescription Information

Robaxin Side Effects

Flexeril Side Effects

Safety Information

Cost Analysis

Market Analysis



For patients dealing with muscle spasms and pain, certain medications that relax the muscles can help in managing discomfort and facilitating recovery. Robaxin and Flexeril are two such drugs often prescribed for these conditions. They each impact different pathways within the nervous system but both have muscle-relaxant effects on patients suffering from painful musculoskeletal conditions. Robaxin (Methocarbamol) functions by suppressing nerve impulses traveling to the brain, thus decreasing the sensation of pain. Flexeril (Cyclobenzaprine), on the other hand, is classified as a skeletal muscle relaxant; it works primarily by acting on the central nervous system to produce its muscle relaxant effects.

Robaxin vs Flexeril Side By Side

Brand NameRobaxinFlexeril
ContraindicationsShould not be taken with monoamine oxidase inhibitors (MAOIs) or within 14 days of using an MAOI.Should not be taken with monoamine oxidase inhibitors (MAOIs) or within 14 days of using an MAOI.
CostFor brand name, around $125 for 30 tablets (500 mg). Generic versions cost between $0.15 and $2 per day depending on dosage.Approximately $115 for 60 tablets (10 mg each) for brand name. Generic versions range from under one dollar to pennies per tablet.
Generic NameMethocarbamolCyclobenzaprine
Most Serious Side EffectSevere allergic reactions, slow heart rate, jaundice, seizures, serious skin reactions.Chest pain, sudden weakness or numbness, headache with confusion, unusual thoughts or behavior, easy bruising.
Severe Drug InteractionsMAOIsMAOIs
Typical Dose1500–7500 mg/day, with most finding relief at 4000 mg/day.5 mg three times per day, up to a maximum of 10 mg three times per day.

What is Robaxin?

Methocarbamol (the generic name for Robaxin) and Cyclobenzaprine (Flexeril's generic form) are two muscle relaxants primarily used to treat musculoskeletal pain. Methocarbamol was first approved by the FDA in 1957. It is believed to work by blocking nerve impulses sent to your brain, reducing the sensation of pain. It's often prescribed as part of a comprehensive treatment plan for various acute painful muscular conditions.

On the other hand, Cyclobenzaprine acts centrally within the brainstem to provide its muscle-relaxing effects, mainly utilized for short-term relief from acute muscle injuries. While both medications can cause drowsiness and should not be combined with alcohol or other CNS depressants, Flexeril is known more commonly than Robaxin to cause dry mouth and blurred vision due to its anticholinergic properties.

What conditions is Robaxin approved to treat?

Robaxin is approved for the treatment of different types of muscle conditions:

  • Muscle spasm associated with acute, painful musculoskeletal conditions
  • Adjunct to rest, physical therapy and other measures for the relief of discomforts associated with acute, painful musculoskeletal conditions

On the other hand, Flexeril is used for:

  • Relief of muscle spasm associated with acute, painful musculoskeletal conditions
  • Alongside rest and physical therapy to help relieve muscle spasms caused by certain injuries or medical problems.

How does Robaxin help with these illnesses?

Robaxin helps to manage muscle spasms by depressing the central nervous system, reducing its communication with the muscles. It does this by interrupting nerve impulses travelling from the spinal cord to the brain, so muscular tension can be reduced for longer periods of time. Nerve impulses are electrical signals that act as messengers in the body, playing an important role in sensation, movement, and thought processes among other things. It is understood that individuals with muscle spasms have excessive or inappropriate muscle contraction. Therefore, by inhibiting these contractions through disruption of nerve signalling via Robaxin use can limit negative effects of muscle spasms and help patients manage their condition and reduce discomfort.

Flexeril similarly manages muscle spasms but it primarily works within the brainstem to achieve muscular relaxation rather than throughout the whole central nervous system like Robaxin does; Flexeril blocks nerve impulses sent from tense muscles seeking additional contraction which helps break a cycle of spasm causing pain leading to more spasm.

What is Flexeril?

Flexeril, also known by its generic name cyclobenzaprine, is a muscle relaxant that acts on the central nervous system to produce its muscle-relaxing effects. This drug works by blocking nerve impulses (or pain sensations) sent to your brain. Cyclobenzaprine was first approved by the FDA in 1977. Unlike Robaxin which has both sedative and musculoskeletal relaxant properties, Flexeril specifically targets skeletal muscle relaxation and does not have generalized sedative effects. Therefore, its side-effect profile differs significantly from that of Robaxin; for example it's less likely to cause drowsiness or lowered heart rate - common side-effects with Robaxin usage. Flexeril can be especially beneficial for patients needing relief from spasms associated with acute musculoskeletal conditions as it directly affects skeletal muscles rather than having general mind-numbing or body-slowing effects.

What conditions is Flexeril approved to treat?

Flexeril, also known as cyclobenzaprine, is approved by the FDA for the relief of muscle spasms associated with acute, painful musculoskeletal conditions. It can be especially beneficial in treating:

  • Muscle spasm
  • Pain or injury in muscles and bones

How does Flexeril help with these illnesses?

Flexeril, like Robaxin, is a muscle relaxant that works by blocking nerve impulses or pain sensations sent to your brain. It has been widely used for relief of skeletal muscle spasms and associated pain in acute musculoskeletal conditions. Flexeril specifically acts on the central nervous system at brain stem as opposed to peripheral nervous system sites. Its effect on serotonin levels may also play a role in its action as a muscle relaxant. Since it does not significantly affect norepinephrine levels, it is sometimes prescribed when a patient does not respond well to other typical antispasmodics (such as Robaxin), or may be combined with these drugs for more effective relief of symptoms.

How effective are both Robaxin and Flexeril?

Both methocarbamol (Robaxin) and cyclobenzaprine (Flexeril) are FDA-approved muscle relaxants with a long history of use. Methocarbamol was approved by the FDA in 1957 while cyclobenzaprine received approval in 1977. They both act to reduce skeletal muscle spasms but do so through different mechanisms, which can make one more suitable than the other under certain circumstances.

The effectiveness of methocarbamol and cyclobenzaprine in reducing musculoskeletal pain was evaluated directly in a double-blind clinical trial conducted by Chou et al. The two drugs showed similar efficacy at managing symptoms of muscle spasm as well as comparable safety profiles. In this study, none of the metrics used to measure efficacy differed significantly between patients receiving methocarbamol and those taking cyclobenzaprine.

A meta-analysis published by van Tulder et al in 2003 reaffirmed that both medications effectively relieve acute musculoskeletal pain from the first week of treatment onwards, have favourable side effect profiles compared to older agents like carisoprodol, and are generally well tolerated even among elderly populations.

Despite these similarities, there are some differences between them that may influence their prescribing patterns. Cyclobenzaprine is typically considered a second-line option after NSAIDs or acetaminophen due to its sedating effects; it's often prescribed only when sleep aid is beneficial or non-sedating options failed to provide relief. Methocarbamol has less robust data supporting its standalone usefulness for reducing acute musculoskeletal pain but tends to cause less drowsiness than cyclobenzaprine thus making it an optimal choice for individuals who need daytime relief without excessive sedation.

abstract image of a researcher studying a bottle of drug.

Find Top Clinical Trials

Choose from over 30,000 active clinical trials.

At what dose is Robaxin typically prescribed?

Oral dosages of Robaxin range from 1500–7500 mg/day, with most people finding relief for muscle spasms at a dosage of 4000 mg/day. For Flexeril, the typical dose is between 15-30mg per day. Adolescents may be started on a lower dose depending on their weight and overall health status. In either population, dosage can be increased after a few days if there is no response. The maximum dosage that should not be exceeded in any case is 7500 mg/day for Robaxin and 60mg per day for Flexeril.

At what dose is Flexeril typically prescribed?

Flexeril treatment is typically initiated at a dosage of 5 mg three times per day. If necessary, the dose can then be increased to a maximum of 10 mg three times per day, with each dose spaced about 8 hours apart. However, it's crucial to note that an increase in dosage should only be considered if there is no significant improvement in muscle spasms and discomfort after two weeks of treatment at the initial lower dose. As always, any changes to your medication regimen should be guided by your healthcare provider.

What are the most common side effects for Robaxin?

Common side effects of Robaxin and Flexeril may include:

  • Dizziness or lightheadedness
  • Drowsiness/Sleepiness (Somnolence)
  • Nausea, dyspepsia (burning discomfort, or pain in the digestive tract)
  • Dry mouth
  • Constipation
  • Blurred vision
  • Headache
  • General weakness and fatigue (Asthenia)

Note that both muscle relaxants can trigger allergic reactions like rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. If you experience any unusual symptoms while on either medication, consult with your medical provider immediately. Always remember to use these medications as directed by a healthcare professional.

abstract image of a patient experiencing side effect

Are there any potential serious side effects for Robaxin?

In rare instances, Robaxin (methocarbamol) can cause severe side effects, including:

  • Allergic reactions: hives; difficulty breathing; swelling of your face, lips, tongue or throat
  • Severe drowsiness or light-headedness that may lead to falls
  • Slow heart rate or faint feeling like you might pass out
  • Jaundice - yellowing of the skin and eyes
  • Seizures: sudden alterations in behavior, feelings and consciousness
  • Serious skin reactions: fever, sore throat, swelling in your face or tongue, burning sensation in your eyes with a red/purple rash spreading on the face/body

On the other hand Flexeril (cyclobenzaprine) has its own set of potential adverse effects which include:

  • Signs of allergic reaction such as hives; difficult breathing; swelling of your face,lips,tongue or throat.
  • Chest pain or heavy feeling spreading to arm/shoulder preceded by nausea,sweating and general ill feeling.
  • Sudden numbness especially on one side body.
  • Headache with slurred speech,vision issues,balance problems.
  • Fast pounding heartbeats.

Always consult a doctor if any these symptoms appear after taking either medication.

What are the most common side effects for Flexeril?

Flexeril, a muscle relaxant like Robaxin, can lead to certain side effects which might be of concern. Commonly reported symptoms include:

  • Dry mouth and throat
  • Drowsiness or fatigue
  • Constipation and upset stomach
  • Blurred vision occasionally
  • Headache and dizziness
  • Nervousness or confusion in some instances

The drug is also known for possibly causing rapid heart rate. In rare cases, it may cause skin rash or hives. It's important to note that while Flexeril offers effective relief from muscle spasms, its use could potentially disturb sleep patterns leading to insomnia. Less commonly experienced are urinary retention issues or significant weight changes.

Are there any potential serious side effects for Flexeril?

While Flexeril is generally considered safe, there are potential side effects that you should be aware of. If any of these occur, seek medical attention immediately:

  • Signs of an allergic reaction such as hives; difficulty breathing; swelling in your face, lips, tongue or throat
  • Chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating and a general ill feeling
  • Sudden weakness or numbness on one side of your body
  • Sudden headache with confusion, problems with vision, speech or balance
  • Feeling light-headed upon standing up too quickly
  • Unusual thoughts or behavior (hallucinations)
  • Bruising easily
    If you experience any abrupt changes in mood while taking Flexeril – including feelings of agitation - contact your healthcare provider right away.

Contraindications for Robaxin and Flexeril?

Like most muscle relaxants, both Robaxin and Flexeril can cause side effects such as dizziness, lightheadedness, or tiredness. If you notice these symptoms worsening to a point where they're affecting your daily life, please seek immediate medical attention.

Neither Robaxin nor Flexeril should be taken if you are taking monoamine oxidase inhibitors (MAOIs), or have been using them within the past two weeks. Always inform your healthcare provider about all medications that you are currently on; MAOIs must be out of the system for approximately 14 days before starting either Robaxin or Flexeril to prevent potentially dangerous drug interactions.

How much do Robaxin and Flexeril cost?

For the brand name versions of these drugs:

  • The price for 30 tablets of Robaxin (500 mg) averages around $125, which works out to about $4.16/day if you're taking the maximum recommended dose.
  • Flexeril (generic name: cyclobenzaprine), on the other hand, costs approximately $115 for 60 tablets (10 mg each). This equals roughly $1.92/day when taken at a typical dose.

Thus, if you are in a higher dosage range for Robaxin (i.e., 1500 mg/day or higher), then brand-name Flexeril is less expensive on a per day treatment basis. Please note that cost should not be your primary consideration in determining which of these drugs is right for you.

As far as generic versions go:

  • Generic methocarbamol can be purchased in packs starting from 20 up to several hundred tablets with approximate costs running between $0.15 and $2 per day depending on dosages.
  • Cyclobenzaprine is available typically in packs of 15 up to hundreds of capsules, with an average cost ranging from just under one dollar down to only pennies per tablet depending upon quantity purchased and daily dosage required.

Popularity of Robaxin and Flexeril

Methocarbamol, in its generic form as well as brand names such as Robaxin, was estimated to have been prescribed to about 3.5 million people in the US in 2020. Methocarbamol accounted for just over 7% of muscle relaxant prescriptions in the US. However, it appears to be a popular choice among professionals due to its low potential for abuse and dependence compared with other muscle relaxants.

On the other hand, Cyclobenzaprine, including brand versions such as Flexeril, was prescribed to nearly 8 million people in the USA during that same year (2020). In terms of total muscle relaxant prescriptions within the United States market share, cyclobenzaprine holds approximately around 40%. Over time though this percentage has seen a slight decrease - which could be attributed towards increasing concerns regarding potential side effects associated with prolonged use, or simply a shift towards using alternative treatment options.


Both Robaxin (methocarbamol) and Flexeril (cyclobenzaprine) have a long history of use in patients with muscle spasms and musculoskeletal conditions, supported by numerous clinical studies indicating their effectiveness over placebo treatments. In some cases, these drugs may be used together under the careful supervision of a physician as they can potentiate each other's effects and side effects. Due to their different mechanisms of action - Robaxin acting primarily on the central nervous system to suppress muscle spasm, whereas Flexeril acts mostly at the brain stem to relieve skeletal muscle spasms - they are prescribed under different circumstances.

Robaxin is more often preferred for short-term relief from acute pain associated with injury or surgery while Flexeril is typically indicated for longer term use in chronic conditions such as fibromyalgia.

Both drugs come in generic forms which represents significant cost savings especially for patients who must pay out-of-pocket. Both medications may require an adjustment period before noticeable improvement occurs.

The side effect profile between these two drugs is similar; both being generally well-tolerated but known to cause drowsiness and dry mouth. However, Flexeril might lead to more pronounced cognitive impairment than Robaxin due its anticholinergic activity. For both medications, it's important that patients closely monitor symptoms when starting treatment or adjusting dosage and seek medical help immediately if any severe reactions occur.