Methocarbamol: uses, dosing, side effects & brands
Methocarbamol is a muscle relaxant sold in the U.S. under 3 brand and generic names, for muscle cramp, muscle rigidity and myositis. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Muscle Relaxant
- Treats (across its forms)
- Muscle Cramp, Muscle Rigidity and Myositis
- Available as
- Injectable · Suspension · Tablet
- Sold as
- 3 products — Robaxin, Atmeksi and Methocarbamol
- Prescription?
- Prescription only
- Generic available?
- Yes
- Half-life
- about 1 to 2 hours
- What the pharmacy pays
- about $1 for a 30-count supply — not your price
How Robaxin is dosed
From the FDA label for Robaxin (application NDA011790). Other methocarbamol products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
For Intravenous and Intramuscular Use Only. Total adult dosage should not exceed 30 mL (3 vials) a day for more than 3 consecutive days except in the treatment of tetanus. If the condition persists, a like course may be repeated after a drug-free interval of 48 hours. Dosage and frequency of injection should be based on the severity of the condition being treated and therapeutic response noted. For the relief of symptoms of moderate degree, one dose of 1 gram (one 10 mL vial) may be adequate. Ordinarily this injection need not be repeated, as the administration of the oral form will usually sustain the relief initiated by the injection. For the severest cases or in postoperative conditions in which oral administration is not feasible, additional doses of 1 gram may be repeated every 8 hours up to a maximum of 3 g/day for no more than 3 consecutive days. Directions for Intravenous Use ROBAXIN Injectable may be administered undiluted directly into the vein at a maximum rate of three mL per minute. It may also be added to an intravenous drip of Sodium Chloride Injection (Sterile Isotonic Sodium Chloride Solution for Parenteral Use) or five percent Dextrose Injection (Sterile 5 percent Dextrose Solution); one vial given as a single dose should not be diluted to more than 250 mL for I.V. infusion. AFTER MIXING WITH I.V. INFUSION FLUIDS, DO NOT REFRIGERATE. Care should be exercised…
Everything below is the FDA label for Robaxin (injectable). Methocarbamol is also sold as suspension and tablet, and those are different medicines to take — follow the label for the one you were prescribed.
Robaxin side effects
The following adverse reactions have been reported coincident with the administration of methocarbamol. Some events may have been due to an overly rapid rate of intravenous injection. Body as a whole: Anaphylactic reaction, angioneurotic edema, fever, headache Cardiovascular system: Bradycardia, flushing, hypotension, syncope, thrombophlebitis In most cases of syncope there was spontaneous recovery. In others, epinephrine, injectable steroids, and/or injectable antihistamines were employed to hasten recovery. Digestive system: Dyspepsia, jaundice (including cholestatic jaundice), nausea and vomiting Hemic and lymphatic system: Leukopenia Immune system: Hypersensitivity reactions Nervous system: Amnesia, confusion, diplopia, dizziness or light-headedness, drowsiness, insomnia, mild muscular incoordination, nystagmus, sedation, seizures (including grand mal), vertigo The onset of convulsive seizures during intravenous administration of methocarbamol has been reported in patients with seizure disorders. The psychic trauma of the procedure may have been a contributing factor. Although several observers have reported success in terminating epileptiform seizures with ROBAXIN Injectable, its administration to patients with epilepsy is not recommended (see PRECAUTIONS, General ). Skin and special senses: Blurred vision, conjunctivitis, nasal congestion, metallic taste, pruritus, rash,…
Who shouldn’t take Robaxin
ROBAXIN Injectable should not be administered to patients with known or suspected renal pathology. This caution is necessary because of the presence of polyethylene glycol 300 in the vehicle. A much larger amount of polyethylene glycol 300 than is present in recommended doses of ROBAXIN Injectable is known to have increased pre-existing acidosis and urea retention in patients with renal impairment. Although the amount present in this preparation is well within the limits of safety, caution dictates this contraindication. ROBAXIN Injectable is contraindicated in patients hypersensitive to methocarbamol or to any of the injection components.
Robaxin drug interactions
See WARNINGS and PRECAUTIONS for interaction with CNS drugs and alcohol. Methocarbamol may inhibit the effect of pyridostigmine bromide. Therefore, methocarbamol should be used with caution in patients with myasthenia gravis receiving anticholinesterase agents.
Can you take methocarbamol with…?
Source-cited answers for the combinations people actually ask about — each with a verdict and what to watch for.
Every methocarbamol product we track (3)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
| # | Drug | Rating | Type | Form | Generic? | Pharmacy pays | |
|---|---|---|---|---|---|---|---|
| 1 | 72/100 | Prescription | Injectable | Generic | $1 | View → | |
| 2 | Not yet rated | Prescription | Suspension | Generic | $1 | View → | |
| 3 | Not yet rated | Prescription | Injectable | Generic | $1 | View → |
What methocarbamol pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
Combination products containing methocarbamol
A combination is a different drug — different dosing, different warnings. It is listed here so you can find it, not so you can substitute it.
Methocarbamol recalls
From the FDA Enforcement database. A recall covers specific lots — not the drug as a whole.
How long methocarbamol keeps
No methocarbamol label we read sets a separate limit for after opening, but they do specify how it must be stored — and the stability behind any date assumes those conditions.
Does methocarbamol expire? The in-use limits and storage rules from its labelsWhat people report to the FDA about methocarbamol
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 17,377 reports naming methocarbamol, and the FDA flagged 63% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- fatigue1,289 reports
- nausea1,244 reports
- headache986 reports
- diarrhoea889 reports
- fall820 reports
- dyspnoea819 reports
- arthralgia790 reports
- dizziness734 reports
Read these as a signal, not a rate. A report does not mean methocarbamol caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved August 25, 2026.
How long methocarbamol stays in your system
The elimination half-life of methocarbamol is about 1 to 2 hours. The FDA label reports a mean plasma elimination half-life of 1 to 2 hours in healthy volunteers (about 1.1 hours in a younger group). It names no active metabolite: methocarbamol is cleared by dealkylation, hydroxylation and likely conjugation, and essentially all metabolites leave in the urine, with the label describing no lingering active one. Older adults clear it only slightly more slowly (mean 1.5 hours at a mean age of 69, vs 1.1 hours in a younger group). Kidney impairment barely changes the half-life — in 8 hemodialysis patients it was 1.2 hours vs 1.1 hours in normal subjects — even though total clearance fell about 40%. Liver disease matters most: in 8 patients with alcohol-related cirrhosis, total clearance dropped roughly 70% and the mean half-life rose to about 3.4 hours. Protein binding is 46-50% normally and drops to roughly 40-45% in cirrhosis and 41-43% in older adults. These figures come from immediate-release oral tablets and the IM/IV injection; the label covers no extended-release methocarbamol form.
Methocarbamol Tablets USP — FDA label, Clinical Pharmacology (Pharmacokinetics), DailyMed ↗Half-life is how long the body takes to clear half a dose. It is not the same as how long a drug test can detect it, and it varies with age, kidney and liver function.
Related calculators
Frequently asked questions
What is Robaxin?
Robaxin (Methocarbamol) is a muscle relaxant used to treat Muscle Cramp, Muscle Rigidity, Myositis, Pain.
What kind of drug is methocarbamol?
The FDA classifies methocarbamol as a muscle relaxant. Most muscle relaxants work in the brain and spinal cord rather than on the muscle itself: they damp down the overactive nerve signals and reflexes that keep muscles tense, easing spasms and tightness. Some specialized agents instead act directly on muscle calcium release. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
How long does methocarbamol stay in your system?
The elimination half-life of methocarbamol is about 1 to 2 hours — that is how long the body takes to clear half of a dose. The FDA label reports a mean plasma elimination half-life of 1 to 2 hours in healthy volunteers (about 1.1 hours in a younger group). It names no active metabolite: methocarbamol is cleared by dealkylation, hydroxylation and likely conjugation, and essentially all metabolites leave in the urine, with the label describing no lingering active one. Older adults clear it only slightly more slowly (mean 1.5 hours at a mean age of 69, vs 1.1 hours in a younger group). Kidney impairment barely changes the half-life — in 8 hemodialysis patients it was 1.2 hours vs 1.1 hours in normal subjects — even though total clearance fell about 40%. Liver disease matters most: in 8 patients with alcohol-related cirrhosis, total clearance dropped roughly 70% and the mean half-life rose to about 3.4 hours. Protein binding is 46-50% normally and drops to roughly 40-45% in cirrhosis and 41-43% in older adults. These figures come from immediate-release oral tablets and the IM/IV injection; the label covers no extended-release methocarbamol form. Half-life is not the same as how long a drug test can detect the drug, and it varies with age, kidney and liver function.
Can you take methocarbamol with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run methocarbamol against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is methocarbamol sold under?
We track 3 methocarbamol-containing products in the U.S.: Robaxin, Atmeksi and Methocarbamol. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does methocarbamol come in?
Across the brands we track, methocarbamol is currently marketed as injectable, suspension and tablet, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic methocarbamol?
Yes. Our catalog lists 1 generic methocarbamol product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.
Has methocarbamol been recalled?
The FDA's Enforcement database lists 2 recall records whose product description mentions methocarbamol. The most recent: Methocarbamol Injection USP 1 (Mar 21, 2025). A recall applies to specific lots, not to the drug as a whole — check the record for the affected lot numbers.
What should I avoid while taking methocarbamol?
Other medicines: we hold source-cited interaction answers for Can you take naproxen (Aleve) and methocarbamol (Robaxin) together?. This is what the FDA label and our cited sources say — it is not a complete list. Your pharmacist can check your own combination.
Cite this page
- APA
- pharmaranks. (2026, July 24). Methocarbamol: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/methocarbamol
- MLA
- “Methocarbamol: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/methocarbamol.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for methocarbamol on DailyMed (NIH) ↗.