Two medicines, side by side
Metaxalone vs methocarbamol
Metaxalone and methocarbamol are both labeled for muscle spasms and spasticity. Drugs@FDA records approvals of metaxalone since 1962 and of methocarbamol since 1957. Pharmacies paid $0.452 per metaxalone 800 mg tablet and $0.0395 per methocarbamol 500 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. How each works, in its label's words: Metaxalone, “Mechanism of Action The mechanism of action of metaxalone in humans has not been established, but may be due to general central nervous system (CNS) depression.”; Methocarbamol, “of methocarbamol in humans has not been established, but may be due to general central nervous system (CNS) depression.”
Check it at the source: the metaxalone FDA label on DailyMed (effective January 11, 2023); the methocarbamol FDA label on DailyMed (effective March 17, 2026).
Highlights of the metaxalone record
Metaxalone (Skelaxin) · label of January 11, 2023
Used for
From the label: indicationsMetaxalone is indicated as an adjunct to rest, physical therapy, and other measures for the relief of discomforts associated with acute, painful musculoskeletal conditions. The mode of action of this drug has not been clearly identified, but may be related to its sedative properties. Metaxalone does not directly relax tense skeletal muscles in man.
On the market
- Earliest approval on file
- August 13, 1962
- Generic labelers
- 33 labelers
- Pharmacy cost
- $0.452 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 0
Highlights of the methocarbamol record
Methocarbamol (Robaxin) · label of March 17, 2026
Used for
From the label: indicationsMethocarbamol is indicated as an adjunct to rest, physical therapy, and other measures for the relief of discomfort associated with acute, painful musculoskeletal conditions. The mode of action of methocarbamol has not been clearly identified, but may be related to its sedative properties. Methocarbamol does not directly relax tense skeletal muscles in man.
On the market
- Earliest approval on file
- July 16, 1957
- Generic labelers
- 65 labelers
- Pharmacy cost
- $0.0395 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 6
Source: FDA drug labels via openFDA (Metaxalone label of January 11, 2023, Methocarbamol label of March 17, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do metaxalone and methocarbamol differ on the record?
How each works, in its label's words: Metaxalone, “Mechanism of Action The mechanism of action of metaxalone in humans has not been established, but may be due to general central nervous system (CNS) depression.”; Methocarbamol, “of methocarbamol in humans has not been established, but may be due to general central nervous system (CNS) depression.”
Both are in FDA's class muscle relaxants.
Half-life, in each label's words: Metaxalone, “Thereafter, metaxalone concentrations decline log-linearly with a terminal half-life of 9.0 ± 4.8 hours.”; Methocarbamol, “Pharmacokinetics In healthy volunteers, the plasma clearance of methocarbamol ranges between 0.20 and 0.80 L/h/kg, the …”
Generics: metaxalone since 2010; methocarbamol since 1974 (Drugs@FDA).
| Metaxalone | Methocarbamol | |
|---|---|---|
| Labeled for | Muscle spasms and spasticity | Muscle spasms and spasticity |
| Pharmacologic class | Muscle Relaxant | Muscle Relaxant |
| How it works (label) | Mechanism of Action The mechanism of action of metaxalone in humans has not been established, but may be due to general central nervous system (CNS) depression. | of methocarbamol in humans has not been established, but may be due to general central nervous system (CNS) depression. It has no direct action on the contractile mechanism of striated muscle, the motor end plate or the nerve fiber. |
| Half-life (label) | Thereafter, metaxalone concentrations decline log-linearly with a terminal half-life of 9.0 ± 4.8 hours. | Pharmacokinetics In healthy volunteers, the plasma clearance of methocarbamol ranges between 0.20 and 0.80 L/h/kg, the mean plasma elimination half-life ranges between 1 and 2 hours, and the plasma protein binding … |
| Earliest approval on file (Drugs@FDA) | August 13, 1962 | July 16, 1957 |
| First generic approved | March 31, 2010 | October 22, 1974 |
| Generic labelers (NDC) | 33 labelers | 65 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.452 per tablet (Metaxalone 800 mg tablet) | $0.0395 per tablet (Methocarbamol 500 mg tablet) |
| 12-month price change | -3% | +6% |
| Boxed warning | No | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 0 | 6 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 3,327 | 22,591 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
What do the labels say about using others of their kind?
Metaxalone label, warningsRisks from Concomitant Use with Alcohol or other CNS Depressants The sedative effects of metaxalone and other CNS depressants (e.g., alcohol, benzodiazepines, opioids, tricyclic antidepressants (TCAs)) may be additive.
Methocarbamol label, warningsWARNINGS Since methocarbamol may possess a general CNS depressant effect, patients receiving methocarbamol tablets should be cautioned about combined effects with alcohol and other CNS depressants.
Source: FDA drug labels via openFDA
What next?
- Alternatives to metaxalone
- every medicine labeled for the same conditions