Two medicines, side by side
Chlorzoxazone vs methocarbamol
Chlorzoxazone and methocarbamol are both labeled for muscle spasms and spasticity. Drugs@FDA records approvals of chlorzoxazone since 1958 and of methocarbamol since 1957. Pharmacies paid $0.210 per chlorzoxazone 500 mg tablet and $0.0395 per methocarbamol 500 mg tablet (NADAC, October 7, 2026).
Check it at the source: the chlorzoxazone FDA label on DailyMed (effective September 5, 2023); the methocarbamol FDA label on DailyMed (effective March 17, 2026).
Highlights of the chlorzoxazone record
Chlorzoxazone (Parafon Forte Dsc) · label of September 5, 2023
Used for
From the label: indicationsChlorzoxazone 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 this drug has not been clearly identified, but may be related to its sedative properties. Chlorzoxazone does not directly relax tense skeletal muscles in man.
On the market
- Earliest approval on file
- August 15, 1958
- Generic labelers
- 19 labelers
- Pharmacy cost
- $0.210 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 2
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 (Chlorzoxazone label of September 5, 2023, Methocarbamol label of March 17, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do chlorzoxazone and methocarbamol differ on the record?
Both are in FDA's class muscle relaxants.
Generics: chlorzoxazone since 1981; methocarbamol since 1974 (Drugs@FDA).
| Chlorzoxazone | Methocarbamol | |
|---|---|---|
| Labeled for | Muscle spasms and spasticity | Muscle spasms and spasticity |
| Pharmacologic class | Muscle Relaxant | Muscle Relaxant |
| How it works (label) | n/a | 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) | n/a | 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 15, 1958 | July 16, 1957 |
| First generic approved | October 6, 1981 | October 22, 1974 |
| Generic labelers (NDC) | 19 labelers | 65 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.210 per tablet (Chlorzoxazone 500 mg tablet) | $0.0395 per tablet (Methocarbamol 500 mg tablet) |
| 12-month price change | -5% | +6% |
| Boxed warning | No | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 2 | 6 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 1,296 | 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?
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 chlorzoxazone
- every medicine labeled for the same conditions