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Two medicines, side by side

Metaxalone vs cyclobenzaprine

Metaxalone and cyclobenzaprine are both labeled for muscle spasms and spasticity. Drugs@FDA records approvals of metaxalone since 1962 and of cyclobenzaprine since 1977. Pharmacies paid $0.452 per metaxalone 800 mg tablet and $0.0171 per cyclobenzaprine 10 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. Cyclobenzaprine's other strengths are brand-only: $29.61 per tablet (Tonmya 2.8 mg tablet sl).

Check it at the source: the metaxalone FDA label on DailyMed (effective January 11, 2023); the cyclobenzaprine FDA label on DailyMed (effective February 21, 2025).

Highlights of the metaxalone record

Metaxalone (Skelaxin) · label of January 11, 2023

Used for

From the label: indications

Metaxalone 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 cyclobenzaprine record

Cyclobenzaprine (Flexeril) · label of February 21, 2025

Used for

From the label: indications

Cyclobenzaprine hydrochloride tablets, USP are indicated as an adjunct to rest and physical therapy for relief of muscle spasm associated with acute, painful musculoskeletal conditions. Improvement is manifested by relief of muscle spasm and its associated signs and symptoms, namely, pain, tenderness, limitation of motion, and restriction in activities of daily living. […]

On the market

Earliest approval on file
August 26, 1977
Generic labelers
59 labelers
Pharmacy cost
$0.0171 per tablet

Supply and safety

Shortage
No current entry
Recalls
5

Source: FDA drug labels via openFDA (Metaxalone label of January 11, 2023, Cyclobenzaprine label of February 21, 2025); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)

How do metaxalone and cyclobenzaprine differ on the record?

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.”; Cyclobenzaprine, “Cyclobenzaprine is eliminated quite slowly, with an effective half-life of 18 hours (range 8 to 37 hours; n=18); …”

Generics: metaxalone since 2010; cyclobenzaprine since 1988 (Drugs@FDA).

MetaxaloneCyclobenzaprine
Labeled forMuscle spasms and spasticityMuscle spasms and spasticity, Nerve pain and fibromyalgia
Pharmacologic classMuscle RelaxantMuscle 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.n/a
Half-life (label)Thereafter, metaxalone concentrations decline log-linearly with a terminal half-life of 9.0 ± 4.8 hours.Cyclobenzaprine is eliminated quite slowly, with an effective half-life of 18 hours (range 8 to 37 hours; n=18); plasma clearance is 0.7 L/min.
Earliest approval on file (Drugs@FDA)August 13, 1962August 26, 1977
First generic approvedMarch 31, 2010February 29, 1988
Generic labelers (NDC)33 labelers59 labelers
Pharmacy cost (NADAC, each one's most listed form; strengths differ)$0.452 per tablet (Metaxalone 800 mg tablet)$0.0171 per tablet (Cyclobenzaprine 10 mg tablet)
12-month price change-3%-10%
Boxed warningNoNo
Shortage nowNo current entryNo current entry
Recalls recorded05
FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used)3,32750,442
DEA schedulenonenone

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, warnings

Risks 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.

Cyclobenzaprine label, warnings

If concomitant treatment with cyclobenzaprine hydrochloride and other serotonergic drugs is clinically warranted, careful observation is advised, particularly during treatment initiation or dose increases (see PRECAUTIONS :

Source: FDA drug labels via openFDA

What next?

Alternatives to metaxalone
every medicine labeled for the same conditions