Metaxalone

A muscle relaxant, FDA-approved for short-term relief of discomfort from acute, painful musculoskeletal conditions in people 13 and older.

psilodex.org/m/metaxalone · data v2026.10.05

Clinical contraindication: None listed; No label contraindication covering psilocybin was found. This is not a finding that the combination has been shown to be without risk.
Psilocybin evidence: No psilocybin data
Half-life: 7.6–11.1 h; Approximate, in adults. Source under Interaction below.

Named in state rules?

Not namedColorado

Not namedOregon

PendingNew Mexico

Cite asPsilodex, “Metaxalone”, v2026.10.05. psilodex.org/m/metaxalone

Clinical data and state rules are separate facts. Both are shown; neither is a decision.

What it is used for

FDA status

FDA-approved

FDA-approved for

Acute, painful musculoskeletal conditions (with rest and physical therapy)

Sources [1]

01 Interaction with psilocybin

Not studied with psilocybin; it is sedating and its label reports serotonin syndrome with serotonin-boosting drugs, so added effects are possible.

Detail Metaxalone has not been studied with psilocybin. Its label reports serotonin syndrome with other serotonergic (serotonin-boosting) drugs and in overdose. No case with psilocybin has been reported, so this is theoretical. Its CNS-depressant (sedating) effects may add sedation to psilocybin's effects. Sources [1]

Human data with psilocybin: No psilocybin data; based on how it works and its label
Half-life: 7.6–11.1 h (mean, men to women) (FDA label, checked 2026-10-04)

Evidence types on this record

No psilocybin dataNo psilocybin data: no human data with psilocybin or another classic psychedelic; the text draws on the medication's own pharmacology and its label or reference facts

02 Pharmacology relevant to psilocybin

2 listed · counted on reports

Sedating or CNS depressant: Slows the central nervous system: drowsiness, slower reactions and impaired coordination, and slowed breathing at high doses. Effects add with other sedating substances. Sources [1]
Serotonergic: Increases serotonin activity, for example by blocking its reuptake or releasing it. Psilocybin acts on serotonin receptors, so effects can add together. With antidepressant use, the psilocybin response can be weaker. Sources [1]

03 State rules

Plain-language summary · official text governs

CO4 CCR 755-1

Not named

No provision names this medication or its class.

Colorado · checked 2026-10-04

OROAR 333-333

Not named

No provision names this medication or its class.

Oregon · checked 2026-10-04

NM7.35.3 NMAC (proposed)

Pending

New Mexico's clinical rules (proposed 7.35.3 NMAC) are not final. No provision naming this medication has been found.

New Mexico · checked 2026-10-04

04 Conditions to ask about

None linked

No condition named in state rules is linked to this medication.

05 Sources

METAXALONE tablets (Amneal) · FDA label (DailyMed) — Serotonergic: 5.1 "Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of metaxalone (within the recommended dosage range) and other serotonergic drugs" | Sedating or CNS depressant: 5.2 "Because of its central nervous system (CNS) depressant effects, metaxalone may impair mental and/or physical abilities required for performance of hazardous tasks" | 12.3 "The mean half-life was 11.1 hours in females and 7.6 hours in males."

Record history

v2026.10.02First published.
2026-10-04Last reviewed against its sources.

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