Levomethorphan is a potent opioid analgesic that has never been marketed pharmaceutically. It is the L-stereoisomer of racemethorphan and acts as a prodrug to levorphanol, being demethylated by liver enzymes to its active form. Approximately five times more potent than morphine, levomethorphan carries significant risks of respiratory depression, addiction, and overdose. Due to its metabolism to levorphanol (which has SNRI properties), levomethorphan poses a serious risk of serotonin syndrome when combined with MAOIs, SSRIs, SNRIs, or other serotonergic drugs. It is a Schedule II controlled substance in the United States.
Levometorfan molecular structure diagram from the DrugsPRO substance library.
Also known as: Lvm, Ro 1-5470/6, L-methorphan, Levometorfano, Levomethorphanum
Classification
Chemical: Morphinan
Chemical: Opioid
Psychoactive: Depressant
Tag: Research-Chemical
Effects
Pain Relief
Sedation
Respiratory Depression
Itching
Nausea
Physical Euphoria
Euphoria
Cognitive Euphoria
Anxiety Suppression
Compulsive Redosing
Dissociation
Dysphoria
Dulled Perception
Decreased Libido
Increased Music Appreciation
Internal Hallucination
Cognitive Dysphoria
Sound Amplification
Routes of Administration
Oral
Dosage
Threshold: 1-2 mg
Light: 2-5 mg
Common: 5-10 mg
Strong: 10-15 mg
Heavy: 15+ mg
Duration
Onset: 0.33-1 h
Comeup: 0.5-1.5 h
Peak: 1-3 h
Offset: 4-6 h
After Effects: 6-10 h
Total Duration: 4-8 h
Harm Reduction
Check interactions before mixing substances, pay attention to dose spacing and hydration, and treat all dosage guidance as approximate rather than guaranteed safe.
Sources
Substance data is aggregated from the following public harm-reduction and reference sources.
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Levomethorphan - DrugsPRO stoffveiledning
Levomethorphan: Levomethorphan is a potent opioid analgesic that has never been marketed pharmaceutically. It is the L-stereoisomer of racemethorphan and acts as a prodrug to levorphanol, being demethylated by liver enzymes to its active form. Approximately five times more potent than morphine, levo