Levomethorphan
Aliases: Lvm, Ro 1-5470/6, L-methorphan
Categories
Summary
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.
Dose Information
Light
Common
Strong
Heavy
Onset, Duration & After-effects
| ROA | Onset | Comeup | Peak | Offset | After Effects |
|---|---|---|---|---|---|
| Oral | 20-60 min | 30-90 min | 1-3 hrs | 4-6 hrs | 2-4 hrs |
Tolerance
Build-up
develops within days of regular use; analgesic tolerance faster than respiratory depression tolerance
Reset
7–14 days for partial reset; full reset may take weeks — tolerance loss greatly increases overdose risk
Effects
Positive
- Pain relief
- Physical euphoria
- Analgesia
Negative
- Respiratory depression
- Itching
- Nausea
- Dry Mouth
- Sedation
- Itchiness
- Relaxant
Positive
- Euphoria
- Cognitive euphoria
- Anxiety suppression
- Mood lift
- Cognitive Euphoria
Negative
- Compulsive redosing
- Dysphoria
- Constipation
- Dizziness
- Dissociation
Positive
- Visual geometry
Negative
- Appetite suppression
- Decreased Libido
- Appetite Suppression
- Double vision
- Spatial disorientation
- Dulled perception
- Internal hallucination
- Internal hallucinations
- Visual and auditory hallucinations