Box 1: “Plateaus” of dextromethorphan toxicity*,2,3.
Plateau 0
Total dose 20mg to 45mg.
You can barely feel it at all, but it relieves cough.
Plateau 0.5
Total dose 45mg to 100mg
Antidepressant effects (especially when stacked with 100mg of Wellbutrin SR)
Plateau 1 (1.5–2.5 mg/kg)
Total intake 100–200 mg (4–6 capsules or 35–60 mL of syrup)
Restlessness, euphoria
Plateau 2 (2.5–7.5 mg/kg)
Total dose 200–500 mg (7–18 capsules or 60–185 mL of syrup)
Exaggerated auditory and visual sensations, closed-eye hallucinations, imbalance
Plateau 3 (7.5–15 mg/kg)
Total dose 500–1000 mg (18–33 capsules or 185–375 mL of syrup)
Visual and auditory disturbances, altered consciousness, delayed reaction times, mania, panic, partial dissociation
Plateau 4 (> 15 mg/kg)
Total dose > 1000 mg (> 33 capsules or > 375 mL of syrup)
Hallucinations, delusions, ataxia, complete dissociation
*Assuming a 75-kg person, 30-mg capsules and 3 mg per millilitre of syrup.
Plateau 0
Total dose 20mg to 45mg.
You can barely feel it at all, but it relieves cough.
Plateau 0.5
Total dose 45mg to 100mg
Antidepressant effects (especially when stacked with 100mg of Wellbutrin SR)
Plateau 1 (1.5–2.5 mg/kg)
Total intake 100–200 mg (4–6 capsules or 35–60 mL of syrup)
Restlessness, euphoria
Plateau 2 (2.5–7.5 mg/kg)
Total dose 200–500 mg (7–18 capsules or 60–185 mL of syrup)
Exaggerated auditory and visual sensations, closed-eye hallucinations, imbalance
Plateau 3 (7.5–15 mg/kg)
Total dose 500–1000 mg (18–33 capsules or 185–375 mL of syrup)
Visual and auditory disturbances, altered consciousness, delayed reaction times, mania, panic, partial dissociation
Plateau 4 (> 15 mg/kg)
Total dose > 1000 mg (> 33 capsules or > 375 mL of syrup)
Hallucinations, delusions, ataxia, complete dissociation
*Assuming a 75-kg person, 30-mg capsules and 3 mg per millilitre of syrup.
by AlienTakeover November 22, 2025
Get the Dextromethorphan HBr plateaus mug.Energy-knowledge plateau: (noun) The point at which energy-knowledge acceleration has reached its limit, and it is no longer possible to find a more efficient energy source that can improve the rate of knowledge acquisition. It emphasizes the idea that the rate of knowledge acquisition has leveled off or reached a maximum point, and that further improvements in energy efficiency will not lead to significant increases in the rate of knowledge acquisition.
The energy-knowledge plateau was reached when no more energy source was found to be more efficient than the current one, limiting the rate of knowledge acquisition and stalling further research.
by Phieyl January 21, 2023
Get the Energy-Knowledge Plateau mug.I.e your bench being stuck on a certain weight e.g 140kg for ages or suddenly going down instead of up
You’ve hit a plateau in your work out
You’ve hit a plateau in your work out
by JayLorenzo July 29, 2022
Get the Plateau mug.The gynecologist said "ma'am you have a San Diego Plateau between your legs and we need to amputate."
by TRUNDEL THE GREAT November 10, 2017
Get the San Diego plateau mug.