DXM has notably different effects at different dosage levels. There are 4 distinctive levels, and we call these levels “plateaus”. Most recreational use happens during the first and second plateau. Doses are measured in mg/kg or milligrams per kilogram. So to find your dosage take your weight in kg (pounds divided by 2.2), and then divide it by how many total milligrams your taking. It is hard to describe how any of these plateaus feel, because DXM is one of those things you have to experience to know.
1st Plateau: 1.5-2.5 mg/kg
This is the weakest level. This feels slightly intoxicating, a little light headed. Some music euphoria is noticeable
2nd Plateau: 2.5-7.5 mg/kg
This level is often compared to being stoned and drunk at the same time. When this might seem true, there is also a noticeably strong “mental” high also. You can have trouble talking with slurring, and can have a hard time carrying on an in depth conversation, because your short-term memory can be temporarily impaired. And occasionally you can have mild hallucinations.
3rd Plateau: 7.5-15 mg/kg
This level has strong intoxications and hallucinations. Things can become very confusing as your thinking processes are disturbed. You can sometimes daze-off into your own world, and get lost in your own mind. Trips in this plateau can sometimes be unpleasant.
4th Plateau: +15 mg/kg
This is the strongest level. This is a sub-anaesthetic dose, and can be compared to a high dose of Ketamine. Your mind and body become separated at this level and it can become dangerous psychologically, and physically. Personally I say that you should never have to go this high, it can be very dangerous. But whatever you do, NEVER go past 20 mg/kg (about 2000mg for a 220lb person), this can become very toxic and kill you.