Immediately after smoking the drug or injecting it intravenously, the user experiences an intense rush or "flash" that lasts only a few minutes and is described as extremely pleasurable. Snorting or oral ingestion produces euphoria - a high but not an intense rush. Snorting produces effects within 3 to 5 minutes, and oral ingestion produces effects within 15 to 20 minutes.
As with similar stimulants, methamphetamine most often is used in a "binge and crash" pattern. Because tolerance for methamphetamine occurs within minutes - meaning that the pleasurable effects disappear even before the drug concentration in the blood falls significantly - users try to maintain the high by binging on the drug.
In the 1980's, "ice," a smokable form of methamphetamine, came into use. Ice is a large, usually clear crystal of high purity that is smoked in a glass pipe like crack cocaine. The smoke is odorless, leaves a residue that can be resmoked, and produces effects that may continue for 12 hours or more.
Short-term Effects Can Include:
- Increased attention and decreased fatigue
- Increased activity
- Decreased appetite
- Euphoria and rush
- Increased respiration
Long-term Effects Can Include:
- Dependence and addiction psychosis - paranoia, hallucianations, mood disburbances, repetitive motor activity
- Weight loss