Duration

The term duration refers to the length of time over which the subjective effects of a psychoactive compound manifest themselves. This can be further broken down into (1) a total duration (2) an onset (3) a peak (4) an offset and (5) after effects. Depending upon the substance consumed, each of these occur in a separate and continuous fashion.

These are listed and described below.

Total

The total duration of a substance can be defined as the amount of time it takes for the effects of a substance to completely wear off into sobriety, starting from the moment the substance is administered.

Onset

The onset phase can be defined as the period of time until the first noticeable changes in perception ("first alert") become apparent.

Come up

The "come up" phase can be defined as the period between the first noticeable changes in perception and the point of highest subjective intensity. This is colloquially known as "coming up."

Peak

The peak phase can be defined as the height of intensity of the substance's effects, as a range rather than a point.

Offset

The offset phase can be defined as the amount of time in between the conclusion of the peak and shifting into a sober state. This is colloquially referred to as "coming down."

After effects

The after effects can be defined as any residual effects which may remain after the experience has reached its conclusion. This is colloquially known as a "hangover" or an "afterglow" depending on the substance and/or the way it is used.