How long do the effects of speed last?

The effects of speed (amphetamine) can last from 4 to 6 hours, depending on the dosage and individual metabolism. Users may experience increased energy, alertness, and euphoria during this period. However, the duration can vary based on factors such as tolerance, method of use, and individual physiology. After the initial effects wear off, users may experience a "crash" characterized by fatigue and mood changes.