About Rohypnol
Rohypnol is a fast acting sedative, and is also known as the "date rape drug". It comes in the form of a small white pill. In its normal low dose, Rohypnol has 7 times the sedative effect of Valium. 
Use
The pill is small and can be swallowed. Illicitly, it is typically slipped in a drink and dissolved.
Street names
Roofie, The forget me pill, R2, rope
Risks
Higher doses can produce anterograde amnesia (a form of memory loss where new events are not transferred to long-term memory), loss of muscle control, and loss of consciousness. Can also cause a reduction in blood pressure, visual disturbances, dizziness and confusion, urinary retention, or aggressive behavior.
Warning
Rohypnol can be addictive with chronic use.

Never leave a drink unattended!