Speed is a central nervous system stimulant that can cause increased alertness, euphoria, increased heart rate and blood pressure, insomnia, and loss of appetite.
Stimulants such as speed may be used to treat attention-deficit hyperactivity disorder and narcolepsy, and for weight control.
Many of the drugs referred to as speed are quite accessible, and all are highly addictive. According to the 2015 National Survey on Drug Use and Health, an estimated 1.7 million people ages 12 and older had used stimulants such as speed non-medically in the past month. This number doesn’t even include the 897,000 methamphetamine users.