Get the facts on illegal stimulants such as cocaine and methamphetamine.

Stimulants make people more alert, increase their attention, and raise their blood pressure, heart rate, and breathing. Stimulants come in a variety of forms, including amphetamines, cocaine, and methamphetamines. Prescription medications for attention deficit hyperactivity disorder (ADHD) are also often stimulants. Improper use of stimulants (other than when used as prescribed by a doctor) can lead to hostility, paranoia, and even psychotic symptoms. Improper stimulant use can also result in unsafely elevated body temperature, irregular heartbeat, heart failure, and seizures.


Cocaine is a powerful stimulant drug made from the leaves of the South American coca plant. Cocaine is a nervous system stimulant that has the appearance of small, irregularly shaped chunks of a whitish solid. Cocaine can be snorted while in the powered form, injected into the veins after dissolving in water, or smoked. It is also used to produce crack, which is smoked, producing a short, intense high.

Cocaine has two main pharmacological actions. It is both a local anesthetic and a central nervous system stimulant—the only drug known to possess both of these properties. The effects experienced in the early stages of cocaine use include a generalized state of euphoria in combination with feelings of increased energy, confidence, mental alertness, and sexual arousal.

As users come down from their cocaine high, some experience temporary, unpleasant reactions and after effects, which may include restlessness, anxiety, agitation, irritability, and insomnia. With continued, escalating use of cocaine, the user becomes progressively tolerant to the positive effects while the negative effects, such as a dysphoric, depressed state, steadily intensify. Prolonged use may result in adverse physiological effects involving the respiratory, cardiovascular, and central nervous systems. Cocaine use may also result in overdose and death.

Psychologically, the effects of chronic cocaine use are the opposite of the initial effects. These effects can include paranoia, confusion, and an inability to perform sexually. The chronic use of cocaine may also lead to acute adverse physiological effects to the respiratory, cardiovascular, and central nervous systems. Chronic cocaine use can also lead to hospital emergency room visits, prompted by chest pain or palpitations, psychiatric complaints ranging from altered mental states to suicidal ideation, and neurological problems including seizures and delirium.

According to SAMHSA’s 2014 National Survey on Drug Use and Health (NSDUH) (PDF | 3.4 MB):

  • 1.5 million (0.6%) people used cocaine (including crack).
  • People aged 18 to 25 were more than twice as likely to use cocaine compared with other adults.
  • Men (0.8%) were twice as likely to use cocaine compared with women (0.4%).


Methamphetamine (meth) is a stimulant that has a similar chemical structure to amphetamine. Regular methamphetamine is a pill or powder, while crystal methamphetamine takes the form of glass fragments or shiny blue-white “rocks” of different sizes. Meth is taken orally, smoked, injected, or snorted. To increase its effect, users smoke or inject it, or take higher doses of the drug more frequently.

Long-term use of meth has many damaging effects. Chronic meth abusers experience anxiety, confusion, insomnia, paranoia, aggression, visual and auditory hallucinations, mood disturbances, and delusions.

The physiological effects of methamphetamine are generally similar to those of cocaine: increased heart rate, elevated blood pressure and body temperature, and an increased respiratory rate. The psychological effects of methamphetamine, again similar to cocaine, include an increased sense of well-being or euphoria, increased alertness and energy, and decreased food intake and sleep. Methamphetamine has a substantially longer half-life in the body than cocaine (which quickly metabolizes), thus leading to more intense and protracted withdrawal.

Chronic methamphetamine users may have episodes of violent behavior, paranoia, anxiety, confusion, and insomnia. Heavy users show progressive social and occupational deterioration. Research has shown that prolonged methamphetamine use may modify behavior and change the brain in fundamental and long-lasting ways. With time and successful treatment and recovery, the negative effects of methamphetamine on the brain can be diminished or completely reversed.

While findings from NSDUH have indicated an overall decrease in methamphetamine use nationwide, a SAMHSA Drug Abuse Warning Network (DAWN) report showed that hospital emergency room visits related to the use of methamphetamine rose from about 68,000 in 2007 to about 103,000 in 2011. More than 60% of these visits involved the use of methamphetamine with at least one other substance. According to SAMHSA’s 2014 NSDUH (PDF | 3.4 MB), 569,000 Americans used methamphetamine in the past month.

For more information about the treatment of stimulant use disorders, visit the Behavioral Health Treatments and Services topic. For more information about stimulant use disorders, visit the Mental and Substance Use Disorders topic.

Last Updated: 03/02/2016