Health Effects of Stimulants

First published 2009. To view the latest Heads Up content, click here.

Stimulants are a class of drugs that “stimulate” the body’s central nervous system, which includes the brain and spinal cord. They increase the levels of catecholamines—a family of brain chemicals that includes dopamine. These chemicals are used in the brain processes to signal reward and motivation. By increasing catecholamine levels, stimulants can temporarily increase a person’s energy level and alertness. Stimulants may also cause other changes in the body. The effects vary according to the specific drug, the amount of the drug, and how the drug is taken. For instance, stimulants that are snorted or injected have more immediate effects than drugs that are swallowed.


Stimulants include the caffeine found in coffee, medications such as methylphenidate (Ritalin®, Concerta®), and abused drugs, such as methamphetamine and cocaine. Stimulants can have useful properties—under the right circumstances.  For example, doctors use some stimulants to treat disorders such as Attention-Deficit/Hyperactivity Disorder (ADHD). However, when abused, stimulants can pose serious health risks to your brain and your body. Read on to find out the effects of the following stimulants:

  • Cocaine
  • Prescription stimulants, such as amphetamines and methylphenidate
  • Methamphetamine (“meth”)
  • MDMA (“ecstasy”)
  • Nicotine


Cocaine, sometimes called “coke” or “blow,” comes in powder or crystal form. It can be snorted, smoked, or injected. Cocaine blocks the dopamine transporter that is responsible for recycling dopamine at the end of a signal between brain cells (called neurons).  When this happens, dopamine builds up in the gap between neurons (called the synapse) and overstimulates the neurons. That can cause a powerful, but temporary sense of euphoria.

  • Cocaine is sometimes used during nose, mouth, or eye surgery, since it constricts blood vessels and helps to control blood flow during the surgery.  Cocaine is also a local anesthetic—which means that it can help to numb an area of the body.

  • Cocaine can speed up heart rate and cause the heart to lose its natural rhythm. In rare cases, this can lead to a heart attack.
  • Cocaine constricts blood vessels, which forces the heart to work harder to pump blood.
  • Cocaine can cause chest pain and difficulty breathing.
  • Cocaine can cause a potentially dangerous increase in body temperature.
  • Regularly snorting cocaine can lead to loss of sense of smell, nosebleeds, and problems with swallowing. The overall irritation can lead to a chronically inflamed, runny nose.
  • Repeated use or high doses of cocaine can cause irritability, restlessness, panic attacks, and paranoia.


Stimulant medications are often prescribed to treat individuals with Attention-Deficit/Hyperactivity Disorder (ADHD). For example, Adderall® is a brand-name amphetamine medication, and Ritalin® and Concerta® are brand-names for methylphenidate. Like all stimulants, these medications increase dopamine levels in the brain. When used according to a doctor’s orders, the drugs can help a person with ADHD to focus and reduce their ADHD symptoms. However, when taken in high doses, or in ways other than as prescribed (or by someone for whom the drug was not prescribed), stimulant medications can have harmful effects. The effects are similar to other drugs of abuse, and can lead to addiction.

  • Prescription stimulants can reduce ADHD symptoms and increase focus and attention in people who have ADHD.

  • Abuse of prescription stimulants can increase heart rate, blood pressure, and body temperature.
  • Stimulant medications can decrease sleep and appetite, and abuse can lead to malnutrition and its consequences.


Methamphetamine, often called “meth,” comes in a crystalline powder that can be smoked, snorted, or injected. Like other stimulants, meth increases dopamine levels and can increase energy and cause a temporary feeling of euphoria. However, methamphetamine stays in the body longer than some of the other stimulants, and therefore can have more harmful effects on the central nervous system.

  • A doctor may prescribe methamphetamine in low doses to treat ADHD or narcolepsy, a disorder in which a person experiences extreme sleepiness during the day and may fall asleep uncontrollably. However, due to the many serious harmful effects of methamphetamine, and the availability of other medications with lower risk, doctors rarely prescribe methamphetamine.

  • Methamphetamine can cause rapid or irregular heartbeat and increased blood pressure. These effects can lead to a heart attack.
  • Methamphetamine can increase body temperature. In rare cases, hyperthermia can lead to liver, kidney, and cardiovascular failure and death.
  • Methamphetamine can cause the gums to decay and the teeth to rot, a condition known as “meth mouth.”
  • Long-term use of methamphetamine can cause changes to the structure of the brain in areas involved with memory and emotions. This can lead to memory problems and erratic behavior.
  • Long-term use of methamphetamine can cause paranoia, hallucinations, and violent behavior.


MDMA, or “ecstasy,” comes in the form of a pill. In addition to affecting dopamine levels in the brain, MDMA affects the nerve cells in the brain that use the chemical serotonin to communicate with other nerve cells. Like other stimulants, the effects of MDMA can include increased energy and feelings of well-being.

  • No medical uses.

  • MDMA can increase heart rate and blood pressure.
  • MDMA can increase body temperature. In rare cases, this can lead to liver, kidney, and cardiovascular failure and death.
  • MDMA can cause muscle tension and involuntary teeth clenching.
  • Repeated MDMA use can disrupt sleep, memory, and mood (at least temporarily)


Nicotine is a highly addictive stimulant found in cigarettes and chewing tobacco. Like other stimulants, nicotine increases dopamine in the brain. It also stimulates the body’s adrenal glands to release epinephrine (also called adrenaline). Epinephrine is normally released when a person experiences a stressful situation. Epinephrine stimulates the central nervous system, increasing heart rate, breathing rate, and blood pressure.

  • Medicinal nicotine in the form of a patch or gum is used to help people stop smoking and using other tobacco products. The nicotine in these products helps reduce the person’s withdrawal symptoms.

  • Nicotine increases heart rate and blood pressure.
  • Nicotine increases blood sugar levels.
  • Chewing or smoking tobacco discolors teeth and causes tooth decay.
  • Chewing or smoking tobacco can cause cancer of the lungs, mouth, and throat.


Getting Help


If you or someone you know is abusing or addicted to stimulants, there are many drug treatment programs and support groups that can help. Currently behavioral therapies are the most effective approach to treating stimulant addiction. Treatment programs seek to engage people in therapy, reward abstinence, and/or to help change the way a drug user thinks and behaves when faced with situations that may lead to drug use.


With the exception of nicotine (tobacco addiction), there are no medications approved to treat stimulant addiction. However, scientists are actively working in this area.  They are studying different types of medications to help prevent cravings, reduce relapse, and address some of the mood and other problems that people addicted to stimulants often have.  Scientists believe that a combination of medications (when they become available) and behavioral therapies will likely prove to be the most effective approach to treating stimulant addiction in the future.

For more facts about stimulants and other drugs, visit

Learn more about stimulant addiction.

(Header image credit: © Alto Photography/Veer)

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