10 Types of Drugs Used for Medicinal (and Illicit) Purposes

Prescription drugs are medications approved for medical use, like treating high blood pressure or attention deficit hyperactivity disorder. They’re safe when taken as directed, but misuse or combining multiple drugs increases the risk of negative effects and even death.

CNS depressants slow brain activity. Common benzodiazepines fall into this category and treat sleep disorders, panic attacks or muscle spasms.

At high doses, they can cause slurred speech and slow breathing—and long-term use can lead to physical dependence. Combining benzodiazepines with other substances raises the chance of fatal overdoses.

Stimulants speed up nervous system activity, increasing energy, alertness and blood pressure. They’re both a stimulant for medical use (like ADHD medications) and a recreational drug of abuse (like crack cocaine).

Excessive doses can lead to kidney failure and panic attacks, while repeated use may result in addiction.

Opioid drugs target opioid receptors in the brain to relieve pain. Prescription forms include synthetic opioids for severe pain, while illicit drugs like heroin drive opioid overdose risks.

Long-term use can cause physical dependence, withdrawal symptoms and intense cravings.

Dissociative drugs like ketamine and nitrous oxide distort perception of sight and sound. They alter brain functions, creating feelings of detachment from the body. These drugs affect mental health, sometimes leading to psychological dependence.

Hallucinogens—including lysergic acid diethylamide (LSD) and "magic" mushrooms—change perception, mood and thought. They can trigger altered perception and unusual sensory experiences.

While some study their potential for mental health treatment, they can also cause dangerous reactions.

Inhalants include paint thinners and other substances inhaled for quick effects. They depress the central nervous system, causing dizziness and euphoria.

Chronic use can lead to severe health problems, including brain damage and even death.

Anabolic steroids are synthetic versions of testosterone. Medically, they treat conditions like delayed puberty. Illegally, they’re used to build muscle mass, but they increase risk of heart disease, liver damage and mental health issues.

Designer drugs are synthetic substances engineered to mimic illegal drugs. Bath salts and liquid ecstasy fall into this category.

Because they’re often unregulated, their effects can be unpredictable, leading to severe health consequences.

This group includes specific drugs often misused recreationally: cocaine, methamphetamine, and prescription opioids. Abuse of these highly addictive substances leads to "meth mouth," severe withdrawal symptoms, and increased risk of overdose.

We created this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.