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Updated on July 27, 2021

Most Addictive Drugs in the World

What Makes a Drug Addictive?

Most drugs affect the brain’s reward system, causing euphoria and flooding the brain with the neurotransmitter dopamine. Increased dopamine levels cause the reinforcement of pleasurable but unhealthy behaviors like taking drugs, which leads people to continue the behavior.

Why Do People Get Addicted to Drugs?

As a person uses drugs, the brain adapts by reducing the ability of cells in the reward center to respond to it. When this change occurs, a person feels less high than the high they felt when first taking the drug—an effect known as tolerance. 

An increased tolerance might make someone take more of the drug to achieve the same high and cause them to become less and less able to derive pleasure from other things they once enjoyed. An increased tolerance will also make someone experience unpleasant withdrawal symptoms when they don’t take the drug. At this point, people often use drugs or alcohol to keep from feeling bad rather than for their pleasurable effects.

Repeated use of drugs can also damage the essential decision-making center of the brain, known as the prefrontal cortex. When the frontal cortex isn’t working correctly, people can’t decide to stop taking the drug—even when faced with severe consequences. 

Find Help For Your Addiction

You don’t have to overcome your addiction alone. Professional guidance and support is available. Begin a life of recovery by reaching out to a specialist today.

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7 Most Addictive Drugs in the World

Some of the most addictive drugs in the world include:

1. Opioids

Opioids are a class of drugs made from the opium poppy plant. These addictive substances are potent painkillers that block pain signals between the brain and the body. Other medical uses for opioids include anesthesia, suppression of diarrhea, replacement therapy for opioid use disorder, reversing opioid overdose, and suppressing coughs.

List of Addictive Opioids:

Codeine is a pain reliever used to treat mild to moderately severe pain. Codeine is also used to reduce coughing. Codeine is available as a single-ingredient product, combined with acetaminophen or aspirin, and in some cough and cold medications.


Hydrocodone is a semi-synthetic opioid that acts as an analgesic (pain reliever) and an antitussive (cough suppressant). Hydrocodone can also produce feelings of euphoria and is a prevalent drug of abuse.


Oxycodone is a semi-synthetic opioid drug prescribed for pain as Tylox®, Percodan®, and OxyContin®. This drug creates feelings of relaxation and euphoria and is often abused. Street Names for oxycodone include Hillbilly Heroin, Kicker, OC, Ox, Roxy, Perc, Oxy. 


Meperidine hydrochloride, often prescribed as Demerol, is a drug used to treat moderate to severe pain. 


Fentanyl is a synthetic opioid that treats severe pain, typically advanced cancer pain. Fentanyl is 50 to 100 times more potent than morphine. Fentanyl is often sold through illegal drug markets for its heroin-like effect. 


Methadone is a medication approved by the Food and Drug Administration (FDA) to treat opioid use disorder (OUD). Methadone is a long-acting full opioid agonist and a schedule II controlled medication.

When taken as prescribed, methadone is safe and effective. Methadone helps individuals achieve and sustain recovery and to reclaim active and meaningful lives.

Side Effects of Opioids

Common side effects of opioid use include:

  • Sedation
  • Dizziness
  • Nausea
  • Vomiting
  • Constipation
  • Physical dependence
  • Tolerance
  • Respiratory depression
Dangers of Opioids

Dangers of opioid use include:

  • Delayed gastric emptying
  • Hyperalgesia
  • Immunologic and hormonal dysfunction
  • Muscle rigidity
  • Myoclonus
  • Addiction
  • Accidental overdose death

An average of 128 Americans die every day from an opioid overdose. 

2. Heroin

Heroin is a type of opioid drug made from morphine. Heroin appears as a white or brown powder, or a black sticky substance known as black tar heroin. Heroin users inject, sniff, snort, or smoke heroin. Some street names for heroin are horse, smack, and hell dust.

Side Effects of Heroin

Side effects of heroin use include:

  • A surge of pleasure or euphoria
  • Dry mouth
  • Warm flushing of the skin
  • Heavy feeling in the arms and legs
  • Nausea and vomiting
  • Severe itching
  • Clouded mental functioning
  • Going “on the nod,” a back-and-forth state of being conscious and unconscious
Dangers of Heroin 

The dangers of heroin use include developing any of the following health consequences:

  • Heroin addiction
  • Higher likelihood of contracting HIV or other bloodborne diseases 
  • Insomnia
  • Collapsed veins 
  • Damaged tissue inside the nose
  • Infection of the heart lining and valves
  • Abscesses 
  • Liver and kidney disease
  • Lung complications, including pneumonia
  • Mental illness such as depression and antisocial personality disorder
  • Sexual dysfunction (for men)
  • Irregular menstrual cycles (for women)
  • Accidental overdose death

3. Cocaine

Cocaine is a stimulant drug made from the coca plant. Cocaine looks like a fine, white powder, or a crystallized rock. Popular nicknames for cocaine include Coke, Blow, Crack, Rock, and Snow.

Side Effects of Cocaine
  • Extreme happiness and energy
  • Mental alertness
  • Hypersensitivity to light, sound, and touch
  • Irritability
  • Paranoia
  • Constricted blood vessels
  • Dilated pupils
  • Nausea
  • Raised body temperature and blood pressure
  • Fast or irregular heartbeat
  • Tremors and muscle twitches
  • Restlessness and insomnia
Dangers of Cocaine 

Dangers of cocaine use include:

  • Loss of smell
  • Nosebleeds
  • Problems with swallowing
  • Cough
  • Asthma
  • Respiratory distress
  • Psychosis
  • Higher risk of lung infections like pneumonia
  • Higher risk for contracting HIV, hepatitis C, and other bloodborne diseases (when injected)
  • Higher likelihood of engaging in risky sexual behavior and contracting sexually transmitted disease
  • Cardiac arrest and death

4. Alcohol

Ethyl alcohol, or ethanol, is an ingredient found in wine, beer, and liquor. Alcohol belongs to a class of drugs called depressants that slow the functioning of the body’s systems.

Side Effects of Alcohol

The side effects of alcohol use include:

  • Impaired judgment
  • Slurred speech
  • Drowsiness
  • Vomiting and diarrhea
  • Distorted vision and hearing
  • Decreased coordination
  • Short-term memory loss or blackouts
  • Coma
  • Death
Dangers of Alcohol 

Alcohol abuse increases the risk of developing several health consequences, including:

  • Alcohol addiction
  • Injuries or violence
  • Alcohol poisoning
  • Higher likelihood of engaging in risky sexual behaviors, which can result in unintended pregnancy or sexually transmitted diseases, including HIV
  • Higher risk of miscarriage, stillbirth, or fetal alcohol syndrome among pregnant women
  • High blood pressure or heart disease
  • Liver disease
  • Digestive problems
  • Cancer 
  • A weakened immune system
  • Learning and memory problems
  • Mental illness, including depression and anxiety

5. Nicotine

Nicotine is a powerful stimulant drug that speeds up the messages traveling between the brain and body. It is the primary psychoactive ingredient in tobacco products.

Side Effects of Nicotine

The following side effects may occur when using tobacco products that contain nicotine:

  • Dizziness
  • Headache
  • Nausea
  • Abdominal cramps
  • Vomiting or weakness
  • Increase in heart rate
  • Increased ability to concentrate
  • Relaxation
  • Temporary reduction in the urge to smoke
  • Coughing
  • Bad breath
  • Tingling and numbness in fingers and toes
  • Reduced appetite
Dangers of Nicotine

When a large amount of nicotine is taken, users may experience the following dangerous effects:

  • Confusion
  • Feeling faint
  • Seizures
  • Fast breathing
  • Respiratory arrest and death

6. Stimulants (Uppers)

Stimulants are a type of drug that speed up the body’s systems.

List of Addictive Stimulants 

Adderall is a prescription drug that is used to treat attention-deficit hyperactivity disorder (ADHD). Adderall is also used illicitly as a study aid, to stay awake, and to suppress appetites.


Concerta is another prescription drug that’s used to treat attention deficit hyperactivity disorder (ADHD).


Ritalin is a prescription medicine used to treat attention deficit hyperactivity disorder (ADHD) and narcolepsy.


Ecstasy is the street name for 3,4-methylenedioxymethamphetamine (MDMA). It is chemically similar to stimulants and hallucinogens, producing feelings of increased energy, pleasure, emotional warmth, and distorted sensory and time perception.

People who use Ecstasy usually take it as a capsule or tablet, though some swallow it in liquid form or snort the powder. 


Methamphetamine is a stimulant that speeds up the body's systems. It is prescribed medically to treat obesity and ADHD as Desoxyn.  

Meth is also used as a recreational drug and is smoked, snorted, or injected. Street names for meth include Speed, Ice, Shards, Bikers Coffee, Stove Top, Tweak, Yaba, Trash, Chalk, Crystal, Crank, Shabu.


Dexedrine sulfate is a long- or short-acting capsule, taken orally, that is primarily used to treat attention deficit hyperactivity disorder (ADHD). Dexedrine is also used to treat narcolepsy.

Side Effects of Stimulants

Common side effects of stimulant use include:

  • Feelings of euphoria 
  • Increased heart rate and blood pressure
  • Increased alertness
  • Increased talkativeness
  • Reduced appetite
Dangers of Stimulants

The dangers of taking high doses of stimulants include:

  • Anxiety
  • Tension
  • Increased body temperature
  • Nausea
  • Tremor
  • Seizures
  • Coma
  • Stroke
  • Overdose
  • Death

7. Barbiturates (Downers)

Barbiturates are a type of drug used to depress the central nervous system (CNS). Barbiturates are generally only used to treat severe and extreme cases of insomnia, but they can also be used to control seizures and as an adjunct to anesthesia.

List of Addictive Barbiturates 

Xanax is used to treat anxiety, panic disorder, and anxiety associated with depression. 


Valium is used to treat anxiety, muscle spasm, alcohol withdrawal, and sedatives before surgery or to treat seizures. 


Klonopin is used to treat the symptoms of seizures and panic disorder. 


Ativan is used to treat the symptoms of anxiety disorders.


Librium is used to treat the symptoms of anxiety. 

Sleeping Pills 

“Sleeping pills” is a term that refers to prescription or over-the-counter medicines that help users fall or stay asleep. Sleeping pills belong to a type of drugs called hypnotics, and can have serious side effects if abused.


Phenazepam is a benzodiazepine drug that is used to treat some types of mental illness. Some of the concerning side effects of phenazepam include loss of coordination, drowsiness, and amnesia.

Side Effects of Barbiturates

Common side effects of barbiturates include:

  • Relief of anxiety
  • Drowsiness
  • Headache
  • Low blood pressure (hypotension)
  • Nausea
  • Sedation
  • Skin rash
  • Irritability
  • Lack of inhibition
  • Impairment of memory, judgment, and coordination
Dangers of Barbiturates

Serious side effects of barbiturates include:

  • Abnormally slow breathing or breathing cessation
  • Coma
  • Confusion
  • Fainting
  • Hallucinations
  • Agranulocytosis
  • Erythroderma
  • Liver injury
  • Megaloblastic anemia
  • Stevens-Johnson syndrome
  • Paranoia and suicidal thought
  • Overdose

Don't Let Addiction Control You.

You can overcome any struggle – including your substance abuse problem - if you have the right help from qualified professionals. Give yourself the freedom of recovery by turning things around today.

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Symptoms of Substance Use Disorder (SUD)

Symptoms of substance use disorder (SUD) include one or more of the following symptoms within 12 months:

  • Recurring substance use that causes the user to fail to fulfill significant role obligations at work, school, or home 
  • Regular substance use in situations in which it is physically hazardous such as driving or operating heavy machinery
  • Legal problems caused by substance use
  • Continuing to use a substance despite social or interpersonal problems caused or made worse by the effects of the substance 

Addiction Treatment Options

Drug addiction treatment options include inpatient, outpatient, partial hospitalization, or detox programs. Drug addiction therapies can consist of medications, behavioral therapies, or their combination. The right treatment program depends on the patient’s individual needs and on the types of drugs they use.

Address Your Addiction

Don't let addiction control you. Give yourself the power to get help for your addiction today.

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