Substance Use

What Are the Most Dangerous Drugs?

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What Are the Most Dangerous Drugs?

While many drugs have adverse effects, substances such as fentanyl, heroin, cocaine, methamphetamine, alcohol, benzodiazepines, and ketamine are especially dangerous. This is because these drugs increase the risk of stroke, heart attack, respiratory failure, addiction, memory loss, confusion, drowsiness, and fatigue. Using these drugs can lead to overdose and even death. 

Alcohol or drug addiction can have devastating effects on both the individual and their loved ones. Acknowledging the problem and seeking help can be difficult, but Zinnia Health is here to help. We offer a range of addiction treatment options, including inpatient facilities for those who require intensive care. Call our helpline at (855) 430-9439 to get started.

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Although it is sometimes prescribed for severe pain or as an anesthetic, fentanyl tops the list of the most dangerous drugs because of its potency and potential for deadly overdose.

Fentanyl has been the top cause of drug overdose deaths in the U.S. in recent years. The Centers for Disease Control and Prevention (CDC) reports that, in 2021, synthetic opioids like fentanyl caused 71,238 fatal overdoses among Americans.

According to the Drug Enforcement Administration (DEA), this highly addictive opioid is 50 times more potent than heroin and 100 times more potent than morphine.

That means that even small amounts of the drug can be extremely dangerous. In fact, just two milligrams, equivalent to 10–15 grains of table salt, can be lethal.

There is no way to know how much fentanyl is in a given pill or powder without laboratory testing. Many people consume fentanyl without knowing because it is often sold as counterfeit prescription pills or mixed with other street drugs like cocaine and heroin.

The DEA also reports that a new, alarming trend emerged nationwide in 2022. Dubbed “rainbow fentanyl” by the media, drug cartels appear to have found a new method to sell highly addictive and potentially deadly fentanyl by making it look like candy to children and young people.


Heroin is another opioid drug that can be fatal if taken in overdose amounts. It has no accepted medical use and is highly addictive due to its euphoric effects.

The National Institute on Drug Abuse (NIDA) reports that when it comes to heroin use, developing a tolerance is a common occurrence. This means the body has become accustomed to the drug and requires higher doses to achieve the same results.

This can create a vicious cycle where individuals continue to increase their usage to feel the desired effects. Over time, this can lead to serious health consequences and addiction.

Other potential side effects of using heroin include:

  • Collapsed veins from injecting
  • Infection of the lining and valves of the heart
  • Mental health issues such as depression
  • Respiratory failure
  • Liver and kidney disease
  • Increased risk of infectious diseases such as HIV

Dealing with a dependency on addictive substances can be an overwhelming and isolating experience. Zinnia Health provides compassionate addiction treatment and care. Our team of professionals is available around the clock — call our helpline today at (855) 430-9439.


Cocaine is a stimulant drug that can be snorted, smoked, or injected. It causes a powerful high, but cocaine use also has serious risks.

MedlinePlus states that long-term use of cocaine can also cause severe mental and physical health problems, including:

  • Heart complications, including a rapid heartbeat, high blood pressure, and cardiac arrest
  • Kidney damage
  • Respiratory problems

Symptoms of cocaine intoxication can vary from person to person, but common signs include:

  • Enlarged pupils
  • Excessive sweating
  • Tremors
  • Confusion

A cocaine overdose can cause sudden death, so seek medical attention immediately if you suspect someone is experiencing cocaine intoxication. The best way to avoid a cocaine overdose is to stay away from this drug altogether.


Methamphetamine is a stimulant drug that acts on the central nervous system in a similar way to cocaine. It causes an intense euphoric high but can be extremely dangerous when taken in overdose amounts.

According to the Substance Abuse and Mental Health Services Administration (SAMHSA), methamphetamine, commonly known as meth, is an extremely dangerous drug that alters brain function and accelerates the body’s systems to hazardous levels.

Regular use of meth can cause a range of adverse side effects, including:

  • Anxiety
  • Paranoia
  • Aggression
  • Hallucinations
  • Mood disturbances
  • High blood pressure and heart rate

Methamphetamine increases your risk for stroke, heart attack, and respiratory failure and can lead to death. It is highly addictive, and long-term use can cause severe mental health problems.


Illegal drugs are not the only substances that can cause problems. Alcohol is legal in the United States, but excessive alcohol use poses serious risks.

The National Institute on Alcohol Abuse and Alcoholism (NIAAA) states that drinking in excess, whether it’s a one-time occurrence or done repeatedly over time, can lead to:

  • Addiction
  • Heart disease
  • Liver damage
  • An increased risk of cancer
  • Difficulty processing information and making decisions
  • Depression and anxiety

In the short term, too much alcohol can impair judgment, coordination, and reaction time, leading to injury or death if operating a vehicle.


Benzodiazepines, commonly called “benzos,” are prescription drugs for anxiety and panic disorders. While they can effectively treat these conditions, they also have the potential for abuse and addiction.

The following popular brand names are benzodiazepines:

  • Xanax
  • Valium
  • Ativan

Long-term benzodiazepine use can lead to physical dependence and tolerance, which makes it difficult to stop taking the drug without experiencing withdrawal symptoms. Other risks of benzodiazepine use include:

  • Memory loss
  • Confusion
  • Drowsiness and fatigue
  • Impaired judgment, coordination, and reaction time
  • Difficulty breathing

Only take benzodiazepines as prescribed by a medical professional, and never share them with friends or family. If you or someone you know is struggling with benzodiazepine addiction, it’s vital to seek professional help from an addiction treatment center.


Ketamine is an anesthetic drug that has been used in veterinary and medical settings for decades. However, it is also popular as a recreational drug that can cause powerful psychedelic effects. According to the DEA, the effects of ketamine include:

  • Distorted reality
  • Sensations of calmness and relaxation
  • Pain relief
  • Immobility and amnesia
  • An overwhelming feeling of being out of control
  • Agitation
  • Depression
  • Unconsciousness
  • Hallucinations and flashbacks

Ketamine is extremely dangerous when taken in large doses, and can lead to coma or death. It’s also highly addictive. Those who take ketamine regularly can experience physical dependence and intense cravings for the drug. If you are struggling with ketamine addiction, seek professional help from an addiction treatment center.

Dealing with a substance use disorder can feel isolating, but you’re not alone. Zinnia Health is here to support and help you or a loved one navigate recovery. Our inpatient detox facilities offer comprehensive addiction treatment for legal and illicit drugs, while our outpatient services and group counseling provide assistance in staying sober. Take the first step toward a healthier life and call our helpline anytime, day or night at (855) 430-9439.

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