The most dangerous drugs not only include controlled substances like opioids, but common over-the-counter treatments like Tylenol.

Article at a Glance:

  • Many drugs can be dangerous, even if they are over-the-counter remedies or available by prescription.
  • Acetaminophen was found to be the most dangerous drug available in a recent report.
  • Controlled substances like opioids and cocaine also top the list of dangerous drugs.

Dangerous Drugs

Any drug that creates a chemical imbalance in a person’s body or causes euphoric effects can be dangerous. Many drugs will interact with the brain and body to release certain feel-good chemicals such as endorphins, dopamine and serotonin. Releasing these chemicals creates a pleasurable feeling that can result in the body needing the drug to maintain a necessary chemical balance. This forms a physical dependence on the substance in addition to the psychological one created when the brain associates the euphoric high and positive feeling to drug use. Most dangerous drugs can affect the body and mind in this way.

However, some drugs are more addictive — and thus, more dangerous — than others.

Each person is unique, and their bodies might respond to varying drugs and doses differently than other people’s bodies. However, certain substances have a high rate of addiction overall and regularly result in overdose deaths.

What Are the Worst Drugs?

Many of the most dangerous drugs in the world are also illegal, but some prescription medications can be extremely harmful when misused as well. These drugs range from stimulants that cause a spike in energy to depressants that bring the body into a tranquil state. Many drugs classified as opioids, both illegal ones and prescription medications, are included in this list.

The Centers for Disease Control and Prevention (CDC) releases the number of overdose deaths caused in the United States by each drug class.

As of July 2020, the top 3 worst drugs classes in terms of overdose deaths were:

  • Opioids have caused more than 61,000 deaths. Of these, more than 14,000 deaths were due to heroin.
  • Non-cocaine psychostimulants like methamphetamine, responsible for more than 20,000 deaths
  • Stimulants, including cocaine, were responsible for more than 18,000 deaths.

These are not the only dangerous drug classes, though. Many prescription and illicit drugs are easily accessible and dangerous. Everyone should be aware of them for their own safety and that of their loved ones.

Some of the Most Dangerous Drugs May Not Be What You Think

Some of the most dangerous drugs may be sitting in your medicine cabinet. A 2019 report analyzed the rates of death and risks for drugs and drug combinations to determine the 25 most dangerous drugs. Many well-known and frequently used drugs appear on the list, including:

Although the drugs may be safe when used correctly, they can be fatal when improperly combined or abused.

The Most Dangerous Drugs Were Not Opioids

Although opioid addiction is frequently in the headlines, the most dangerous drugs in the world are not always opioids or narcotics. The most dangerous drug was determined by a few factors, including mortality rates associated with that drug’s use or abuse. These deaths are frequently accidental.

Acetaminophen Was the Most Dangerous Drug

In a list of the top 10 most dangerous drugs, most people may not think of a drug as common as acetaminophen. However, acetaminophen, sold under brand names like Tylenol, was found to be the world’s most dangerous drug in the report. Acetaminophen is responsible for many dangerous drug interactions. Further, there is a high potential for liver damage from an acetaminophen overdose. Most people view the drug as innocuous, and that perception may contribute to its unintentional abuse.

Alcohol Was the Second Most Dangerous Drug

Among the top 10 most dangerous drugs comes another unlikely contender: alcohol. We don’t often perceive alcohol as a drug, but it is.

According to the National Institute on Alcohol Abuse and Alcoholism, in 2019, 25.8% of people in the United States reported binge drinking within the past month. The same report states that of the more than 85,000 cases of death as a result of liver disease in 2015, 43.1% of those cases were the result of alcohol abuse.

The risks of heavy and continued alcohol use are degenerative and can have long-term consequences on a person’s health. In a recent study of people who tried to stop their alcohol use, 47.1% of them qualified as heavy alcohol users.

Benzodiazepines Were the Third Most Dangerous Kind of Drug

Another common type of drug in the list of the top 10 most dangerous drugs is benzodiazepines. This includes popular brand names like ValiumRestorilKlonopinAtivan or Xanax.

This class includes some of the most dangerous prescription drugs because they are strong sedatives. When prescribed for sleep, anxiety or seizures, these drugs can offer relief, but they are also abused and sold illegally as downers. They can be lethal, especially when combined with opioids.

Hardest Drugs To Quit

Controlled substances are often very hard to quit. This is because people who become dependent on them will suffer from withdrawal symptoms. These uncomfortable effects can deter people from entering recovery, and many will continue to use a substance just to avoid the withdrawal symptoms. Further, controlled substances can cause dependence and lead to addiction.

Controlled substances include common street drugs like cocaineheroin and methamphetamine. They also include prescription medications such as CodeineOxyContinValium and Xanax.

The government tracks how many people use illicit controlled substances. According to the 2019 National Survey on Drug Use and Health, among U.S. Americans:

  • About 46.2% of people have used cannabis
  • Around 16.0% of people have used hallucinogens
  • More than 15% of people have used cocaine, including 3.4% of people who have used crack cocaine
  • More than 9% of people have used inhalants
  • Approximately 5.8% of people have used methamphetamine
  • About 2.1% of people have used heroin

Other Dangerous Drugs

Although some dangerous drugs are illicit street drugs, others are common prescription medications. The most dangerous drugs based on side effects, death rates and drug interactions include the following:

  • Anticoagulants (Warfarin): Blood thinners like warfarin can cause interactions with alcohol, leading to unpredictable levels of blood thinner in your body. If you drink while taking warfarin, you should tell your anticoagulation provider because they will need to monitor you carefully.
  • Antidepressants (SSRIs): One of the five most dangerous drugs that may be susceptible to abuse and addiction are SSRIs, or antidepressants. Certain antidepressants can be dangerous when taken with alcohol (such as Celexa and Effexor). SSRI antidepressants include Lexapro, Celexa, Zoloft, Effexor, Paxil and Prozac.
  • Clozapine: The drug clozapine (Clozaril, Versacloz) is FDA-approved to treat schizophrenia. Serious side effects can include abnormalities in your blood cells.
  • Cough medicine: The active ingredients in cough medicine may include guaifenesin, phenylephrine and dextromethorphan. Some cough medicines also contain alcohol. Cough medicine can be abused and may cause psychosis. Brands of cough medicine include Robitussin and Delsym.
  • Cocaine: Cocaine is a stimulant that can cause a stroke or heart attack. It is very addictive and susceptible to abuse.
  • Heroin and other Opioids: Heroin is made from poppies and influences the opioid receptors in the brain. It is highly addictive and susceptible to abuse.
  • MDMA: MDMA is an amphetamine analogue and may be referred to as ecstasy. This is an illegal stimulant and hallucinogenic drug that is often available in rave or club cultures around the world. MDMA can cause behavioral changes, memory loss and psychosis.
  • Methamphetamine: Meth or crystal meth is a stimulant that causes euphoria and is highly addictive. It is known as an upper and can be subject to overdose because it is unregulated and sold in multiple forms.
  • NSAIDs: Nonsteroidal Anti-Inflammatory Drugs, or NSAIDs, can be used to treat pain from arthritis or ulcers. Stomach bleeding and kidney problems are some of the possible negative side effects. Mixing NSAIDs like aspirin with alcohol can cause harmful side effects like stomach bleeding. NSAIDs include over-the-counter remedies like naproxen, ibuprofen and aspirin.
  • Tobacco: Tobacco is often consumed as nicotine in cigarettes, chew or e-cigarettes. Tobacco has no approved medical use and can lead to addiction as well as cancer, strokes and macular degeneration.

Find the Help You or a Loved One Needs

If you or someone you know struggles with an addiction to an illicit or prescription drug, help is available. Rehabilitation centers, such as The Recovery Village, have the staff and resources available to help people who are struggling with a substance use disorder. Many people die each year from illicit and prescription drug use, but many others have also successfully removed drug use from their lives. Call The Recovery Village to speak with a knowledgeable representative on which treatment plan is the best fit for you or your loved one.

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Editor – Melissa Carmona
Melissa Carmona puts years of writing and editing experience to work helping people understand substance abuse, addiction and mental health disorders. Read more
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Medically Reviewed By – Dr. Jessica Pyhtila, PharmD
Dr. Jessica Pyhtila is a Clinical Pharmacy Specialist based in Baltimore, Maryland with practice sites in inpatient palliative care and outpatient primary care at the Department of Veteran Affairs. Read more

Centers for Disease Control and Prevention. “Provisional Drug Overdose Death Counts.” Accessed February 21, 2021. “Clozapine.” September 5, 2020. Accessed February 21, 2021.

Substance Abuse and Mental Health Service Administration. “Results from the 2019 National Survey on[…]lth: Detailed Tables.” August 2020. Accessed February 21, 2021.

National Institute on Alcohol Abuse and Alcoholism. “Alcohol Facts and Statistics.” February 2021. Accessed February 21, 2021.

Bloom, Josh. “Is Tylenol ‘By Far The Most Dangerous Drug Ever Made?‘” American Council on Science and Health, September 11, 2017. Accessed February 21, 2021.

Sauter, Michael B. “The 25 Most Dangerous Drugs.” USA Today, July 31, 2019. Accessed February 21, 2021.

National Institute on Drug Abuse. “Benzodiazepines and Opioids.” February 3, 2021. Accessed February 21, 2021. “Warfarin.” July 18, 2020. Accessed February 21, 2021.

Martinak, Bridgette; Bolis, Ramy A.; Black, Jeffrey Ryne; et al. “Dextromethorphan in Cough Syrup: The Poor Man’s Psychosis.” Psychopharmacology Bulletin, September 15, 2017. Accessed February 21, 2021.

U.S. Department of Justice, Drug Enforcement Administration. “Drugs of Abuse.” 2020. Accessed February 21, 2021.

Medical Disclaimer

The Recovery Village aims to improve the quality of life for people struggling with substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare providers.