What Are the Most Dangerous and Addictive Drugs? And What Makes Them So Bad?

Alcohol and other drugs have a lot of power to create dangers, harms, and risks to the people using them. Not all drugs are created equal, however. 

Some drugs may have a low risk for abuse, addiction, and substance use disorders. Others, meanwhile, can quickly create addiction and wreck many lives along the way. Finding the worst drug will not be easy. But working to understand the unique risks of drugs and alcohol is a great way to protect yourself and the people you care about.

Read on to learn about the worst drugs and the harms they create.

What makes a drug dangerous?

When looking at the worst drugs, you have to consider several factors. When considering the most problematic drugs, ask yourself the following: 

• Can the drug cause an overdose? The ability of the drug to kill you definitely makes it bad.

• Can the drug cause quick and intense addiction? Addiction tends to consume your mental health and makes each day all about getting and using the drug.

• Can the drug kill you in the long-term? Even if the drug cannot trigger an immediate overdose death, the combined effects of use over the years can create many physical health risks.

• Can the drug hurt your loved ones and complete strangers? The worst drugs not only affect you, but they impact the lives of your loved ones as well as strangers.

• Is the drug available? Some of the world’s most dangerous drugs are available in such a short supply that they cannot harm many people, so the most dangerous drugs must be accessible by a lot of people.

Any substance with the power to create all of these effects is clearly harmful. You should always look to avoid drugs that produce these negative outcomes.

What drugs are the most dangerous or addictive?

By reviewing the harmful factors, several drugs emerge as candidates for the worst drugs. The worst drugs are:

• Alcohol

• Fentanyl

• Methamphetamine

Settling on the “worst” drug is impossible because they are all uniquely dangerous. But these are some of the worst offenders based on the factors above.

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What makes alcohol dangerous?

Alcohol meets all of the items for being a problem. It is widely available. It is risky in the short-term and dangerous in the long-term. And it can create addiction and alcohol use disorders. 

The dangers linked to alcohol include: 

• Alcohol overdose death from alcohol poisoning

• Increased risk of accidents like drowning and car wrecks

• Liver disease

• Heart disease

• Various cancers

• Pregnancy complications and fetal alcohol syndrome

Americans’ relationship with alcohol is complicated. On the one hand, millions of people responsibly use the substance each day. On the other hand, almost 15 million people have an alcohol use disorder.

Additional alcohol statistics point to the danger:

• Each year, 95,000 people in the U.S. die from alcohol-related issues.

• About 210,000 trips to the ER each year are due to alcohol.

• Every 52 minutes, someone dies from a drunk driving crash.

• More than 10,000 people die each year from drunk-driving accidents.

For people under 21, alcohol is highly connected to car crashes, injuries, and suicides. While drinking, people are more likely to harm or even kill others.

What makes fentanyl dangerous?

While alcohol is legal and widely available to people, fentanyl is a highly controlled prescription medication as well as an illegal street drug. Fentanyl is an extremely powerful, synthetic opioid drug. It can be snorted or injected alone or in combination with other drugs.

Fentanyl is 50 times stronger than heroin and 100 times stronger than morphine. Because this drug is so strong, you could overdose and die any time you use it.

Fentanyl is cheap and powerful, so drug dealers will add it to batches of heroin to save money and deliver a stronger product. Measuring amounts of fentanyl is hard, and adding just a little bit more could lead to deadly results.

Drug overdoses in the U.S. continue to climb at rapid rates.There were about 100,000 drug overdoses in 2021 alone, with fentanyl and other opioids leading the way. Of all the overdose deaths, more than 75% were caused by opioids and more than were 64,000 caused by synthetic opioids like fentanyl.

What makes methamphetamine (crystal meth) dangerous?

After opioids, stimulants like methamphetamine are connected to the highest numbers of overdose deaths. Almost 1 out of every 4 overdose deaths involve these stimulants. Like fentanyl, amphetamines have a medical benefit, but most of the harms come from people abusing the drug. People can even manufacture crude versions of meth (crystal meth) in their homes.

Meth is very powerful and addictive, like cocaine, but it produces more dangerous effects. Smoking crack cocaine produces a brief high before leaving the body in 1 hour. Smoking meth, though, creates a longer, more addictive high and stays in the body for 12 hours.

Meth can damage brain cells that can cause problems with emotions and memory. It can also produce:

• Confusion

• Anxiety

• Extreme paranoia

• Hallucinations, where you see, hear, or feel things that are not really there

In some situations, these effects can result in a person becoming violent and aggressive with others. This aggression could be directed toward loved ones, friends, or themselves.

How dangerous are cigarettes?

Just as you may overlook the dangers of alcohol, you could overlook the danger of cigarettes. From a standpoint of availability, addiction, and deadliness, cigarettes are worse than the others.

Cigarettes and other tobacco and nicotine products are offered at just about every gas station and corner store in the country. They are also highly addictive. About 1 in 11 people who use cannabis (marijuana) regularly have a substance use disorder. But about 50% of people who smoke cigarettes have one.

The worst part of cigarettes are the health effects. Each year, about 480,000 people die from smoking-related issues, including lung cancer, heart disease, and numerous breathing issues. That equals around 1,300 deaths each day.

What substances aren’t the most dangerous, but still have risks?

It’s important to note that no drugs are safe for all people. All substances carry the possibility of harmful effects. So, just because one drug may seem safe for some people does not mean it is safe for you.

Hallucinogen drugs like psilocybin and ayahuasca are not usually associated with high levels of abuse and addiction. But they can still disrupt your life in the long-term and trigger some scary physical and mental health effects in the short-term. Overall, though, these drugs rarely enter the conversation regarding the worst drugs.

The same is true with cannabis. Although cannabis’s risks and benefits continue to be debated, few people would consider it one of the most dangerous, damaging, or harmful drugs.

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Written by:

Eric Patterson, LPC

Eric Patterson, LPC, has been a professional counselor in school and outpatient settings — working with clients of all ages to achieve happiness, good mental health, and better lives — for over 15 years. Since 2010, he has provided clinical supervision to other therapists hoping to refine their skills and become licensed professionals.

Reviewed by:

Emily Guarnotta, PsyD

Emily Guarnotta, PsyD, is a licensed clinical psychologist and certified perinatal mental health professional with over 10 years of clinical experience.

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