Illicit use of drugs doesn’t come without risks–whether big or small. Some drugs, however, pose more life-threatening consequences than others. What are the most dangerous drugs that are accessed by their users? Here is a comprehensive list.

When drug use turns into an addiction, it becomes a concern. The illicit use of drugs in high dosages causes mental, physical, and social consequences. Although some would contest that some drugs are medically safe for recreational use, there are still varieties that could potentially harm their users.

Why are Some Drugs More Dangerous than Others?

Fast-Acting Capabilities

Most dangerous drugs are fast-acting, quickly entering the bloodstream and affecting the brain’s neurotransmitters. This means that the person taking them will frequently experience feelings of relief, euphoria, or any pleasurable experience they can get from a single hit. The fast-acting capabilities of these drugs make the user prone to gradually taking higher amounts, which can result in an overdose.

Withdrawal Symptom Severity

Others get addicted to the most dangerous drugs because they avoid the withdrawal symptoms that accompany them when quitting. Some drugs have severe withdrawal symptoms that you might need medically-assisted drug detoxification. Another purpose of drug detoxification is to avoid the fatal consequences of severe drug withdrawal. A severe withdrawal can cause the body to “crash” because it cannot function without the drugs in its system.

Brain Affectations

Aside from the speed of drug effects, another reason why some drugs are more dangerous than others is the severity of change in the brain. There are specific substances that mimic the brain’s natural neurotransmitters, but there are others that elicit larger amounts of dopamine. The larger amounts of dopamine can cause a higher risk of addiction and overdose.

As we understand why some substances bring more harm than others, here is a concise list of the most dangerous drugs available.

The Most Dangerous Drugs in Existence


Buprenorphine is a prescribed drug used to treat opioid addiction. Consequently, it can also have addicting effects as it could mimic the same pleasurable sensations that opioid addiction can bring. It is known as an opioid agonist, which is responsible for lowering the dependency on opioid medication. Though the risk for addiction is low, buprenorphine can be potentially fatal when mixed with alcohol or other substances.

When used for recreational purposes, the risk of buprenorphine addiction is higher. Commonly known as “subbies,” some say this drug is simply a substitute for opioids. When taking buprenorphine, it is important to follow the doctor’s orders about the dosage to avoid the possible risk of addiction.


Though not a common addiction compared to the other most dangerous drugs, solvents can cause serious side effects in the brain and the body. Solvents, otherwise known as inhalants, are the varieties of industrial or household substances that produce volatile gases which cause intoxication.

These intoxicating gases can mimic the effects of other substances, which are a temporary feeling of euphoria, calmness of mind, or a heightened state of energy. The effects can vary depending on the type of inhalant used. These solvents can be risky as they can cause hypoxia or lack of oxygen in the brain. Hypoxia can lead to brain damage, cardiac arrest, or even death. Other risks of solvents include pneumonia, respiratory aspiration, or other lung problems.


Ecstasy is the common name for MDMA or 3,4 methylenedioxy-methamphetamine. It is known as a stimulant that brings hallucinogenic effects. Another known variety of MDMA is Molly. Molly and Ecstasy have MDMA ingredients, but the main difference is that Ecstasy is in a pill form while Molly is usually in powder or crystal form.

Ecstasy and molly are considered among the most dangerous drugs because they have a high risk of overdose among their users. Since it is commonly used at parties, users do not usually take the time to take precautions about their dosage while accompanying it with alcohol. High doses of MDMA can cause seizures, heat stroke, foaming at the mouth, coma, and even death.


Amphetamines are commonly prescribed drugs used as stimulants. It helps excite the brain’s central nervous system, allowing users to experience higher levels of energy, focus, confidence, and in many instances, a feeling of euphoria.

Amphetamines have been used for a variety of purposes, starting for their first debut during the 1800s for nasal congestion. Later on, the drug was used to treat hangovers, promote weight loss, improve concentration for ADHD patients, and to aid in narcolepsy. The potentially fatal risks of amphetamine overdose includes stroke, heart failure, or heart attack. Since the drug is considered a stimulant, people may lose their perception of danger, leading them to do risky activities. Amphetamine users are prone to the dangers of drunk driving, operating equipments without safety precautions, or engaging in violent acts.


Benzodiazepine, with the street name “benzos”, is popularly known for its sedative effects. They are considered as receptor agonists, and are widely used to treat symptoms of insomnia and anxiety. A lot of patients who suffer from insomnia and anxiety report prolonged relaxation, but others develop a risk of dependence on these drugs. The most common brands of benzodiazepine incluse Xanax, Klonopin and Ativan. These drugs were the most prescribed psychotropics over the last decade.

Benzodiazepine can be one of the most dangerous drugs because they have sedative properties, which means they can slow down respiration and heart rate. When taken in high doses, the person may suffer from organ failure, hypoxia, and death. Others may take the drug in mistakenly high doses, go to sleep, and end up not waking up at all. Those who take benzodiazepine for prolonged periods are also more prone to car accidents, cognitive impairments, and hip fracture.


Methadone is a substance that is given through prescriptions or can be used illicitly. This substance has a “street version”, often used as a way to relieve pain. Methadone is commonly given to patients who are suffering from chronic pain such as cancer, bone fractures, post-operation, or fibromyalgia.

Some doctors would also prescribe methadone for patients who are recovering from heroin or prescription painkillers. When taken in large doses, Methadone can cause irregular heartbeat, respiratory dysfunction, tremors, seizures, allergy reactions, and death from overdose.


Barbiturates are wide variety of drugs that are sedative in nature. They are used to treat symptoms of insomnia, anxiety, and epilepsy. However, prolonged use of the drug has proven to be dangerous for some as barbiturates have highly addictive qualities.

These substances are considered most dangerous drugs because they have a high potential for abuse and drug dependence. When taken in large doses, barbiturates may cause psychosis, aggression, emotional instability, depression, and thoughts of suicide. During an overdose, there is a high chance of stroke, coma, organ failure, or death due to respiratory dysfunction.


Cocaine is a highly-addictive stimulant type of drug that comes from the coca plant. This substance has other common street names such as Coke, Blow, Snow, or Crack. Cocaine sends very high levels of dopamine in the brain, creating a low barrier of drug dependency. The drug brings a high level of alertness, euphoria, and increased confidence.

However, since the drug is highly addictive, some people develop a dosage tolerance, making them reach lethal amounts. Some of the dangers of cocaine include heart failure, stroke, coma, seizures and death. There is also a high chance of acquiring HIV if Cocaine is taken with shared injection needles.


Methamphetamine with the street name “meth” is also a powerful and highly addictive stimulant. This drug is known to increase alertness, improve concentration, and allows users to achieve a high sense of euphoria. The pleasurable feelings associated with taking Methamphetamines also comes from its ability to release large amounts of dopamine in the brain.

Similar to Cocaine, this drug also allows a low barrier for addiction as it is fast-acting and presents strong effects. However, high doses of Methamphetamine can be fatal. Some risks of meth overdose include convulsions, coma, stroke, heart failure, hyperthermia (increased body temperature), and death.


Heroin is a type of opioid drug which is the body turns into morphine. Morphine is a substance derived from the pod of opium poppy plants coming from Mexico, Asia, and Colombia. Heroin usually comes in powder form, either white or brown sold in individual packages. There’s also a variety called black tar Heroin which contains the same substance in a dark sticky liquid form. Other names of Heroin include Horse, Hell, Big H, Smack, and Dust.

Out of all the substances in the list, Heroin tops the most dangerous drugs because this drug can enter the brain quickly than most. It binds to the opioid receptors, causing several mental and physical effects. The quick-acting drug presents effects that users describe as a feeling of “rush”, an intense amount of pleasure or euphoria.

As a result, Heroin is extremely addictive and people are prone to having a condition called Heroin Use Disorder, which is described by chronic cycles of relapse with a potential risk of low tolerance and overdose. Potentially fatal risks include poor blood circulation, respiratory failure, unresponsiveness, and coma. When left untreated, prolonged Heroin use can cause death.

Understand the drugs, understand the risks

A part of fighting addiction that you learn in inpatient rehab is understanding the effects of drugs on the body and its potentially harmful risks. If you or your loved one is suffering from drug abuse, reading through these facts can prompt you to get help. It is never too late to recover from drug addiction.


Medical disclaimer:

Sunshine Behavioral Health strives to help people who are facing substance abuse, addiction, mental health disorders, or a combination of these conditions. It does this by providing compassionate care and evidence-based content that addresses health, treatment, and recovery.

Licensed medical professionals review material we publish on our site. The material is not a substitute for qualified medical diagnoses, treatment, or advice. It should not be used to replace the suggestions of your personal physician or other health care professionals.

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