A List of Most Addictive Substances

For many years, researchers have classified and ranked the most addictive substances in the world by the factors influencing the addiction, the degree of tolerance, and the intensity of the withdrawal symptoms once the drug addict decides to stop using. With these factors, researchers were able to rank specific drugs according to their addictiveness. So what are the most addictive substances out there? Here are the list of drugs that you should look out for:


Heroin is perhaps one of the most “popular” drugs used and abused by many people today. It is an opioid derived from morphine. Among others, this drug has the highest score in terms of dependence. Heroin addicts are after the euphoric feeling that this drug gives. This is taken by snorting, smoking and injecting the drug into their body. Tolerance buildup does not take long to develop either, and many drug addicts will increase the dose of heroin consistently over a short period of time just to achieve the same effect. 

Withdrawal symptoms for heroin can be very unpleasant. This usually involves severe bone pain, muscle aches, vomiting, diarrhea, restlessness, uncontrollable leg movements and even cold flashes. Long term side effects of heroin can result in the depletion or loss of white matter in the user’s brain. Because of this, a person’s ability to control their behavior or make sound decisions are affected. This is also the reason why heroin is one of the most addictive substances today. In fact, heroin has exacerbated the U.S. opioid epidemic and according to NIDA, about 15,500 Americans died from heroin overdose alone in 2016. The drug is currently very much illegal in the United States. 


Another addictive drug that many people are apt to abuse is cocaine. This often comes in white crystal powder form that can be injected, snorted, rubbed into gums or smoked. In some cases, people mix cocaine and heroin together and call it speedball, which is a very potent form of drug. Drug dealers also mix this with flour, talc powder and even cornstarch to increase their profits. A lot of times, dealers will cut cocaine with fentanyl which heavily increases the risk of overdose. 

Cocaine users typically experience an intense rush of energy and euphoric feeling after taking it. The most common effects of this drug is building up dopamine in the brain that causes one to feel good. Once this is done repeatedly, a person’s tolerance to the drug increases over time and causes them to need to use more to obtain the desired effects. Common withdrawal symptoms of cocaine abuse usually involve depression, insomnia, nightmares, slowed thinking, poor concentration, and fatigue. Snorting cocaine can cause side effects such as runny nose, loss of sense of smell, nose bleeding, and even problems with swallowing. On the other hand, ingestion of cocaine can also lead to severe bowel decay and certain cancers involving the bowels. 

Recreational use of cocaine is illegal in the U.S. and about 11,000 Americans were reported to die from cocaine overdose back in 2016. 

Tobacco or cigarettes/nicotine

The third most addictive substance in the world is nicotine, found in tobacco products such as cigarettes and chewing tobacco. The nicotine found in tobacco leaves is the reason why many people are addicted to it. It can be smoked in many apparatuses such as pipes, hookah products, cigars, bidis, kreteks and even e-cigarettes or vape. Withdrawing from nicotine usually results in intense tobacco cravings. Smokers will exhibit irritability, insomnia, loss of concentration, and an increase in their appetite. This is also one of the reasons why many who stopped or quit smoking gain weight quickly. 

According to the U.S. Department of Health and Human Services, about 20% of adults and teenagers in the U.S. smoke. About 34 million Americans living in West Virginia, Kentucky and Louisiana are smokers, while the smallest number of people smoking are in California and Utah. Smoking has been proven to be dangerous for your health that since 1964, about 20 million people in the U.S. have died due to it. It has also been estimated that by 2030, about 8 million people will die due to smoking.


Barbiturates are depressant drugs also known by their street name as gorillas, blue bullets, nembies, pink ladies and barbs. These drugs were initially created to treat patients with anxiety and to promote sleep. However, they have been proven to interfere with the chemicals in the brain which eventually shuts down other regions in it. 

If taken in low dosages, barbiturates can cause euphoria to the user. Higher doses on the other hand can suppress breathing and can stop the function of the lungs if taken in larger doses. Withdrawal symptoms from barbiturates include feelings of anxiety, dizziness, seizures, insomnia, and psychosis. If these are not treated immediately, barbiturates can cause circulatory failure, hypothermia, and eventually death. 


Getting your hands on alcohol is extremely easy in the United States and in other countries. Because of this, alcohol is one of the most widely abused substances, not just in the U.S., but all over the world as well. In fact, experts stated that about 22% of people who have drank alcohol will develop dependence to it at some point in their lives. Alcohol mainly affects the brain by increasing up to 40-360% of the dopamine levels. The more alcohol a person takes in, the more dopamine is released. In 2002, the World Health Organization (WHO) has estimated that about 2 billion people have used alcohol, and more than 3 million people in 2012 died due to alcohol poisoning and other other deaths caused by drinking. 

Excessive alcohol drinking can lead to a long list of health issues which includes high blood pressure, stroke, alcohol poisoning, depression, memory loss and anxiety. Withdrawal symptoms for alcohol can also result in delirium tremens, which is one of the main causes of alcohol-related deaths in the country. Not only that, but alcohol addiction can also result in seizures, tremors, and hallucinations. 


Benzodiazepines are commonly prescribed medications given to reduce anxiety, promote relaxation, sleep and reduce seizures. However, because of their addictive properties, many people have abused them. Among the most common benzodiazepines are Valium, Xanax, and Restoril, which are helpful in promoting sleep and reducing anxiety. Withdrawal from these drugs can cause panic attacks, dry heaving, nausea, headaches, sleep disturbances, muscle pain, and stiffness. These can be very unpleasant to the user, which is why supervised detox is recommended. 


Amphetamines are mainly used to treat people with Attention Deficit Hyperactivity Disorder (ADHD) and narcolepsy. These drugs are also known as stimulant drugs, which helps people stay alert. One of the most common forms of amphetamine is the illegal drug Methamphetamine, that when taken causes the user to feel energized, happy, confident and have increased sex drive. In addition to that, users will also experience teeth grinding, increased heart rates, and dry mouth. 

Meth can be taken with caffeine, sugar and other binding agents to make swallowing easy. It can also be smoked, injected or snorted however, once the user decides to stop using this drug, withdrawal symptoms can be very uncomfortable. Users will exhibit restlessness, depression, confusion, paranoia, feel aches and pains, irritability, nightmares, and exhaustion. 


Derived from the cannabis indica plants, cannabis is commonly known as Marijuana and has proven to be one of the most commonly used substances among many people. Medical marijuana has more recently become popularized as it can help in relieving chronic pain, multiple sclerosis, and even nerve pain. It has also helped lessen the tremors in people with Parkinson’s disease as well as treating glaucoma. This may also be the reason why it has been legalized in many states in the U.S.. 

While it is not entirely proven to contain addictive properties, many users have developed dependence on this substance. Withdrawal symptoms from marijuana includes a decrease in appetite, difficulty in sleeping, mood swings, physical discomfort, restlessness, and cravings. 

These are eight of the most addictive substances in the world. If you know anyone who is addicted to the substances mentioned in this list, it is best to seek medical treatment right away. Prevention is the best way to decrease instances of addiction, so spreading awareness and knowledge about these substances and why they are harmful is good for you and those around you.