The Most Addictive Illegal Drugs in the World

Heroin and cocaine are incredibly dangerous drugs. Using them can result in overdose and death. They’re also the two most addictive drugs in the world.
When it comes to the fight against drug use and abuse, knowledge is power. Here is what you need to know about the world’s most dangerous illegal drugs — and what you can do if someone you know is in danger of becoming addicted.


Ask anyone what the most dangerous drug in the world is and chances are you will hear “heroin” in response. Made from the opium poppy, heroin is a powerfully addictive central nervous system depressant that becomes morphine inside the human body.

Although many users prefer injecting it for the fastest high, the powerful substances sold today are strong enough for snorting and smoking. This is causing a huge addiction problem in younger users, who may be afraid to inject but do not fear snorting or smoking.

Heroin causes a number of notable physical and emotional symptoms. Among these symptoms are tolerance and physical dependence, which serve to intensify addiction.

By all accounts, a heroin habit is one that is extremely difficult to quit. Many independent estimates report that heroin-addicted people relapse into abuse following sobriety more than 90 percent of the time. Heroin abuse also frequently leads to health problems such as HIV, hepatitis, poisoning, and kidney problems. Overdose can be fatal.


Cocaine comes from the leaves of the coca plant. It has a powerful, nearly instant affect on the learning and reward centers in the brain, which is why the drug is so addictive.

It is common for people who try to quit using cocaine alone to sink into a depression that lasts for months, accompanied by cravings to use cocaine. This is why people who develop an addiction to cocaine sometimes relapse into abuse after a period of sobriety. Hospital emergency departments report cocaine abuse more frequently than any other illicit drug, according to

Cocaine is a central nervous system stimulant that causes intense psychological addiction as well as numerous physical health problems. People who abuse cocaine typically snort, smoke, or inject it.

Unlike heroin, which causes users to fall asleep, cocaine causes alertness, overconfidence, restlessness, and paranoia. With prolonged abuse, a user might alternate between depression and agitation. Itchiness, hallucinations, delusional behavior, and problems with heart rate and blood pressure are also common. Overdosing can be fatal and often results from heart attack.

Getting Help

Did you know that enrolling in long-term treatment customized to the needs of the individual improves addiction treatment outcomes? Although it is difficult to measure treatment outcomes, the National Institute on Drug Abuse reports that those who get help early and make ongoing counseling a regular part of life are more likely to stay sober.

If someone you know is abusing heroin or cocaine, early treatment is essential. Treatment can also reduce withdrawal symptoms and manage the symptoms associated with many mental health disorders.

Contact 12 Keys to speak to a counselor today.

The Addiction Blog