Heroin: The Best of the Worst

Is heroin the most addictive drug? Absolutely. More than crack cocaine, cigarettes, alcohol, or crystal meth, heroin takes the prize as the most addictive substance on earth1.

As to why it’s the most addictive has to do with a combination of factors including the speed in which it reaches the brain, its powerful effect on the brain’s dopamine system, and its brutal withdrawal symptoms.

Taking Advantage of Morphine Receptors

Because the human brain is able to make its own morphine, it naturally contains opiate receptors. This makes the brain a highly receptive to opiates like heroin. While our brains do produce morphine, it does so in small and steady amounts – nothing like crashing doses encountered in heroin. Heroin mimics natural brain chemicals that were naturally designed to control pain and enhance pleasure. As the drug passes through the blood-brain barrier it morphs into morphine. From there it is attracted to and attaches to the brain’s opiate receptors. According to experiments on lab animals, heroin can increase the brain’s dopamine levels by 200 percent2. (Just for comparison, sex also increases dopamine levels by 200 percent. This does not compare, however, to the levels of cocaine – 350 percent – or meth – 1200 percent!3)

Heroin also has a low 1:5 effective-to-lethal dose ratio. This means it only takes five times more of the drug to go from getting high to a deadly overdose. This low ratio is one reason why heroin is the number one killer of illegal drug users.

Heroin, like all opiates, also has a chemical structure similar to endorphins, a class of chemicals in the brain. When endorphins flood the synapses – the gaps between the neurons – they usually inhibit neurons from firing. This in turn produces pain relief and even euphoria. Our bodies produce endorphins when we exercise, go into labor, or experience a high level of stress.

What Makes Heroin More Dangerous than Other Drugs

First and foremost, what makes heroin the ultimate opiate – even more than morphine and synthetic opioids like Oxycontin, codeine, Percocet, Vicodin, and fentanyl – is the fast way it enters the blood in the brain. You can’t inject a drug directly into the brain but a small structural difference between heroin and an opiate like morphine (the two are nearly identical except for the substitution of two acetyl groups on the heroin molecule) is that heroin can get into the brain quicker. This is the reason why heroin is even more addictive than the opioid fentanyl, an opioid that is 40 to 50 times more potent than pure pharmaceutical grade heroin. Heroin not only gets into the brain quicker – it is the most fat soluble of all opiates – it provides a bigger “rush” and causes the addictive changes in the brain to occur much sooner and that much stronger.

Why Shoot Up?

Heroin is highly addictive no matter how it is used. It is a misconception that snorting or smoking heroin isn’t as addictive as using it intravenously. Users often prefer to shoot up because when heroin is taken orally, its effects are drastically reduced. This is due to the fact that heroin is converted to morphine when it is metabolized by your body. Intravenous use provides a way for the drug to cross the blood-brain barrier very quickly. The user’s blood level of the drug determines the high – the faster the blood level rises, the greater the high. It’s this rapid rate that effectively creates the euphoria. Intravenous use allows the greatest intensity and most rapid onset of effects. Users can feel peak effects after seven to eight seconds. A euphoric high can be produced within five to eight minutes of intramuscular injection. When the drug is sniffed or smoked the effects can be felt within 10 to 15 minutes. The euphoria is followed by a period of sedation that can last a few hours.

Tolerance and Side Effects

With repeated use, users develop a physical tolerance in which more heroin is needed to achieve the same effect. Abusers will need higher and higher doses. When physical dependence develops, the body will get used to the drug and need it to feel normal. Without the drug the user will experience serious withdrawal symptoms.

Another side effect is severe itching.

After entering the brain, heroin converts to morphine and binds to the opioid receptors in the brain and body. This causes a surge of euphoria and a warming flush to the skin. In the process heroin can cause histamines – something the body produces during allergic reactions. When released, histamines irritate the skin making it crawl and itch. In response the user will want to scratch for relief: the purer the heroin, the greater the itch.

Other short-term side effects include dry mouth and foggy brain. Long-term effects include inflammation of the gums and bad teeth, serious constipation, cold sweats, respiratory illness, weakening of the immune system, memory loss, depression, and pustules on the face.

Then there is the withdrawal: While the symptoms aren’t life-threatening, they are extremely unpleasant. They can include nausea, vomiting, insomnia, diarrhea, and sweating.

What’s Worse than Heroin?

Heroin, like all opiates, suppresses breathing. When given enough of the drug, the body forgets to breathe. This can cause death. When heroin is combined with drugs that also suppress breathing, such as alcohol or benzodiazepines, it can also result in death.

One of the great unknown risks of heroin is the potency of the drug being taken. One of the negative consequences of illegal heroin is that it is distributed, sold, and used without any protections or regulation, especially when it comes to the quality of ingredients or drug purity. When a user measures out a dose of heroin, they have no idea what substances were used to cut the drug. They can be from the benign – powdered milk and starch – to the deadly – quinine, strychnine, or other drugs such as fentanyl. Fentanyl cut heroin has been in the news recently and it hasn’t been pretty4.

If you or a loved one have an addiction to alcohol, contact BLVD Treatment Centers. At BLVD Treatment Centers we custom tailor our recovery programs within the safe and nurturing confines of our rehab treatment centers. Located throughout California, in Los Angeles, Orange County, San Diego and in Portland, OR, our mission is to assess the severity of your addiction to help you achieve true recovery within 30 days. Call us now at 1-866.582.9844.

  1. Development of a Rational Scale to Assess the Harm of Drugs of Potential Misuse, David Nutt, et al., March 2007
  2. Wiley Online Library. Elevations of Nucleus Accumbens Dopamine and DOPAC Levels During Intravenous Heroin Self-administration Retrieved April 6, 2016
  3. National Institute on Drug Abuse. Addiction Science Publications. Retrieved April 6
  4. Los Angeles Times. Powerful Opiate Fentanyl Suspected in 10th Northern California Overdose Death. Retrieved April 6, 2016.

Is Heroin the Most Addictive Drug?