How Much Heroin Can Lead to a Dangerous Overdose?

Medically Reviewed

Some often wonder how we reached this point in our lives and how we’re witnessing this pure devastation of the opioid crisis. To better put this into perspective, we are losing people at a rate more alarming than that during the Vietnam War. More Americans have died as a result of opioid overdoses than souls lost in the entire Vietnam War. This statistic illustrates 140 Americans dying daily, and when it is broken down even more in-depth, it translates to one person every eight minutes losing their lives to opioids like heroin. Where did this all start?

Heroin addiction and opioid abuse have been prevalent in our society for centuries, but it wasn’t until the late 1990s that this current epidemic was born. Pharmaceutical companies sent their representatives to doctors out in the field and reassured the entire medical community that patients would not become addicted as a result of using opioids. How did doctors respond? They listened and began prescribing opioids at historical rates. This led to widespread misuse of both prescription and non-prescription opioids. It soon became clear that these were highly addictive.

In 2017, the U.S. Department of Health and Human Services declared a public health emergency to address the national opioid crisis. In 2015, 52,404 Americans died from drug overdoses, and in a sharp rise in 2016, that number rose to an estimated 64,000 people. After declaring the emergency, the Department of Health and Human Services worked alongside President Donald Trump to create a new Five-Point Opioid Strategy.

The following priorities were for improved access to prevention, treatment, and recovery support services, target the availability and distribution of overdose-reversing drugs, strengthen public health data reporting and collection, support cutting-edge research on addiction and pain, and advance the practice of pain management.

The overprescribing of opioids led to users turning to illegal methods to obtain their drugs. With access to prescription drugs becoming more difficult and driving up the prices, this has forced people to purchase illicit street drugs like heroin or fentanyl. It has caused the problem to become much worse. This begs the question of how much heroin can lead to a dangerous overdose? Various factors can influence heroin overdose, which we’ll explain below.

How Much Heroin Can Lead to an Overdose?

Heroin is a highly addictive, illegal opioid. Those who use heroin can experience intense side effects in the short-term and long-term. In 2015, 81,236 emergency department visits occurred for unintentional, heroin-related poisonings in the United States, which is a rate of 26 per 100,000 people. Past misuse of prescription opioids is the most substantial risk factor for starting heroin use, which is especially true among those who became dependent upon or abused prescription opioids in the past year. From 2000 to 2013, three out of four people report having misused prescription opioids before using heroin.

What makes the question of how much heroin can lead to an overdose challenging to answer is that today, a bag of heroin may contain only some heroin. With the emergence of fentanyl-laced heroin, it has made it nearly impossible to answer that question. This trend has become evident in the Northeast where heroin is cut with fentanyl and even given brand names and packages to indicate that it is fentanyl. Fentanyl is one of the most potent opioids on this planet and is estimated to be anywhere from 50 times to 100 times stronger than a standard dose of heroin. The process has become routine for dealers who can increase their profits from the cheap synthetic opioid.

To answer the question about how much heroin can lead to a dangerous overdose? There is no answer to theat question. There are so many different factors including, are the drugs tainted? How long has someone been using? Do they have a high tolerance? Are they healthy? How much do they weigh? As you see, several factors influence the outcome of a heroin overdose, and the safest method to practice is to avoid using heroin or seek treatment immediately.

There are ways to determine if someone has overdosed on heroin. The person will exhibit these symptoms:

  • Pinned pupils (contracted, appear small)
  • Muscles are slack and droopy
  • Nodding out
  • Scratching their skin
  • Slurred speech
  • Loss of consciousness
  • Unresponsive to outside stimulus
  • Awake, but unable to talk
  • Slow and shallow breathing
  • Choking sounds
  • Vomiting
  • Limp body
  • Face is pale or clammy

Since heroin is a depressant, it can stop a person’s breathing, which can lead to irreversible brain damage, coma, and death. If you suspect someone has overdosed on heroin, you must immediately call 911. The sooner help arrives, the sooner treatment can begin and the person can avoid long-term damage or death.

Effects of Heroin

Heroin is a powerful drug, and it can affect the body and the brain in several ways. High doses of the drug can be dangerous and even life-threatening, but it can also cause several consequences after long-term use. Heroin can cause a deadly overdose when it’s taken in high doses or mixed with other drugs, but it can also cause a severe substance use disorder after long-term use. Addiction increases your risk of overdose and other serious consequences.


Once heroin enters the brain, it converts to morphine and binds rapidly to opioid receptors. Someone who uses heroin reports feeling a surge of pleasurable sensation known as a rush. The intensity is dependent on the amount that is taken and the purity of the drug. The rush is accompanied with warm flushing of the skin, dry mouth, and a heavy feeling in the extremities.

The user can also be drowsy for several hours and have clouded mental functions. The breathing in someone who consumed a large amount will also be strongly affected, and in some cases, be life-threatening.

Someone using heroin in the early stages may not show the outward signs of a substance use disorder, but the deeper they fall into the grips of heroin addiction the symptoms will become much more apparent.


With the continued use of heroin, there are physical and physiological changes in the brain. It creates a long-term imbalance in neuronal and hormonal systems that can take years to reverse. Other studies have shown deterioration of the brain’s white matter due to heroin use which can affect decision-making abilities, the ability for normal behavior, and responses to stressful situations. Heroin also can produce high degrees of tolerance and physical dependence.

Withdrawal can occur in as little as a few hours after the last time the drug was ingested. Significant withdrawal symptoms peak around 24-48 hours after the last dose and subside after a week. Repeated heroin use can result in a heroin use disorder—a chronic relapsing disease that goes beyond physical dependence and is characterized by uncontrollable drug-seeking behavior.

No matter how heroin is consumed, it is highly addictive. When someone reaches the point of a heroin use disorder, obtaining and using the drug becomes their only purpose in life. Due to the changes in brain chemistry, long-term use will have adverse effects, and the best option someone has is to inquire and seek treatment to begin treating their addiction. Living in an active heroin addiction can rob someone of their life and harm their relationships with everyone around them.

Why is Illicit Heroin Inherently Dangerous?

Heroin was once used medicinally in the United States, but it’s now a Schedule I drug. That means that it’s federally recognized to have a high potential for abuse with no currently accepted medical uses. When you get heroin, it’s coming from an illicit source, which means that it’s unregulated and unpredictable. Of course, that means that when you believe it, heroin might be a mixture of other inert and active substances. Today, one of the biggest dangers of using illicit heroin is the threat that it’s mixed with fentanyl or one of its analogs. However, heroin may be unpredictable, even without the presence of other powerful drugs. 

Heroin is created and trafficked through transnational criminal organizations, especially the Mexican cartels. As they enter the country, they pass through many hands on the supply chain. Each drug dealer has the potential to add new ingredients to the mix. For the most part, inert substances are added to heroin and other drugs to increase profits. A cheap and easy-to-find adulterant can bulk up the product. The dealer is left with an increased supply and they can then sell the adulterated heroin. 

Heroin users may have no idea how pure or adulterated the heroin they are using actually is. The result is a drug with unpredictable purity and strength. This becomes dangerous when neighborhoods of heroin users get used to weak, diluted heroin. They may compensate to find an effective dose, thinking that’s a normal dose of heroin. Then, when they encounter purer heroin, their normal dose is actually too high. This can cause a dangerous overdose. 

Because illicit heroin is so unpredictable, each day in active heroin addiction is life-threatening. The next dose could be deadly.  

What are the Effects of Heroin Withdrawal?

Heroin can be dangerous during an overdose, but how dangerous is it during withdrawal. Withdrawal is caused by your body’s adaptation to the drug and the sudden chemical imbalance in your brain that’s caused when you quit using heroin. Heroin is notorious for causing extremely uncomfortable flu-like symptoms, including nausea, vomiting, chills, fever, sweating, diarrhea, and body aches. Heroin isn’t known to be deadly in the same way that other substances like alcohol can be during withdrawal. 

However, it can cause some medical complications if it causes dehydration. Since withdrawal can cause vomiting, sweating, and diarrhea, it can cause you to lose water quickly. However, you can usually overcome this by drinking plenty of water. If you can’t keep water down, you may need to speak to a doctor. 

Withdrawal can also cause powerful cravings to use heroin again. If you get through withdrawal successfully, your heroin tolerance will start to go down. If cravings cause a relapse, it can lead to an overdose if you take the dose you were used to before you quit.

How is Heroin Addiction Treated?

Heroin addiction, as we’ve mentioned above, can have irreversible consequences, and the only way to avoid a heroin overdose is to stop using the drug and get treatment immediately. For some, getting trapped in the perils of addiction can feel like they’re stuck in quicksand, and the harder they fight, the deeper they sink. 

However, heroin addiction is treatable through addiction treatment. Medical detox, inpatient treatment, and outpatient treatment are used to treat substance use disorders. Since each day addicted to heroin can be dangerous, it’s important to seek treatment as soon as possible. 

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