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Heroin was first introduced in 1898 as an upgrade to morphine. At the time, morphine was the latest and greatest cough-suppressing medicine for people with asthma.

While heroin is a much stronger opioid than its predecessor, it can also cause a number of serious side effects. These include a high risk of physical dependence, which may progress to addiction, or opioid use disorder, in some people. That’s why today’s medical professionals no longer use heroin.

In fact, unlike many other opioids, heroin isn’t legal in any context.

Legality aside, more than 900,000 people used heroin in 2019 in the United States. If you or somebody you know is part of that group, this article is for you.

Here’s a basic rundown of what to know about using heroin, including how long it stays in your system, side effects, and signs of an overdose.

Healthline does not endorse the use of any illegal substances, and we recognize abstaining from them is always the safest approach. However, we believe in providing accessible and accurate information to reduce the harm that can occur when using.

Heroin comes in three forms:

  • White powder: This is the purest form of heroin available. It appears similar to flour or sugar.
  • Brown powder: Brown heroin is cheaper but less refined than white heroin. Its color resembles dust or chocolate milk mix.
  • Black tar: This form has the most impurities because of how it’s processed. True to its name, black tar heroin looks like roofing tar, or a packet of very thick soy sauce.

Heroin is used in lots of ways. Injection is one of the most common methods, but you have to dissolve the product before drawing it up into a syringe. Depending on the type of heroin, you may need to heat it to dissolve it.

Smoking or snorting heroin usually takes less prep time, but generally, you can only snort powdered heroin.

Is heroin legal in the state of Oregon?

In 2020, Oregon passed Measure 110 to decriminalize drug possession. If you’re found with under 1 gram of heroin in your possession, you now get a Class E violation instead of a felony. This means you can pay a $100 fine or visit an addiction recovery center instead of spending time in jail.

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Depending on how you use it, heroin can go into effect immediately or within half an hour. You’ll probably first notice a rush of euphoria. Some people describe this as a warm, relaxed feeling, like resting on a cloud.

But what goes up must come down. After the “high,” you may experience less pleasant effects in your body and mind.

Physical effects

Psychological effects

  • slow or foggy thinking
  • lower inhibitions
  • “nodding off,” which is a half-conscious state where you go back and forth between awake and asleep

Heroin works quickly, but it doesn’t stay in your body long. The euphoria may last minutes, and the sedative effect can last several hours.

Even if you no longer feel heroin’s effects, its chemical byproducts might linger in your body a while longer — though the exact amount of time depends on how you took the drug and how long you’ve been using it.

Generally speaking, the detection window tends to be shorter if you inject heroin than if you snort or smoke it. Detection windows also tend to be shorter if you use heroin infrequently, compared with chronic or frequent use.

Regardless of how you took the heroin, it typically completely leaves your system within a few days at most.

Speedballing” refers to the practice of mixing heroin with a stimulant, such as cocaine, methamphetamine, or certain ADHD medications. The stimulant is meant to intensify heroin’s euphoria while masking its sedation effects.

Contrary to popular belief, opioids and stimulants do not cancel each other out. Instead, they have a tug-of-war effect on your body. For example, heroin could make your heart beat very slowly, but once it wears off, the meth in your system could push your heart into overdrive.

As you might imagine, this back-and-forth puts a major strain on your organs. Your risk of overdosing from a speedball is significantly higher than your risk of overdosing on either drug alone.


Mixing other substances that have a depressant effect, like fentanyl, alcohol, and benzodiazepines, can heighten heroin side effects, like slowed breathing. These combinations can also increase your risk of overdose.

Because heroin can cause physical and psychological dependence with repeated use, it can be very easy to develop an addiction to heroin, now called heroin use disorder.

According to the 2020 National Survey on Drug Use and Health:

  • 902,000 people in the United States ages 12 and older used heroin in the previous year
  • 691,000 people ages 12 and older met the criteria for heroin use disorder in the previous year

The survey doesn’t spell out whether these two categories overlap, and it doesn’t offer a specific percentage of the number of people who both used heroin and met the criteria for heroin use disorder in the previous year.

That said, these numbers do suggest a significant percentage of people who use heroin may live with heroin use disorder.

Heroin (opioid) use disorder is a mental health condition. Having this condition means heroin use has disrupted your life, and you have trouble controlling how much you use.

Here are some signs you may have heroin use disorder:

  • Heroin is often on your mind. Even when not using it, you might continue to think about the drug.
  • You have lost your job or failed classes due to your heroin use.
  • You keep using heroin even while recovering from serious health issues, like collapsed veins or pneumonia.
  • You need more and more heroin to feel the same high you used to.
  • When you stop using heroin for a day or two, you get withdrawal symptoms, like diarrhea and muscle pain.
  • You can’t stop using heroin, even though you have tried.

Though any form of heroin poses a risk of addiction, injecting heroin carries a higher risk, since your bloodstream can carry the drug directly to your brain.

Addiction isn’t heroin’s only long-term side effect. Chronic heroin use can cause a variety of physical and mental health issues:

Physical effects

Psychological effects

Taking more heroin than your body can handle can put you at risk of a potentially fatal overdose. This amount of heroin can depend on factors like your metabolism and the type of heroin you use.

Signs of a heroin overdose include:

  • weak pulse
  • blue lips or nails
  • slow, shallow, or absent breathing
  • very small pupils
  • difficulty staying awake

If you or someone you know shows these signs, call 911 immediately. In the U.S., all 50 states have good Samaritan laws that provide legal protection for the caller and the person who overdosed. In other words, you and your friend can’t get prosecuted for personal, low-level drug use as a result of calling for medical help.

As you wait for an ambulance to arrive, use any naloxone (Narcan) you have on hand. This emergency medication can temporarily reverse the effects of an opioid overdose.

Anyone can administer Narcan, so you don’t need to have a medical license or medical training. You can ask your local pharmacy for it to add to your personal first aid kit.

You can take steps to lower your risk of overdose and other side effects when using heroin. Here are a few safety tips:

  • Only use heroin in company: If you use drugs by yourself, nobody will be around to help if you have a bad reaction. It’s also a good idea to make sure at least one of you knows how to use Narcan in an emergency.
  • Use fentanyl test strips: These small paper strips can tell you whether your heroin has been cut with fentanyl. In one 2017 study, nearly 3 out of 5 people exposed to fentanyl-contaminated heroin were unaware of the contamination beforehand.
  • Do tester shots: Whenever you purchase from a new dealer or get a new batch, you may not know the drug’s strength. Consider using a tiny amount as a test shot (or test sniff) first, so there are no surprises.
  • Do not share needles: When you share needles, you also share any bodily fluids on the needle, like blood or pus. This puts you at risk of contracting the hepatitis C virus, HIV, and other infections.

If you’d like to get help stopping heroin use, you have a lot of options.


The Food and Drug Administration (FDA) has authorized three medications for treating opioid use disorders. These medications can help you with cravings and withdrawal symptoms:


Treatment for stopping heroin use may also involve counseling. Treatment goals may include:

Support groups

Joining a support group for people in recovery from substance use may also have benefits.

Narcotics Anonymous (NA) and Substance Abuse and Mental Health Services Administration (SAMHSA) offer free resources to get you started. You can join support groups at any stage of recovery. It’s never too early or too late to get help.

Emily Swaim is a freelance health writer and editor who specializes in psychology. She has a BA in English from Kenyon College and an MFA in writing from California College of the Arts. In 2021, she received her Board of Editors in Life Sciences (BELS) certification. You can find more of her work on GoodTherapy, Verywell, Investopedia, Vox, and Insider. Find her on Twitter and LinkedIn.