Overseas, particularly in North America, heroin is commonly laced with the powerful and dangerous opioid, fentanyl. This has resulted in over 100,000 deaths over the past several years. While New Zealand doesn’t currently have an opioid epidemic, it is still recommended that people using heroin consider fentanyl testing their drugs before using.

Key things to know

Consider carrying the overdose reversal drug naloxone with you. If someone is overdosing from heroin, it can save their life.

How to get naloxone

If injecting, visit your local needle exchange for new needles and information on how to be safer.

Safer injecting

Start with a lower amount and avoid taking more - especially if it's your first time or your tolerance has decreased

Safer using

Try to be with a sober person that knows the signs of an opioid overdose and can get help if needed.

Avoiding overdose

Use drug checking services to make sure it isn't mixed with something else.

Drug checking info

How does heroin make you feel?

Heroin is a potent opioid and can make people feel a sense of euphoria, warmth, heaviness in their body, nausea, and sleepiness. The initial effects or ‘rush’ can be short- lasting and varies depending on how you take the drug. When heroin is injected, the effects are felt almost instantly but don’t last as long compared to other methods like snorting. After this, people may experience several hours of after effects, especially sleepiness (this is sometimes called ‘the nod’).

Heroin can affect everyone differently depending on your individual body, how you use (smoking, snorting, injecting), how much you use, and how regularly you use. People who use heroin regularly can develop a tolerance to the drug and find that they need to use more and more to achieve the same euphoric effects as when they first started using. Homebake can also have different effects and doses to real heroin.

Remember, a low dose for one person can be a high dose for another as people’s bodies process drugs differently.

Keep in mind that when mixed with alcohol or other drugs or medicines, heroin may have different and more unpredictable effects. Heroin can also be cut with many other substances, which can change its effects or strength.

A Reddit user talks about their experience of snorting heroin for the first time:

“In addition to sedation I also experienced a bit of dulling effect, what some people would describe as being in the moment and not caring about anything”

Another Reddit user talks about how they feel when using heroin:

“At times it felt like I could see with my eyes closed. Didn't realize how surreal the visuals are with closed eyes, it felt insane. Does this happen to everyone? It was almost like tripping…I expected heroin to make me super tired and would let me slip into a nice slumber. I was certainly nodding hard but when I wanted to actually sleep I kept waking up constantly. The dreams were absolutely vivid and strange, couldn't tell what was real life tbh. Got very little real sleep.”

Pleasant Effects

Unpleasant Effects


Initial ‘rush’ straight after using


Sedation (‘the nod’)

Feeling of warmth/cosiness

Pain relief

Being in a ‘dreamlike’ state

Decreased anxiety

Temporary relief of stress or low mood

Vivid dreams


Itchiness (in one area or across whole body)

Sedation (‘the nod’)


Difficulty urinating

Loss of appetite


Changes in mood

Inability to orgasm

Erectile dysfunction

Pleasant Effects

Unpleasant Effects

Increased euphoria

Increased ‘rush’

Increased pain relief/feeling physical numb

Increased feelings of carelessness often described as feeling like ‘nothing matters’


Severe nausea


Severe or persistent itching

Increased sedation

Severe sweating or fevers

Mild dehydration

Slowed breathing

Irregular heartrate

Small pupils

Compulsion to re-dose

Disorientation or confusion



Pleasant Effects

Unpleasant Effects


Severe vomiting

Severely slowed breathing

Difficulty breathing


Blue lips or fingertips

Very cold and clammy skin

Pinpoint (tiny) pupils

Choking on vomit


Becoming unresponsive

Loss of consciousness

How much heroin do people usually take?

There are no publicly available tests to measure how strong your drugs are, so often people start low and go slow.

This information is not a recommended dosage amount. It can't take account of your specific circumstances. Drugs affect everybody differently, depending on things like your body size, any other drugs you’ve taken, what you have eaten, where you are, and how you're feeling. Find out more under the safer using section. 

Remember, drug checking can tell you what is in your drugs, but can’t tell you how strong they are.  

The information below is from other websites about how much people commonly use overseas. It is not a recommendation and typical usage in Aotearoa may be different.

How much heroin do people usually take - snorted (from

Light 7.5 - 20mg
Common 20 - 35mg
Strong 35 - 50mg
Heavy 50 - 75mg

How much heroin do people usually take - smoked (from

Light 5 - 15mg
Common 15 - 25mg
Heavy 30 - 50mg

How much heroin do people usually take - injected into a vein (from

Common 5 - 10mg
Strong 8 - 15mg

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How can you be safer when using heroin?

Heroin is a potent opioid and can be easy to overdose on. There are lots of things you can do to keep yourself safer when using heroin. Here are some things to consider:

Consider carrying the opioid overdose reversal drug naloxone. If you are using heroin, homebake or other opioid drugs often, you or the people around you may want to consider accessing the life-saving drug naloxone. In New Zealand, naloxone comes in the form of a nasal spray called Nyxoid, or in an injectable form. If someone is experiencing an opioid overdose, naloxone can reverse the effects and give you more time to get medical help. 

You can be prescribed either of these by a doctor, or you can buy Nyxoid as part of an emergency kit at some pharmacies. Some needle exchanges and opioid substitution treatment centres may be able to help you get naloxone.

We've got info on how to use Nyxoid nasal spray, and how to use injectable naloxone.

Test your heroin or homebake. It is important not to assume you know what is in your heroin or homebake. Heroin can be cut with several different things, and overseas heroin is often laced with other dangerous drugs such as fentanyl or novel benzodiazepines. Homebake can also have other ingredients from the conversion process left in it that can cause unpleasant effects.

You can take your heroin or homebake to a drug checking clinic that uses an FTIR spectrometer. These clinics will also use a fentanyl test strip to check for fentanyl in your drugs. You can use these strips at home as well by buying them online or in store at The Hemp Store.

Caution: Fentanyl test strips will not pick up on all fentanyl analogues. A negative test does not always mean you do not have fentanyl.

Take care if you are injecting heroin and visit your local Needle Exchange Programme. Injecting into the vein is a common method of using heroin. Injecting heroin or homebake delivers it faster to you blood stream, meaning the effects can be quicker but shorter-lasting. It is important to remember to take a smaller dose if you are injecting these drugs as the effects are stronger and you have a higher risk of overdosing.  If you are injecting heroin or homebake, make sure to use new, sterile equipment (including needles) every time you use. Sharing injecting gear can transmit blood-borne diseases like Hep C and HIV. Unsterile or used equipment can also cause abscesses and infections. You should also avoid injecting in the same site every time as this can cause damage and infection to the area. ‘Skin popping’ (injecting drugs just under the skin) can also carry a greater risk of infection than intravenous drug use.

You can get new, sterile injecting equipment from your local needle exchange. These programs also have lots of resources and information about safer injecting practices and heroin use.

For more information on how to be safer if injecting or snorting, see our drug safety section.

Start with a lower dose and avoid re-dosing. Heroin can have different effects on everyone. The effects may be particularly strong if it is your first-time using heroin or homebake. People can develop tolerance if they use it often, meaning they have to use more to feel the same effects. If you are new to using heroin or homebake, avoid basing your dose off what the people around you take. It is a good idea to start with a low dose and wait to feel the effects. As the after effects of heroin can last for several hours, re-dosing can cause dangerous levels of heroin in your body and increase your chances of overdosing. If you are using heroin orally, remember that it will take longer to feel the effects.

Caution: If you've used heroin regularly before, but have taken a break from using, start with a lower dose first as your tolerance can disappear after not using for a while.

Use less heroin if you are in an unfamiliar environment, even if you use often. There is lots of research that suggests that using heroin in an unfamiliar environment can increase your likelihood of overdosing. This is sometimes referred to as a ‘context effect’ and is seen in other drugs, even legal substances like caffeine. If you are a regular user of heroin, you may find you use in the same location, at the same time of day or with the same people. If any of these things change, it is very important to use less than you usually would, as a change in your normal environment can decrease your tolerance and increase your risk of overdose.

Have a sober buddy and make sure they know the signs of an opioid overdose. Overdoses can happen very quickly from all opioid drugs, including heroin and homebake. Overdoses can lead to death if someone does not get medical help, so it is a good idea to have a sober buddy around when you are using that can get help if something goes wrong. If someone is overdosing you should call 111 or get medical help immediately. The signs of an opioid overdose include:

  • Unconsciousness and the person doesn’t respond to their name or being touched
  • Difficulty breathing
  • Making choking, gurgling or snoring sounds
  • Blue lips, tongue and hands and their skin is cool and pale
  • Pinpoint pupils

Avoid taking heroin with alcohol or other drugs, especially depressants. People who combine heroin with other drugs have a higher risk of overdosing. Combining heroin or homebake with any drug, including alcohol and prescription medications, can lead to unpredictable and unpleasant effects. Combining heroin with other depressant drugs including opioids, alcohol, barbiturates, gabapentinoids, thienodiazepines, benzodiazepines, GHB/GBL and ketamine can be especially dangerous as they can increase the dangerous effects of heroin (e.g. slowing or stopping breathing). Using heroin with stimulants like cocaine or methamphetamine (known as speed balling) can also increase the likelihood of overdose and unpleasant effects.

Some research has shown that combining opioids with citrus fruits like grapefruit can also increase both the effects and the risk of overdose. There is limited research on combining heroin with many other drugs, so it is safest to not use heroin with other drugs or medicines.

For more information on how to be safer when using drugs and alcohol, see Safer using.  

To order self-help workbooks and other free resources for safer use, see Resources

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What do comedowns from heroin feel like, and how can you feel better?

The initial ‘rush’ of heroin is relatively short-lived, but you may feel after effects of tiredness, warmth, or relaxation for several hours after using. Once the after effects have worn off, some people will experience a heroin comedown. How severe your comedown is and how long the symptoms last can depend on how often you use, how much you use, how you use (ie. injecting, swallowing) and your individual body.

If you use heroin often and are cutting down, you may find your comedown symptoms are more severe, this is likely because you are experiencing withdrawal. For more information, see Managing withdrawal from drugs and alcohol.

If you...

  • Are nauseous, constipated or having changes in your appetite
  • Feel tired or lethargic
  • Have a headache or aches in your body or muscles
  • Have difficulty sleeping
  • Experience chills or cold sweats
  • Have cravings to use more heroin
  • Have a stuffy or runny nose (if snorting)
  • Have soreness or redness where you injected
  • Feel restless, agitated, anxious or low

Then try…

  • Get plenty of rest and sleep.
  • Remember to eat and drink plenty of water.
  • Get moving to release feel-good brain chemicals.
  • Reach out and talk with friends and whānau for support.
  • Relax and do things that you enjoy to take your mind off not feeling well.
  • Avoid caffeine, alcohol and other drugs.
  • Practise mindfulness and deep breathing, and try writing down your thoughts and feelings.

If any of these symptoms intensify or don't go away then call a doctor or Healthline 0800 611 116. They can talk you through the next steps.

If your symptoms worsen or you are with somebody who:

  • Becomes severely dehydrated
  • Has a high fever
  • Experiences suicidal thoughts
  • Has severe infection where you injected (red, swollen, very sore, blistering - accompanied by fever, stiffness, or chills)
  • Has seizures
  • Experiences delirium and or psychosis
  • Loses consciousness 

Call 111. These are signs that something more serious is going on. You or the people around you should act quickly.

A person on drugs forum describes his friends experience coming down after having a bender snorting heroin:

“He couldn't sleep very well, and when he got up and went to work, he felt like he got hit by a truck! TERRIBLE headache and nausea and wobbly legs all day.”

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What happens if you have too much heroin? 

Heroin is a potent drug and can affect everyone differently. It is easy to take too much heroin and end up feeling unwell or overdosing. How much will cause an overdose depends on your individual body, what kind of heroin you use (homebake, pure, black tar), how often you use (tolerance) and what environment you use in. Opioid overdoses can happen quickly, so it is important to know the signs and symptoms so you can get help as soon as possible.

You might feel nauseous, itchy, tired, disoriented or sedated. You might be constipated or have difficulty peeing. You might have a loss of libido, be unable or orgasm or have erectile dysfunction. You might lose your appetite, sweat more than usual or have smaller pupils than usual. 


  • Focus on breathing - try taking slow, deep breaths.
  • If you are able, call and talk to somebody you trust and ask them to help keep you calm.
  • Do not take more heroin, alcohol, or other drugs, as these can make you feel worse.
  • Move to somewhere quiet - try to sit or lie down and do something relaxing.
  • Drink water to stay hydrated.

If you're vomiting, experiencing symptoms of dehydration, are having trouble staying awake, are unable to urinate, feel very sweaty or have chills, have slowed breathing or feel like your heartrate is slower than usual or feel the need to take more heroin, call a doctor or Healthline (0800 611 116). You won't get in trouble if you tell them you've used drugs. They can talk you through the next steps.

If you're choking on your vomit, are very dehydrated, experience delirium or psychosis, become unresponsive or unable to wake up, have cold and clammy skin or blue lips/fingers, have a very slow heartrate or a weak pulse, have severely slowed breathing or difficulty breathing, have seizures or lose consciousness, these are signs of an overdose. You or the people around you should act quickly. Call 111 and administer naloxone if you have it.


A Reddit user talks about taking too much heroin:

“one time I knew I wasn't feeling right after the shot [of heroin], I was immediately all tingly and sh*t like pins and needles, super dizzy like Xanax dizzy…”

If you experience unexpected or concerning effects from heroin you can notify High Alert to help keep others safe.

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What are the long-term effects of using heroin?

Long-term heroin use can have many impacts on your brain and body. Heroin produces high levels of tolerance and dependance with regular use, which means it can be easier to develop an addiction to it than other drugs. It is important to remember that long term heroin use doesn’t affect everyone the same way. It can depend on your individual body, your physical and mental health, how you use, and how much you use.

Long-term heroin use can affect many parts of your body. If you inject heroin, you may be more likely to develop skin abscesses, collapsed veins and infections, or blood-borne diseases like HIV or Hep C if you share equipment or needles. If you smoke heroin, you may be more likely to have worsened asthma or develop lung diseases like Chronic Obstructive Pulmonary Disease (COPD), emphysema, or lung cancer. If you snort heroin, it can result in damage to your nasal passage and face.

For more information about how to be safer with different ways of taking drugs, see Safer using.

Regardless of how you use it, heroin and homebake can cause sexual dysfunction, affect the cycles of people who menstruate, cause kidney and liver diseases, increase your chance of developing pulmonary infections, reduce fertility and result in chronic constipation (and effects from this such as bowel obstruction).

Long-term heroin use can also affect your brain function and mental health. Heroin can deteriorate the white matter in your brain, leading to memory loss, difficulty making decisions, and difficulty controlling your behaviour or emotions. It can also cause neurological damage, which can be irreversible. Long-term heroin use can contribute to the development or worsening of mental illness. Such as depression, anxiety, psychosis, schizophrenia, and sleep disorders. People who experience mental illness may be more likely to develop a dependence to heroin, which can make understanding the relationship between heroin and mental illness harder.

If you use heroin regularly over a period of time, you can become physically and mentally dependant on opioids.

Heroin can cause some irreversible damage to your body and brain, especially if you are using large amounts regularly. However, it is also important to remember that some of the long-term effects of heroin use can reduce or go away completely once someone stops using.

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How do you manage withdrawal from heroin?

See the 'Making changes' page for more information on how to Manage withdrawal from drugs and alcohol.

People who use heroin regularly can develop tolerance and become dependant. This means that if you use regularly, or in large amounts it can be difficult to stop using suddenly. Many people find that withdrawal symptoms start between 24-48 hours after using and can last for a few weeks. How unpleasant your withdrawal symptoms are depends on how long you have used for, how much you use, how you use, and your physical and mental health.

If you are finding withdrawal too difficult on your own, you may want to consider getting support from a health professional. There are options like opioid substitution treatment (OST) that can help you transition onto prescribed opioids like methadone or buprenorphine. People using OST often have higher rates of success quitting heroin for good.

You might:

  • Have nausea, constipation, diarrhea stomach aches or changes in appetite
  • Feel tired or lethargic
  • Have a constant runny nose or watery eyes
  • Experience a headache or aches in your body or muscles
  • Have difficulty sleeping
  • Experience chills or cold sweats
  • Have cravings to use more heroin
  • Feel restless, agitated, anxious, low or hopeless

You can try:

  • Follow a tapering plan from a health professional to reduce your dose slowly 
  • Consider counselling, or support groups if feelings of anxiety and depression are getting worse
  • Lean on a support network of friends, family, and professionals
  • Stick to a routine - waking up, eating well, keeping active and rewarding yourself with things that bring you joy  
  • Practice mindfulness by writing down your feelings, doing breathing exercises or meditating

If your symptoms worsen or don't go away, experience an irregular heartbeat, have intense and lasting cravings to use more heroin, have vomiting or severe diarrhea, have insomnia, become severely constipated or have panic attacks, call a Doctor or Healthline (0800 611 116). 

If you are still not feeling well, think about:

  • Talking to your doctor about other medicines to help you get through withdrawal  
  • Talking to your doctor about rehab or withdrawal clinics in your area – visit Health Point to see what services are available.

If you're showing signs of bowel obstruction (very sore stomach, feeling of fullness, unable to poo), become severely dehydrated, have a high fever, experience suicidal thoughts or attempt suicide, have seizures, experience delirium or psychosis, become unresponsive or lose consciousness, these are signs you could be experiencing severe heroin withdrawal syndrome. You or the people around you should act quickly. Call 111.

For more information on getting support for drug and alcohol use, see Finding support.  

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How can heroin affect your daily activities?

Heroin and homebake are depressant drugs, they slow down your body functions, can make you sleepy and can cause disorientation or lack of coordination. The effects can kick in from just a few seconds after using (if injecting) and some of the after effects can last for up to 5 hours or more. How strong the effects of heroin are and how long they last for varies from person to person.

Heroin and homebake can cause you to feel like your body is heavy. It can cause extreme drowsiness, fuzzy thinking, loss of motor skills, and in some cases can lead to loss of consciousness. It is unsafe to drive or operate heavy machinery while using these drugs. Heroin can also make you more impulsive, impair your ability to think clearly, and cause rapid mood changes. This can make everyday interactions with other people difficult. Heroin can have intense effects on your brain and body that make it difficult to focus on anything else happening around you. Working or trying to complete tasks is often very difficult when high.

Will heroin show up on a drug test?

At some time in your life, an employer, a family member, or the NZ government, may ask you to take a drug test. It’s important to understand what drug tests can detect and what might happen if you fail one.

Heroin can be tested for in several ways and most drug tests will test for opioids. Heroin is usually tested for in urine as saliva and blood tests are less reliable. It is important to remember that every person’s body is different and will process drugs differently.

Generally, it is thought that heroin can be detected for about 1-2 days in urine (though some types of urine testing methods can detect it for closer to a week). Heroin can be detected for about 5-48 hours in blood and saliva and up to 90 days in hair. If you use heroin heavily or frequently, it may be more likely to show up for longer on these tests.

There are some medicines and foods that can cause a false-positive result for opioids on a drug test. Some research suggests that eating lots of poppy seeds can cause a false-positive for opioids. Medicines like dextromethorphan (in cough syrup), quetiapine and antibiotics such as levofloxacin and ofloxacin can cause false positives for opioids. As not all drug tests differentiate between opioids and heroin metabolites, if you are taking opioid based medicines like codeine, morphine, tramadol, or fentanyl you will likely test positive for opioids.

If you are using any medicine you are unsure about and are expecting a drug test, you can speak with your doctor beforehand.

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Is heroin illegal?

Heroin is considered a Class A Controlled Substance under the Misuse of Drugs Act in New Zealand. This means that buying, selling/supplying, possessing, or importing heroin is against the law. Homebake is sometimes sold as synthesized morphine and acetic anhydride , which  is considered a Class B Controlled Substance under the Misuse of Drugs Act. If homebake is sold fully converted, it is considered a Class A Controlled Substance. This means that it is also illegal to buy, sell, possess, import, and make homebake. 

To find out more about the law around legal and controlled drugs, including heroin, see Drugs and the law.

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