GHB, GBL, and 1,4-BD can be very easy to overdose on because there is a small difference between a common dose and a dangerous dose.

Key things to know

GHB, GBL and 1,4-BD are similar-feeling drugs with different dosages.

GBL and 1,4-BD are turned into GHB in your body after you take it. Both GBL and 1,4-BD may be easier to overdose on than GHB.

Drug differences

The high from these drugs takes 15–45 minutes to kick in and lasts for 1–4 hours.

What to expect

Avoid mixing with other drugs, especially ones that slow your body down like alcohol.

Safer using

They can make you feel horny - so plan beforehand (e.g. talk about consent with your partner, use condoms).

Sex on GHB

Drug checking can help you find out if you have GHB, GBL or 1,4-BD, or if these are mixed with another drug.

More info

How does GHB/GBL/1,4-BD make you feel?

These are three similar-feeling drugs that have very different dosages.

The effects of GHB, GBL and 1,4-BD usually start 15–45 minutes after taking them and last for 1–4 hours. They slow your body down and may make you feel euphoric, sexually aroused, groggy and nauseous. Some people describe the feeling of as similar to being drunk.

GBL and 1,4-BD are turned into GHB in your body after you take them. All three have different dosages - and just a millilitre can be the difference between overdosing or not. 

  • GBL comes on faster than GHB and is stronger, meaning it's easier to overdose on than GHB
  • 1,4-BD has a slower onset than GHB but can be more potent. Because it's slower acting than GHB, people may be tempted to take more, increasing the risk of overdose

You can't tell the difference between these drugs just by looking at them, and one may be sold as another. It is important to know whether you have GHB, GBL or 1,4-BD when deciding what dose to take. Drug checking can help you find out what you have.

It is best not mix alcohol with GBL/GHB/1,4-BD as it increases unpleasant effects and your chance of overdose. Remember, a low dose for one person can be a high dose for another as people’s bodies process drugs differently

An Erowid user talks about a friend’s experience using GBL:

“My friend drank a ‘capful’ of GBL – an amount he had done before with no problems – as I drove him to a club where we were going, he told me he was ‘really starting to feel it’ and then IMMEDIATELY became incoherent. It happened so quickly I honestly thought he was messing around with me – until he started drooling on himself. He did not respond to my voice – so I stopped the car and an ambulance was called – he vomited twice in my car not knowing what was going on at all – during the next 10 minutes, his seizure remained but he started moving less and less – like he was passing out.”

Pleasant effects

Unpleasant effects


Socially confident




Increased sense of touch and sound

Increased connection to others



Drowsy or groggy

Agitated and irritable


Difficulty concentrating or thinking


Stumbling, tripping or falling over

Making risky decisions or judgements

Having mood swings

Seeing double or having blurred vision

Memory loss


Slurred speech



Engaging in sexually risky behaviour

Pleasant effects

Unpleasant effects

Increased feelings of wellbeing

Feeling very relaxed

Feeling ‘out of body’

Increased sexual arousal

Increased euphoria

Pleasant hallucinations


Very agitated or irritable 

Increased mood swings

Severely nauseous


Increased risky decisions or judgements

Increased anxiety

Increased memory loss

Disturbing hallucinations

Falling asleep suddenly

Increased lack of coordination

Difficulty moving your body

Difficulty breathing or slowed breathing

Heart palpitations

Feeling cold and clammy

Pleasant effects

Unpleasant effects


Severe tremors

Severe loss of control of body movements

Severe vomiting

Difficulty breathing

Chest pains

Severely anxious

Severe panic attacks

Severely paranoid

Slipping into a ‘g-hole’ or coma-like sleep




Losing consciousness

How much GHB, GBL, or 1,4-BD do people usually take?

It is important to know whether you have GHB, GBL, or 1,4-BD when deciding what dose to take. You can't tell the difference between these drugs just by looking at them, and one may be sold as another. Drug checking can help you find out what you have.

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 GHB do people usually take - swallowed (from

GHB is usually taken as a liquid, shaken immediately before being taken to make sure it is evenly distributed.

Light 0.5 - 1g
Common 1 - 2.5g
Strong 2.5 - 4g


Warning: Risk of death above 10g

Tripsit have a tool to covert these weights to liquid.

How much GBL do people usually take - swallowed (from

GBL is usually taken as a liquid, shaken immediately before being taken to make sure it is evenly distributed.

Light 0.3 - 0.9mL
Common 0.9 - 1.5mL

1.5 - 3mL

Warning: Doses over 2mL can induce heavy sleep.



How much 1,4-BD do people usually take - swallowed (from

1,4-BD is usually taken as a liquid, shaken immediately before being taken to make sure it is evenly distributed.

Light 0.5 - 1mL
Common 1 - 2.5mL
Strong 2.5 - 4mL


Warning: Doses above 4mL can induce heavy sleep and doses above 6mL can lead to poisoning.

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How can you be safer when using GHB/GBL/1,4-BD?

An addictions worker talks about the importance of being careful with doses because GBL is much stronger than GHB and you can't tell the difference by looking at them.

If you are not sure whether you have GHB, GBL or 1,4-BD than always dose it as if it is GBL. 

There are many other things you can do to keep safer when using GHB, GBL and 1,4-BD.

Take care and wait at least two hours before re-dosing. 
GHB, GBL and 1,4-BD are most commonly mixed into a drink and swallowed, which releases them into your body slower than by snorting or injecting. If you swallow GHB, GBL or 1,4-BD, try to wait for 2 hours before re-dosing as you may not feel the effects right away. This is especially important for 1,4-BD as it might take longer to feel the effects than if you were taking GHB or GBL. If you plan on re-dosing, consider separating out your doses into small containers and use a phone alarm to schedule when you'll take them. Reduce the amount you're re-dosing with each time to lower your risk of overdose.

A person who uses GHB talks about how they measure their doses

I use one of those small soy fish containers from the sushi shop to carry my doses. I fill up half of the fish, which is about 1.5mL of GHB, and it wont melt it like other plastics!

Be aware that other methods of using GHB, GBL and 1,4-BD (snorting/injecting) can increase your risk of overdose. 
Snorting or injecting GHB, GBL or 1,4-BD will deliver these drugs to your body much quicker, which can increase your chances of overdosing. These methods can also cause damage and infection to your body. If you do chose to snort or inject these drugs, use new and sterile utensils and equipment every time. 

Avoid mixing GHB/GBL/1,4-BD with other drugs, especially alcohol and depressants. 
GHB and GBL have very strong effects, and when mixed with other drugs, they can become more dangerous. This is especially the case for alcohol and other depressant drugs as effects become more intense and the risk of overdose increases.

GHB, GBL and 1,4-BD can make you horny - so plan how to keep yourself safe! 
You may be more likely to engage in risky sexual behaviours when using these drugs. Or you may end up in situations where you are not sober enough to enthusiastically gain or give consent. It is good to think about how you might keep yourself and others safe before you use. For example, using condoms to prevent pregnancy and STIs. It can also be a good idea to colour liquid GHB/GBL/1,4-BD with blue food colouring. This way, it will not be mistaken for water and added to your or someone else’s drink without knowing.

Test your GHB, GBL and 1,4-BD to make sure it isn't mixed with other drugs. 
You can test GHB, GBL and 1,4-BD yourself with some reagent tests or at a drug checking clinic with a spectrometer. How reliable these tests are can depend on how concentrated your drug is. If it has been mixed with lots of water, it may be hard for the spectrometer to detect it.

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

A Reddit user talks about their experience with GHB:

“It can make you tired, sort of feels like a mix between alcohol and MDMA with a vastly different character to it, in my experience anyway, dosage wise I’m not sure, only took it for the first time this year so just start very low if you’re concerned.”

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What do comedowns from GHB/GBL/1,4-BD feel like, and how can you feel better?

The effects of GHB, GBL and 1,4-BD are relatively short-lived compared with other drugs. The peak effects of GBL last for about 1–2 hours but this is slightly longer for GHB and 1,4-BD, with effects completely wearing off after about 4 hours. GHB and GBL comedowns are generally not severe, and effects usually pass within a day.

Some people report using GHB and GBL to come down off other drugs, like MDMA. The effects of a GHB or GBL comedown from this type of use can be unpredictable.

If you...

  • Have trouble sleeping
  • Feel very hungry
  • Sweat or feel very hot or very cold
  • Have trouble concentrating or thinking
  • Feel agitated, irritable, anxious, low or paranoid
  • Feel tired
  • Have headaches
  • Have bad dreams or nightmares

You can 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:

  • Experience psychosis
  • Feel suicidal 
  • Have chest pains
  • Have trouble breathing
  • Have a seizure
  • Lose consciousness

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

 The Erowid vault talks about someone’s experience with a high dose of GHB at a festival:

“He had a terrible hangover the next day and claimed that he felt negative after-effects for more than 2 weeks after the event, particularly during the first week, he felt foggy, had difficulty concentrating, and somewhat ‘anhedonous’ meaning he didn’t enjoy anything.”

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What happens if you have too much GHB/GBL/1,4-BD?

You might feel confused, have memory problems, have jitters or feel anxious, feel nauseous or dizzy, feel disinhibited or make risky decisions, feel anxious or paranoid, feel unable to stay awake, stumble or fall over or experience unwanted sexual arousal. 

Try these things at home:

  • 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 GHB/GBL/1,4-BD, caffeine, 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 your symptoms get worse or don't go away, or you experience rapid personality changes, vomiting, tremors, panic attacks, heart palpitations or feeling breathless, 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 have severe muscle jerks or tremors, lose you control of your body movements, choke on vomit, have difficulty breathing, have chest pains, become unresponsive, slip into a ‘g-hole’ or coma-like sleep, experience psychosis, have a seizure, lose consciousness, these are signs of an overdose. You or the people around you should act quickly. Call 111.

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

A Reddit user gives their advice to people looking to take GHB:

“It’s addictive, destructive, and extremely easy to overdose with. It’s nearly killed me on more than one occasion involving my bad choices. If you decide to use it, just remember it deserves great respect. Inform yourself about dosages, interactions, and I remember to always set a timer when I dose. When you’re high on this stuff, you have no concept of time at all, and it’s super easy to double dose and never even think about it. A double dose can put you in the hospital. Also remember no alcohol at all. Don’t let anyone talk you into drinking with it. Just be safe.”

GHB, GBL and 1,4-BD can be very easy to overdose on because there is a small difference between a common dose and a dangerous dose. Visit tripsit for more information on dosing GHB, GBL and 1,4-BD.

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What are the long-term effects of using GHB/GBL/1,4-BD?

Most people who use GHB, GBL or 1,4-BD will only use them from time to time and are unlikely to develop addiction or dependence to the drug. However, people who use these drugs often or for a long period of time may experience long-term issues.

Even if you only use GHB or GBL a few times a year, it’s important to be safe to avoid long-term issues. One of the bigger concerns with these drugs is that they can result in sexually risky behaviour. GHB and GBL are often used as party of chemsex or party n' play, or to heighten other sexual experiences. These drugs can cause poor judgement and result in an increased risk of transmitting sexually transmitted infections like HIV because of not using condoms.

A one-off bad experience or overdose on GHB or GBL can cause permanent damage to your brain and body. This includes affecting your memory, the way you learn and your mood.

Tripsit says that "1,4-BD also carries the potential for more health risks than GHB, such as liver damage and neurotoxicity."

When using regularly, GHB and GBL can change the way your brain works – you may be more forgetful and more impulsive. You can become addicted to GHB and GBL and experience unpleasant effects when you stop taking it. Overall, the long-term effects of GHB, GBL and 1,4-BD have not been well researched, so it can be hard to predict what might happen if you use this drug regularly for a long time.

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How do you manage withdrawal from GHB/GBL/1,4-BD?

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

It is not common to become addicted to GHB, GBL or 1,4-BD. However, if you use these drugs regularly, especially in high doses, you may experience withdrawal symptoms when you want to stop using or take a break. Withdrawal symptoms can start 1–6 hours after the last dose of GHB/GBL/1,4-BD wears off and can last from 5–15 days.

In people who have used GHB or similar drugs regularly for a long time, ‘cold turkey’ withdrawal can sometimes be dangerous. It is important to speak with a medical professional first if you are worried about withdrawing from these drugs.

You might:

  • Experience diarrhea, constipation (or a change in bowel movements) or nausea
  • Have aches and pains
  • Feel agitated, irritable, jittery, anxious or low
  • Feel sweaty or feel very hot or very cold
  • Have difficulty sleeping

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 low mood 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.
  • Practise mindfulness by writing down your feelings, doing breathing exercises or meditating.

If your symptoms get worse, or you experience tremors, severe agitation, aggression, suicidal thoughts or irregular heartbeat, hallucinate or have a panic attack, call a doctor or Healthline (0800 611 116). You can talk to your doctor about:

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

Acting violently, having severe changes in heartrate, attempting suicide, having disturbing hallucinations, losing consciousness or experiencing psychosis, call 111

These are signs you could be experiencing GHB/GBL withdrawal syndrome. You or the people around you should act quickly.

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

One Reddit user talks about running out of GHB and experiencing withdrawal symptoms:

“Been doing G for about 2 years, but twice a day every day for the last 8 months. I ran out, first symptoms: diarrhea, cold sweats, then got worse! At night, severe psychosis and hallucinations where I would see and hear people talk to me, I had to ask my wife what was real and what wasn’t.”

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How can GHB/GBL/1,4-BD affect your daily activities?

Even at lower doses, GHB, GBL and 1,4-BD are drugs that can affect your day-to-day activities. The effects usually last up to 4 hours, after which you may start to experience a comedown period. The effects may last for a much longer period if you use GHB or GBL regularly, mix it with other drugs or take very large doses.

GHB, GBL and 1,4-BD can cause dizziness, extreme sleepiness, impaired judgement, and confusion, and people can appear ‘out of it’. Because of this, it is unsafe to drive, operate machinery or do things that need concentration or motor coordination. These drugs can cause euphoria, increased sexual arousal, forgetfulness, slurred speech and risk taking, which can make interacting with others difficult. It may also mean you do or say things or act in ways that are out of character.

If you take GHB/GBL, will it show up on a drug test?

GHB and GBL are usually tested for using hair, urine, saliva (spit) or blood. However, these drugs may not be tested for often as they can only be picked up on in a very short window (1–2 days) and can be unreliable.

GHB and GBL testing windows can change depending on how much you have taken, how often and your individual body. However, it is thought that GHB and GBL can be found for 12 hours in urine and 8 hours in blood – these are the most accurate tests. Saliva tests detect GHB and GBL for up to 6 hours but are mostly used as a secondary test after a urine sample. Hair sample tests can detect GHB and GBL for up to 30 days, but they are not very reliable.

If you believe you have been given GHB or GBL without your consent (sometimes called getting ‘roofied’), you may be asked to have a test to see if it is in your system. If you have been given these drugs without your knowing and are expecting a drug test for work or court, you can speak to a medical professional or Police about your next steps.

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Is GHB/GBL/1,4-BD illegal?

GHB, GBL and 1,4-BD are illegal  in New Zealand are Class B controlled drugs under the Misuse of Drugs Act. Buying, possessing, selling, making, or importing these drugs is against the law. In some countries, GHB or GBL are used for medical purposes, but this is not the case in New Zealand.

GHB/GBL/1,4-BD can sometimes be used for sexual experiences. However, giving any drug including GHB, GBL or 1,4-BD to someone without their consent is against the law.

You can also get in trouble with the law if you are found to be impaired while driving using GHB, GBL or 1,4-BD.

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

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