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Alcohol & Other Drugs

Learn About GHB, Ketamine and Rohypnol


Author: Canadian Institute for Substance Use Research

For references to the studies discussed in this info sheet, see the reference list.

What are GHB, ketamine and Rohypnol?

GHB,1 ketamine and Rohypnol2 are psychoactive (mind-altering) substances that affect how we think and behave. GHB and Rohypnol are depressants that slow down our heart rate, breathing, thoughts and actions. Ketamine is a hallucinogen that alters awareness, senses and perceptions. It also increases our heart rate and blood pressure.

Typically, these drugs are made in uncontrolled laboratories and come in various forms—pills, powder or liquid. GHB and Rohypnol are usually swallowed and ketamine is typically snorted (e.g., sniffed through a straw) but sometimes people inject it.


Why do we use these drugs?

While GHB, ketamine and Rohypnol were originally created for medical purposes, today they are most often thought of in terms of people having fun. Some people use GHB or Rohypnol to feel relaxed and sociable. Others use ketamine to experience unusual sensory perceptions. But like other drugs, they can be harmful.

Many people choose not to use GHB, ketamine or Rohypnol or to use the drugs in moderation, because being less in control of their body and behaviour increases the likelihood of accidents or making unwise choices such as having unsafe sex. Using the drugs may help us feel more outgoing at a party, but repeatedly using such substances to address social anxiety may lead to harms to our health or relationships.


What happens when we use these drugs?

When swallowed, GHB and Rohypnol are absorbed into the bloodstream through the small intestine and stomach. When snorted, ketamine is absorbed into the bloodstream through the membranes in the nose, and when injected, it goes directly into the bloodstream. Once in the bloodstream, the drugs travel to the brain.

GHB, ketamine and Rohypnol affect naturally-occurring chemicals in the brain that play a role in regulating our mood, energy and the way we experience the world. It is important to remember that these drugs have different effects on different people. Some people may feel happy and relaxed while others may feel anxious and restless. Some of the factors that influence how GHB, ketamine or Rohypnol will affect us include our

  • past experiences with the drug,

  • present mood and surroundings, and

  • mental and physical health condition.

Impact on well-being

Using GHB, ketamine or Rohypnol is always risky because we can never know for sure what we are putting in our bodies. Because the drugs are made or distributed in uncontrolled conditions, there is no way to know what’s mixed in them. And the people selling the drugs may say they are offering one kind of drug but actually giving another.

Small amounts of GHB or Rohypnol may help us feel more confident when socializing. But more than modest amounts increase the likelihood of drowsiness or even coma. Some people use ketamine because they like how it makes them feel detached from their body and environment. But being unaware of what is going on around us may put us at risk of injuries from falls and other accidents.

Over time, regular use of ketamine is linked with urinary and bladder problems. Drug-induced comas increase risk of negative effects on the brain, especially the developing brain.

Signs of overdose

Using GHB or Rohypnol involves a risk of overdose. How much and how often we use affects our degree of risk. And since it is not possible to know the purity and content of the drug, we can accidentally use too much. GHB and Rohypnol slow down heart rate and breathing. Signs of overdose include:

  • slow or no breathing

  • slow or no pulse

  • pale, cool skin

  • vomiting

If someone you know is showing signs of overdose, call 911 right away. Remain with the person. Try to wake the person up. If they do not regain consciousness, roll them onto their side into the recovery position so they won’t choke if they throw up.


When is using GHB, ketamine or Rohypnol a problem?

Using GHB, ketamine or Rohypnol is a problem when it negatively affects our life or the lives of others. Many of us may think this refers only to people who regularly use large amounts, but even a single occasion of use can lead to a problem. For instance, we may make a poor decision that results in problems with relationships or the law. What’s important to recognize is the potential for adverse consequences of use in any context and over time.

Drug use, especially regular use, by young people has particular risks. Like other psychoactive drugs, GHB, ketamine or Rohypnol can interfere with normal brain development. Early use can also interfere with developing normal patterns of social interaction with peers and have a negative impact on well-being.

One consequence that can develop is tolerance. This happens when it takes more of the drug to achieve the positive effects. If we regularly use GHB or Rohypnol, we are at risk of dependence. This means feeling like we need the drug to function and feel normal. While most people who use ketamine do not become dependent on the drug, those who use the drug frequently over a period of time may be putting themselves at some risk.

The reasons people use drugs influence their risk of developing problems. For instance, if a person uses a drug out of curiosity, only occasional or experimental use may follow. But when a person uses a drug to cope with a long-term problem such as social anxiety, then more long lasting and intense use may follow.

People who develop a dependence on GHB or Rohypnol may experience signs of withdrawal, including anxiety, nausea, headaches and disturbed sleep.

Mixing GHB, ketamine or Rohypnol with other substances

People sometimes mix one drug with another to experience different feelings or to offset the effects. For instance, a person may use a depressant such as Rohypnol to help them relax and rest after using a stimulant such as cocaine. But combining substances is risky as they can act in unexpected ways. The following are some common combinations and possible results.

Alcohol and other depressants

These are substances that slow down our heart and make us feel more relaxed. The effects can be greater when combined with other drugs in the same category. For instance, combining GHB with alcohol puts us at risk of overdose.


These are substances that increase our heart rate. Combining depressants such as Rohypnol with stimulants such as cocaine may cloud our judgment about how intoxicated we are, potentially leading to risky decisions such as driving a vehicle.


Combining cannabis with GHB, ketamine or Rohypnol may mask the effects of each drug. This may lessen our control over our behaviour, increasing the chances we may take risks that result in problems.


When prescription or over-the-counter medications are used with GHB, ketamine or Rohypnol, there is the potential for negative side effects or for the medicinal benefits to cancel out. Taking the time to read medication labels or consulting with a healthcare professional can reduce the risks.


How to make healthier choices about GHB, ketamine or Rohypnol

Whenever we choose to use GHB, ketamine or Rohypnol, it is helpful to know the steps we can take to ensure that our use is the least harmful possible. The following are some useful guidelines to follow.

Not too much. Managing the amount we use in a given period can help to decrease negative effects.

Tip: Buy less so you use less, and set a limit on how much you use at one time.

Not too often. Limiting how frequently we use helps reduce harms to ourselves and others over time.

Tip: Think about when you are likely to use and then try to break the pattern by consciously planning other activities (e.g., go to the gym or a movie with a friend).

Only in safe contexts. Making informed choices about where and with whom we use GHB, ketamine or Rohypnol helps to minimize harms.

Tip: When going out, stay in the company of trusted friends. That way you have someone to ask for help if a situation happens that feels unsafe or in case you get injured.


Are GHB, ketamine and Rohypnol legal?

GHB, ketamine and Rohypnol are controlled substances in Canada. Ketamine is legally available for veterinary and medical use. GHB is legally available for medical use. It is illegal to make, sell, buy or possess GHB, ketamine or Rohypnol. Offenders may receive a fine, a prison term and a criminal record that could affect their future employment, travel plans and educational opportunities.


What to do if you or someone you know wants to explore change

To better understand how substances play a role in your life, visit the You and Substance Use Workbook. This website also features detailed information on substance use and mental health.

You can also find information about a wide variety of substance use issues on the Centre for Addictions Research of BC website:


For information on treatment options and resources throughout BC, call the Alcohol and Drug Information and Referral Service at 1-800-663-1441. In Greater Vancouver, call 604-660-9382.


About the author

cisur logo

The Canadian Institute for Substance Use Research, formerly CARBC, is a member of the BC Partners for Mental Health and Substance Use Information. The institute is dedicated to the study of substance use in support of community-wide efforts aimed at providing all people with access to healthier lives, whether using substances or not. For more, visit

  1. gamma hydroxybutyrate
  2. brand name of flunitrazepam

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