Consumption of Cannabis

How is cannabis consumed?

Cannabis is mostly consumed by combustion and in the form of a joint, through a bong or a pipe. Cannabis is also consumed through appropriate vapes, reducing the negative effects of combustion on the throat and lungs.

Cannabis does not need to be mixed with any other substance to be consumed. However, due to decades of illegality, high prices, and bad socially transferred practices in Europe, there is a predominant practice of mixing cannabis with tobacco. This increases risks of dependence and creates a ‘different’ high from when consuming cannabis on its own. Nicotine is a stimulant, a psychoactive substance, and highly addictive. When mixed with THC, there is an increased risk to develop dependence.

Cannabis is also being transformed in a wax like form and consumed through a practice known as dabbing. This form of cannabis contains very high levels of THC and is not advisable for people who have just started to consume cannabis or who have experienced negative effects following consumption.

Cannabis is also mixed with food (edibles) also through a process of heating cannabis known as decarboxylated. In this case the cannabis bud is heated and mixed with coconut or avocado oil. Through heating THC is released in the oil and good to mix with any type of food or beverage. Most popular are brownies and cookies. However, this oil could also be mixed with savoury food, such as pasta, chicken, salads etc.

Smoking cannabis is the most harmful method of consumption and is also directly linked with an increased propensity to develop dependence. The table below provides information on different onset levels applicable for different methods of consumption.


through a bong, pipe or joint (without tobacco)



Onset is short (2 minutes to 10 minutes)– therefore easier to refrain from continuing to consume if not liking the effects or if feeling too high



Damage to respiratory system, and other health problems associated with combustion


through a vaporiser



No combustion | Heating levels can be regulated to release different intensity of THC | Onset is short



This may be the most expensive method of administration, because of the price of the vaporiser. However, vaporising could be a cost-effective method in the long term




No Combustion | Least harmful method of consumption | Slow release and late onset



Onset level is slow (between 20 minutes and 2 hours) therefore it is important the person DOES NOT re-dose too early | The amount of cannabis and potency in the edible are important markers to ensure the person does not take more than what is intended (overdose)

Dosage and Duration

Depends on the person and on the levels of THC, however, these are some suggested measurements


Light dose: 0.05g

Common dose: 0.15g

Higher dose: 0.25g

Start: 2 – 10 minutes

Duration: 3 – 9 hours

EATING (Edibles)

Light dose: 2.5 – 5mg (THC)

Medium dose: 5 – 25mg (THC)

Higher dose: 25mg (THC)

Start: 20 – 120 minutes (depends on stomach content and body weight)

Duration: 3-9 hours

Tolerance Breaks

This is an important tool for people who consume cannabis on a regular or daily basis. If a person notices a sudden increase, it is important to look at the root cause of this increase and to adopt personal monitoring measures. People under the age of 21 should not consume high THC cannabis strains, and instead opt for CBD dominant strains. The method of consumption and onset levels are directly proportionate to potentially increasing levels of consumption, especially if tobacco is included in the equation.

What are the effects of cannabis?

Cannabis can help people relax and feel pleasantly sleepy and ‘stoned’, or in another setting, people use it to socialise, feel ‘high’ and laugh. It can make people clumsy with their bodies and words. Less like alcohol, cannabis also can alter the senses in unusual ways, so music, food, films, and computer games might seem different, more fascinating, and easier to feel immersed in. Cannabis has some side effects such as drying out the mouth and eyes (which can look red and feel itchy) and generating a strong appetite, ‘the munchies’. Especially for someone who has never taken cannabis before, the effects can be hard to predict and can be unpleasant for some people. It’s common for people to try cannabis and not want to use it again (DrugScience, 2023).

How harmful is cannabis use?

The relationship between harm and drug use is very subjective and depends on multiple variables such as how cannabis is used, intensity of use and type of cannabis used. Most people who try cannabis are not harmed by it at all. However, cannabis can have serious consequences in some people’s lives, particularly if they become dependent on cannabis. Regular users sometimes notice that cannabis is damaging their physical or mental wellbeing, others feel it holds them back from fulfilling their potential. As with any drug, the only relationship with cannabis that is 100% safe is avoiding it entirely. However, if somebody decides to consume cannabis, there are many important choices that can reduce the risks. These choices are linked to what type of cannabis is used, how frequently, and at what levels (DrugScience, 2023).

An analysis by Drug Science which added up and compared the harm caused by 20 different drugs in the UK placed cannabis roughly in the middle; it causes more harm to society than several other illegal drugs (mostly because there are many more users) but less harm to its users than the legal drugs tobacco and alcohol, both of which have a higher potential to cause serious illness and death (DrugScience, 2023).

What are the risks associated with cannabis?

The use of cannabis is predominantly experimental and lasts only for only a short period of time between late adolescence and early adulthood. However, a minority of people continue to use cannabis for recreational purposes and some developing problematic patterns of use. Problems are usually linked with regular, long-term and high-dosage cannabis use. These problems can include:

Poor Physical Health


chronic respiratory symptoms

Mental Health Issues


cannabis dependence and psychotic symptoms

Social and Economic Problems


arising from poor school performance, failure to complete education, impaired work performance or involvement in the criminal justice system

Reproductive Health


possible adverse effects on the foetus when consumed during pregnancy, and negatively impacts people having problems procreating

Various studies have shown that the early onset of cannabis use contributes to negative mental health and social outcomes. The risks may increase with the use of higher potency cannabis products (more than 20% THC). Studies have shown that concentrations of another component, cannabidiol (CBD), may attenuate some of the negative effects associated with a high dose of THC. In addition, cannabis use could also lead to acute symptoms requiring medical attention. However, despite its extensive use worldwide, deaths related to cannabis use are rare (EMCDDA, 2021).

The prolonged use of cannabis has been associated with increased risks linked with various acute and long-term health harms. These include acute intoxication with impaired cognitive, memory and psychomotor skills; increased involvement in motor-vehicle crashes and related injury and deaths; impaired neurocognitive and psychosocial functioning; mental health problems (e.g., psychosis and schizophrenia, depression and suicidal behaviours); cannabis use disorder/dependence; and select respiratory, reproductive, cardiovascular, gastrointestinal conditions. Some of these associations are stronger than others. Nonetheless, causality is not always easily established. The vast majority of people who use cannabis do not experience severe problems from their use, even with long-term exposure. The most serious problems arise in a sub-group of high-risk (e.g., intensive) users, where up to half are estimated to develop cannabis use disorder (CUD) (Fischer et al., 2022).

The Lower-Risk Cannabis Use Guidelines (2022) aim to provide an evidence-based approach to prevent harms associated with cannabis use, especially for those of a young age.

Lower Risk Cannabis Use Guidelines (LRCUG)

People who use cannabis need to know that there is no universal safe level of cannabis use: thus the only reliable way to avoid any risks for harm from using cannabis is to abstain from its use

Frequent cannabis use, and especially intensive use over longer periods, can lead to a ‘cannabis use disorder’ or cannabis dependence, characterised by symptoms such as cannabis craving, withdrawal, neglect of essential obligations, and limited capacity to control or reduce cannabis

People who use cannabis should exercise social considerations and responsibility in avoiding cannabis use that may result in harm to others

The initiation of cannabis use should be delayed until after late adolescence, or the completion of puberty to reduce development related vulnerabilities for harm

People who use cannabis should use ‘low-potency’ cannabis products (ie. Cannabis products with a balanced THC:CBD content ratio)

All main available modes of use options come with some risk for harm. Therefore, people who use cannabis should refrain from cannabis smoking and employ alternative routes of use for pulmonary health protection

If use occurs by inhalation, people who use cannabis should avoid deep inhalation, prolonged breath-holding or similar inhalation practices

People who use cannabis should refrain from frequent (e.g. daily or near-daily), or intensive (e.g. binging) cannabis use, and instead limit themselves to less frequent or occasional use

When possible, people who use cannabis should access legal and quality-controlled cannabis products and use devices

People who use cannabis experiencing impaired cognitive performance should consider temporarily suspending or substantially reducing the intensity (e.g potency and intensity)

Avoid driving a motor vehicle or operating machinery while under the influence of cannabis because of acute impairment and elevated risk of crash involvement, including injury and death (severity and duration of impairment is dependent on multiple variables)

It is prudent for people who intend to procreate and for women who are pregnant or breastfeeding to abstain from cannabis use towards reducing possible risks for reproduction and of health harm to the offspring, respectively

General caution should be attributed to the combination of other substances with cannabis. Mixing tobacco with cannabis increases risks related to dependence and health

Some specific groups of people are at an elevated risk for cannabis use related health problems because of biological pre-dispositions or co-morbidity. Cannabis use should be closely monitored or avoided

The combination of risk factors for adverse health outcomes from cannabis use further amplifies the likelihood of experiencing sever harms and should be avoided.

Lower Risk Cannabis Use Guidelines (LRCUG) (Fischer et al., 2022)

The safest way to use cannabis is not to use cannabis at all

However, if you still decide to use cannabis, the following aspects should be considered.

The effects of cannabis depend on the product and the person! This means some people may not tolerate cannabis.

Stomach Contents
What's in your stomach? How much cannabis your body absorbs from edibles varies depending on what is in your stomach and how your body metabolizes cannabis. Foods with high levels of terpenes (like mangoes and black pepper for example) may also impact how your body absorbs cannabis and can potentially change the effects.
Product Potency
The potency or intensity of cannabinoids in your product can affect your experience.
Frequency of Cannabis Consumption
Someone who has just started their cannabis journey will not have to consume the same amount as a daily cannabis consumer. When you consume cannabis regularly, your serving size will gradually need to increase to feel the same effects.
Everyone has a different metabolism. Cannabis is typically metabolized (broken down so the body can use it) and primarily absorbed in the lungs (when cannabis is smoked) and the liver (when cannabis is eaten). There is a reason why some people think edibles (such as gummies or baked goods) feel stronger and more potent than smoking cannabis. When you eat or drink cannabis products, THC is broken down in the liver and transforms into the metabolite 11-Hydroxy-THC (11-OH-THC), which is several times more potent than THC when it is smoked.
Cannabinoid and Terpene Profiles
With each cannabis cultivar (strain) comes a different combination of cannabinoids and terpenes. This means each cultivar will have a different effect on your body. It is also important to note that cannabis genetics vary from state to state. This means that a cultivar in one state might be totally different in another – even if they have the same name. Be sure to check the cannabinoid and terpene profiles, if available, to ensure you get the product you desire.
Set and Setting
Having a safe place to consume cannabis can influence your mindset. Being educated and empowered is essential to a safer cannabis experience. Therefore, where you consume, who you consume with (if anyone), and your state of mind when consuming cannabis – can all have an impact on your cannabis experience (Office of Cannabis Management NY, 2023).
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Part of responsible cannabis consumption is being aware of how you’re feeling. Before consuming, check in with yourself.

Adverse effects such as psychosis may occur in individuals with pre – existing mental health conditions that consume larger serving sizes of THC.

Be aware of how you feel before and after consuming cannabis.

Use caution if you drink alcohol or take other substances while you consume cannabis. Mixing cannabis with alcohol or other drugs (prescription or otherwise) could lead to a negative reaction such as dizziness, drowsiness, or sedation.

Setting intentions and visualising how you would like your cannabis experience to go (prior to consuming) can help you avoid anxiety and better embrace the present

What about psychosis?

To understand risks associated with psychosis one has to take a broad view, and primarily understand what psychosis is and what triggers its development (often in early adulthood). Someone with psychosis may experience paranoia (e.g. thinking people are plotting against you) delusions (e.g. thinking that you have a mission, and are being sent guidance through the radio) and hallucinations (e.g. hearing voices). Most people are very unlikely to ever get psychosis, but this depends on a combination of genetic make-up, stressors, and life practices.  In a world in which no-one used cannabis, people would still develop psychosis. Psychiatry explains that a psychotic episode is sometimes a one-off episode of a few days or weeks, sometimes someone dips in and out of periods of psychosis over their lifetime, sometimes it is more or less constant, and occurs with other problems (schizophrenia). All human beings have an inbuilt genetic risk for psychosis that ranges from virtually zero up to a maximum of more than 50% (the risk if your identical twin has schizophrenia). Then, on top of that inbuilt risk, things in our lives act as triggers towards or away from developing psychosis (Nutt, 2023).

Someone with a high genetic risk might only need a slight trigger, someone with a lower risk may need multiple triggers all added together for psychosis to emerge. These multiple triggers towards psychosis can include challenging, isolated lives, losing a parent, facing hostility (e.g. the stresses of being a gang-member or a struggling immigrant) stressful events (like having a baby), or even just living in a city or densely populated area. Furthermore, heavy use of high-THC cannabis (THC 20%+) seems to push people towards developing psychosis, making it appear earlier in predisposed individuals and exacerbating effects for people already diagnosed. Holistically, heavy and high THC use makes it harder for recovery (Nutt, 2023).

Nonetheless, studies have shown that overstating the role of cannabis in psychosis could be as harmful as ignoring it. Promoting a supportive, open, understanding family and social environment works against psychosis and for recovery, whilst a hostile, blaming response worsens the outcome. People in the process of developing schizophrenia often turn to cannabis, (rather than the cannabis causing the illness) possibly because it feels like it helps them in dealing with some of the symptoms. Understanding their perspective, recognising that cannabis alone is unlikely to have caused the problem and supporting them to live without cannabis (or first to replace high THC products with a more balanced THC:CBD ratio) is a more helpful response than angrily blaming them, and considering their life ruined (Nutt, 2023).

WHAT IS Cannabis use disorder?

In 2019, the Global Burden of Disease (GBD) study estimated that 0.6% of the European population met criteria for Cannabis Use Disorder, resulting in 158,000,000 disability adjusted life years. At the country level, vast differences in treatment rates are reported, with Bulgaria and Slovenia registering less than 2 treatment entries for cannabis problems per 100,000 adults and that of Malta registering more than 100 treatment entries per 100,000 adults. Interestingly, in countries where cannabis use is more common, such as in the Netherlands and Spain, the share of users meeting Cannabis Use Disorder criteria appears to be lower than in countries where cannabis use is less common, such as Malta and Hungary. Differences in treatment rates reflect different variables such as reporting methodology, different referral policies, a reduction of stigma around cannabis use and thus a higher willingness by cannabis users to seek help, and/or increased availability of treatment (Manthey, Freeman, Kilian, Lopez-Pelayo, Rehm, 2021).







Morally driven ideas that drug use and drug use disorders are a result of weak personal traits or family background have long been superseded by a recognition of the intricate realities linked with substance use and human behaviour. The World Health Organisation (WHO) recognises that substance use disorders are complex health conditions with psychosocial, environmental and biological determinants, which need multidisciplinary, comprehensive and public health-oriented responses from different institutions and organizations working together. There is an increasing understanding that rather than being a “self-acquired bad habit”, drug dependence is the result of a long-term interaction of biological and environmental factors including social disadvantages and adversities, and that it can be prevented and properly addressed to improve people’s health and public safety (WHO, 2022).

What is synthetic cannabis?

Synthetic cannabinoid receptor agonists (commonly referred to as ‘synthetic cannabinoids’) are a group of substances that mimic the effects of (THC). The synthetic cannabinoids bind to the cannabinoid receptors in the body. This is why these substances have been used to create a large range of ‘legal high’ products sold as legal replacements for cannabis. They are the largest group of new psychoactive substances monitored by the EMCDDA (EMCDDA, 2017).

The adverse health effects associated with synthetic cannabinoids are linked to both the intrinsic properties of the substances, what the body does to the substances, and to the way the products are produced. There has been a large number of non-fatal poisonings, and a smaller number of deaths are associated with their use. As some of these compounds are very potent, the potential for toxic effects appears to be high. These risks may be added to by the manufacturing process, which can lead to an uneven distribution of the substances within the plant material. This may result in some products containing ‘hot pockets’ where the cannabinoid is highly concentrated, leading to doses that are higher than intended and increasing the risk of serious adverse events. It is also possible that some of the adverse effects are due to mechanisms other than interaction with the cannabinoid receptors, for example by interfering with other physiological functions in the body. A recent systematic review of adverse events associated with synthetic cannabinoid products found that agitation, nausea and an abnormally fast, racing heartbeat were frequently reported poisoning symptoms; while serious adverse events — such as stroke, seizure, heart attack, breakdown of muscle tissue, kidney damage, psychosis and severe or prolonged vomiting — and associated deaths were less common (EMCDDA, 2017).

feeling unwell after consuming cannabis?

Problematic use of cannabis?