Risks of getting stoned

How you use cannabis can cause you problems.

Perhaps the biggest problem with cannabis is the way it's taken by smoking, especially if its mixed with tobacco. It's important to understand that cannabis can have both good and bad effects at the same time - for example good effects due to the drugs it contains (such as making asthma better) and bad effects because of the way it's used (smoking, making asthma worse). As always, there are things you can do to reduce the problems


How much is too much?
First time?
Does smoking cannabis cause cancer?
Toking methods / equipment
Eating cannabis / overdose?
Welcome to the underground

How much is too much?

The first thing to know about cannabis is you can't take enough of it to kill you, it's impossible to overdose fatally. Most people can take a lot of cannabis and simply get very, very stoned but for some having too much can become quite unpleasant.

As with any kind of drug taking, taking a lot quickly isn't the same as taking a lot slowly. If you take a lot quickly it is possible to have a "whitey", meaning you pass out and feel sick. Others may find the sensation of being stoned unpleasant, perhaps leading to attacks of paranoia, this will be worse if it happens suddenly. For a very few using a lot quickly might potentially be dangerous psychologically.

It isn't possible to say how much is too much, it depends to a large extent on the individual person, small people need less than large people for example. Experienced users will know how to handle things, new users may not be so good at it.

It's important to remember that not everyone reacts in the same way to cannabis. For a few people even one smoke can make them feel unhappy, but for most having too much simply sends them to sleep.

Also remember that different types of cannabis have somewhat different effects, so it's not easy to say how much is too much.

The best advice is to take it slowly, beware of devices like bongs with "shot holes" if you're not used to it.

First time?

If you're new to this, make sure the place you're getting stoned in is familiar and comfortable. Getting stoned can mean it gets harder to judge the actions of others and being stoned in an unfriendly or threatening place can be very scary.

Only get stoned with people you know and trust and preferably with someone who's experienced and knows the ropes, although always rely on your own judgment if you think you've had enough..

If you don't enjoy the effects of cannabis, don't keep trying in the hope you will. It's not for everyone and there's nothing wrong with saying "no thanks".

If you've smoked cannabis the effects will start to wear off after anything from half an hour to three hours although if you've eaten it things may take a bit longer.

You don't have to smoke every time some is offered, learn your limit - experienced smokers will know this and true friends won't encourage you to have more if you say "no thanks"

Young people under 18 are best advised not to get stoned - at least not very often. This is good advice not only for cannabis but also for any drug. Getting stoned is an adult thing, don't give it to kids under 15.

Does smoking cannabis cause cancer?

Smoke of any kind is probably not good for you because it contains microscopic particles called "PM10's" which have been linked to cancer and other illnesses. These are particles which are small enough to get right down into the lungs.

There have been claims made by anti-drug campaigners - and even the British government's agencies that cannabis smoke is up to four times more dangerous than tobacco due to the amount and nature of the tars it contains. It is certainly true that cannabis smoke contains a lot of cancer causing chemicals.

However there are studies which seem to show THC (one of the compounds in cannabis) actually inhibits cancers and that smoking cannabis is not associated with lung cancer - see here. Despite the claims cannabis smoke seems to be far less dangerous than tobacco - providing you don't smoke it with tobacco of course and despite all the hype, pure cannabis use doesn't seem to be linked to lung cancer.

But the more smoke you breathe in and the longer you hold it in your lungs, the greater the risk.


If you've ever scraped out a used bong you'll know about the tars in cannabis smoke. The heavy fractions of tars - the gooey dark brown stuff - will be caught in a pipe or water pipe and It's probably not a good idea to breathe these in.

It's important to know that a roach on a joint is not a filter and won't stop these tars.

If you're going to smoke cannabis - breathe in as little smoke as possible and allow the smoke to cool. The less smoke you breathe in the better.


The biggest health risk most people who use cannabis run is the use of tobacco to roll joints. Until fairly recently joints were the normal way to use cannabis, although this is changing now. UKCIA is running a campaign called "Toke Pure" which aims to encourage users to avoid tobacco, there are a lot of very good reasons to do this.

Never smoke cannabis mixed with tobacco.


Toking methods

Some ways to toke such as bongs involve fast intense hits of smoke. This means you will get very stoned very quickly. Although many people enjoy this, some people may react badly to it.

If you're not used to cannabis, it's good advice to take things slowly - avoid smoking methods that involve a "shot hole" or some other way of suddenly breathing in a large amount of smoke

Don't take in huge gulps of smoke and hold it in your lungs for a long time.

See UKCIA's How to smoke cannabis section


Plastic bottles, rubber hoses, or PVC should not be used to smoke cannabis as these all give off toxic fumes when hot. Of course, if plastic is used for things that don't get hot, there's no problem.

Another problem is aluminum drinks cans or tinfoil which are often used to make pipes or as a gauze. Aluminum vapourises at a low temperature and so you'll breathe it in as you toke and this might lead to very serious mental health problems such as Parkinson's. Always use a steel gauze or steel cans for making pipes.

Getting stoned too fast can lead to a whitey - you won't enjoy that. Don't burn cannabis in plastic or rubber, acrid foul tasting smoke is a sign that this is happening. Never smoke with an aluminum pipe.

Eating cannabis

Eating cannabis (called "ingesting" it) avoids all of the problems connected with smoking. When cannabis is legalised this may become the normal way of using it, rather than smoking. As long as you know how much you're taking and you know the cannabis is clean, it's probably the best way to consume it.

The most obvious problem is how much to eat? This of course depends on the strength of the cannabis you cook with and there's no way of knowing that because of prohibition - cannabis is illegal and unregulated.

The important thing to know about ingesting cannabis is that it takes a while to have any effect. Nothing will happen for an hour or so, but when it does it can be far more potent than smoking the same amount and the effect can last for ages. Many people say eating cannabis produces a more "trippy" effect, it can be very intense if you overdo it.

When prohibition ends, cannabis foods will no doubt be available in known doses, just like alcohol is today. Until then we have to live with this uncertainty.

If you eat or drink cannabis foods, take it slow, nothing will happen for at least an hour or so. For more information see the "How to eat cannabis" section.


Although there's not the risk of overdose as such - you won't die - some people react quite badly to getting stoned, especially if they have a lot all at once. For someone with - or who is vulnerable to - a mental health problem a heavy dose of cannabis might cause serious problems.

Because of the law, eating it is probably the most risky dose-uncertain way to do it, although it does avoid the problems of smoking.

Don't eat cannabis without a little bit of planning, including where you are and who you're with.

Because of prohibition, strengths are uncertain and there is the additional risk of contamination Contamination is a serious problem and the best advice is only to cook with cannabis grown by yourself or someone you know.

Welcome to the underground

It's important to realise that cannabis you buy is supplied by a huge unregulated illegal economy and the so called "black market" weed and hash may be very contaminated. In the UK, this not only means "soap bar" (which should always be avoided anyway), but it may possibly apply to any hash or weed unless you know who grew it or you grew it yourself.

Eating/drinking cannabis can be dangerous due to the presence of contaminants and/or pathogens and given the high possibility of adulterants, especially in imported cannabis, you should really think twice before using a nonsmoking method unless you know the cannabis is grown and stored correctly.

f you smoke cannabis, use a pipe or similar and don't mix it with tobacco. Particularly if you're not used to it, don't smoke huge amounts in one go - be wary of bongs and pipes with "shot holes".

There are claims that crops in the producer countries are being sprayed by the US government (and probably by ours as well) with cancer causing herbicides. In addition large scale commercial grow-ops may be using large doses of organophosphate insecticides (OPs). It is not known what effect smoking OP's will have.

There is no reliable way to clean contaminated cannabis, for example, boot polish will survive washing. If your grass comes from sprayed crops as part of the eradication programme there's nothing you can do about that.

It's worth remembering that this added danger is considered a measure of "success" by the government.

It's generally good advice not to buy cannabis supplied by organised crime, so get to know someone who grows at home or grow yourself - but be aware that it's illegal to do so and the law can be very harsh.