Cannabis is the most common illegal drug in the UK. Whether you plan to bake some hash brownies, swan off to Amsterdam, or to grow your own – make sure you know the facts about cannabis first.

Boy rolling a spliff

"Rollers rights, mate."

What is cannabis?

Cannabis is a plant containing the drug THC — the stuff that gets you high. Basically, the higher the concentration of THC in cannabis, the more stoned you get.

It comes in three different forms:

Grass, marijuana or weed: the dried leaves and flowers of the plant.

Hash or solid: a sticky brown resin that’s scraped off cannabis buds and moulded into a block.

Cannabis oil: a thick liquid made from either hash or grass.

How do you take cannabis?

Cannabis can be taken in a variety of ways:

  • Rolled up with tobacco and smoked as a joint
  • Smoked using a bong
  • Smoked using a pipe
  • Using a vapouriser
  • Eaten, usually in cakes and brownies, or stirred into yoghurt
  • Inhaled in a ‘hot box’, which is a room filled with cannabis smoke

Why do people take cannabis?

How cannabis affects you varies; it depends on how much you take and if you’ve taken it before. Common experiences are:

  • Feeling chilled out and relaxed, i.e. stoned
  • Finding EVERYTHING hilarious
  • Being very chatty
  • Having deep theories about life and the universe, and seeing hidden meanings in everything, including kids’ TV shows
  • Becoming more aware of your senses – you love music more than ever before, and you start rubbing cushions cos they’re oh so soft
  • Feeling like time has slowed down
  • An overpowering desire to eat everything you can get your hands on (AKA the munchies)

Are there any bad side effects?


  • Coughing – if you’re smoking it
  • Losing your short-term memory
  • Headaches
  • Feeling dizzy and confused
  • Low blood pressure, which can make you feel faint
  • Clumsiness
  • Vomiting, especially if you mix it with alcohol or other drugs


  • Smoking weed can lead to respiratory problems and, if you mix it with tobacco, can cause cancer
  • There are links between smoking cannabis and low sperm counts in men, and sometimes lower fertility in women
  • Heavy smoking damages the immune system
  • Using it a lot can affect your concentration
  • It can make asthma worse

How long does it take to get high?

If you smoke it, the effects are pretty immediate, but if you eat it in a brownie it can take half an hour or longer to kick in.

What’s the comedown like?

The day after you’ll probably feel tired and a bit foggy. You may have trouble remembering things, your body may feel stiff, your mouth dry, and your eyes itchy and red.

What’s a bad trip?

Not everyone enjoys cannabis. Rather than chilling you out, it can make your heart race; you might panic, feel confused, start hallucinating, or just feel crap. These effects can last for a couple of days after you’ve taken it.

What’s a whitey?

A whitey is when cannabis makes you feel really faint and nauseous. You go pale (hence the name), feel cold, sweat, shake, vomit and sometimes pass out.

It can happen because you’re tired, hungry, dehydrated or you’ve just smoked too much.

Is cannabis addictive?

Cannabis itself isn’t physically addictive. However, if you smoke cannabis in a spliff stuffed with tobacco you’ll soon become addicted to nicotine – just like anyone who smokes cigarettes. The feeling of being stoned also has the potential to be psychologically addictive.

Should I use a cigarette filter in my spliff?

Probably not. You may think it will make your joint healthier because less tar gets through, but it stops the THC as well. You’ll just have to smoke a lot more to get any effect – not good. Use a folded cardboard roach instead.

Does cannabis cause schizophrenia?

Cannabis doesn’t cause schizophrenia directly, and most people won’t experience any mental health problems because of it. However, if you’re already pre-disposed to schizophrenia, taking cannabis can make it more likely you’ll develop it. There’s no exact way of telling who’s likely to get schizophrenia, but you should be ultra-careful about using cannabis if:

  • Someone in your family has had schizophrenia or another psychotic disorder
  • You’ve had schizophrenia before, as cannabis can cause a relapse

The risks are higher if you used cannabis a lot in your teens.

How can I reduce the risks if I take cannabis?

Cannabis is often seen as natural and ‘safe’, but there are risks. With cannabis you need to be especially careful with your lungs:

  • Put as little tobacco in your spliff as possible.
  • Don’t hold the smoke in – especially if you’re mixing it with tobacco – it just deposits more tar in your lungs.
  • Don’t drive when you’re high.
  • If you’re using a pipe or a bong keep it clean.
  • If you’re eating cannabis remember it takes longer to work than smoking it. If you get impatient and have too much you’ll just pull a whitey.

What if I get caught taking cannabis?

Cannabis is a class B drug, so if the police catch you with weed they have three options:

  1. Give you a cannabis warning – the police will keep a record of the fact you were caught with cannabis, but it won’t go on your criminal record.
  2. Issue a Penalty Notice for Disorder (PND) – the police can fine you £80 on the spot if you’ve already had a cannabis warning. If you pay it within the next 21 days you won’t get a criminal record.
  3. Arrest you – if you’ve already had a cannabis warning and a PND, the police will take you to the station, where you could either get another cannabis warning or PND, a caution (which will go on your criminal record), or be charged with possession.

You can get a maximum of five years in prison and a fine for possession.

If you’re caught supplying, making, or growing cannabis, you can get up to 14 years in prison.

Photo of rolling a spliff by Shutterstock

Next Steps

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Updated on 29-Sep-2015