The two main active chemicals in cannabis are:

  • Cannabidiol, also known as CBD, is a sedative, meaning you will feel relaxed, sleepy and it can reduce pain. In some countries it is used as a medicine. For CBD oil to be legal in the UK, it must contain no THC.
  • Tetrahydrocannabinol, better known as THC, is more hallucinogenic, which means that it has an effect on the mind, altering the user’s perception of reality. You might see, hear or feel things in a different way to normal.

Skunk cannabis is very high in THC, and very low in cannabidiol. This means that users experience less of the relaxing effect of cannabis, and instead get unpleasant and a much more unpredictable effect on the mind.

It is thought to be responsible for rising levels of mental health problems among users – such as depression, anxiety and psychosis.

Most cannabis being sold illegally in the UK is super-strength skunk.


The effects can be pleasant or unpleasant. Skunk may magnify stress and tension and leave users feeling uncomfortable and paranoid, as well as feelings of anxiety and suspicion. Some people have one or two drags on a joint and feel light-headed, faint and sick. This is sometimes called a ‘whitey.’

Harm reduction

If you want to reduce the amount of cannabis you smoke, there are various ways to do this:

  • Try writing down why you want to change
  • Plan how to cope with withdrawal
  • Have a back- up plan


YHSMS has produced two informational leaflets on cannabis and edibles so you can make an informed decision.

Find out more

There is a lot of different information about cannabis on the internet; it can be difficult and time-consuming to sort through it all and find need-to-know stuff.

Take part in the activities below to help you to understand the risks and decide whether or not you want to use it.

If you do want to use it, then you can find out the best ways to keep yourself safe.

There are also some links to further resources that can be used to access more information about drug use.

The Young Hackney Substance Misuse Service is open to anyone aged under 25. It’s free and confidential.  They can give you advice and support if you’re worried about your own substance use. They’ll also help if you’re worried that a friend or family member has a problem with drugs or alcohol.

Alternatively you can visit the FRANK website for completely confidential support.