Cannabis or marijuana is a drug that can be grown as a plant. It is commonly smoked or inhaled, but can also be baked and eaten.

In the short term, cannabis can make you feel relaxed, talkative, and it can also make sensory experiences feel more intense, for example, music may sound better. In higher doses, people may feel sick or faint, confused or paranoid. It's not safe to drive after having cannabis.
Long-term use of cannabis can affect your ability to learn and concentrate, and users may find that they feel demotivated or uninterested in other things going on in their lives.

People who start using cannabis at a young age or who use it regularly are more likely to become dependent on it. This can lead to problems with sleeping, irritability or restlessness when stopping using cannabis. If you smoke cannabis along with tobacco you will also be more likely to experience some of the health problems associated with smoking, including heart and lung problems. Smoking cannabis during pregnancy can also affect a baby's development.

There are links between regular cannabis use and some mental health problems. People who use cannabis more regularly and from a younger age can be more likely to experience delusions and hallucinations. This is where they see or believe things that are not real. The risk of these long-term effects is higher if someone in your family has had problems with delusions or schizophrenia (a mental health problem which is commonly linked to delusions and hallucinatory experiences).  

HIV, hepatitis C and other blood infections can be passed on by sharing needles or syringes. This includes sharing needles to inject certain drugs.
When you use a syringe to inject drugs, some of your blood will flow back into the syringe. A needle and syringe that someone else has used can contain any blood viruses that they have. If you then use the same injecting equipment, you can inject these viruses into your bloodstream.
Sharing other equipment for injecting including the water used to flush out syringes, spoons or other containers or filters, can also be a way of passing on HIV and other viruses.


If you inject drugs, avoid sharing needles, syringes and other injecting equipment. Some places will provide you with new needles and a place to safely dispose of old ones. Use clean boiled water to flush out syringes and dispose of injecting equipment safely. You might also consider taking PrEP to prevent HIV transmission. Speak to a healthcare worker, if you want help to stop using drugs.