Any side effects of medical cannabis are more likely to occur when your treatment first starts. In most cases the side effects are quite mild and wear off within a few days. It's important to document these and share any concerns with your consultant. Here's a list of typical side effects: Very common (affecting more than 1 in 10 people) Feeling dizzy or tired. Common (affecting less than 1 in 10 people) Feeling depressed or confused. Feeling over excited or losing touch with reality. Problems with your memory or having trouble concentrating. Feeling sleepy or giddy. Blurred vision. Eating more or less than usual. Changed sense of taste or a dry mouth. Constipation or diarrhoea. Feeling or being sick. Lack of energy or feeling weak or generally unwell. Feeling abnormal or drunk. Loss of balance or falling over. Uncommon (affecting less than 1 in 100 people) Seeing or hearing things that are not there (hallucinations). Believing ideas that are not true. Feeling that other people are against you. Thoughts of suicide. Fainting. Changes in pulse rate, heart rate or blood pressure. Tummy pain