Like any active drug or herbal medicine, cannabis use can have some side-effects including: Depression
Triggering of psychosis
(particularly in young people) Dizziness
Slower reaction times (dangerous if driving or operating machinery).
Addiction (this is less likely with the lower doses used for medical purposes compared with the higher doses generally used recreationally).
Smoking cannabis has some of the same risks of lung disease as tobacco. If you have a medical recommendation to inhale cannabis, a vaporiser is the safer and more reliable method.
Medicinal marijuana must not contain any pesticides, heavy metals, fungi, bacteria or other contaminants.