Side Effects

July 2, 2013

3.2 approved shutterstock_116261065Like any drug, medical marijuana can have side effects. It’s important to be aware of these when deciding whether it’s an appropriate treatment for you.

Because THC is psychoactive, its use may result in acute psychosis, including feelings of paranoia, delusions, and distorted sensory perceptions. Evidence suggests that individuals with schizophrenia have a higher likelihood of suffering adverse psychiatric effects.

Precautions for the use of medical marijuana are based on evidence of potential side effects in affecting the following areas.


Generally, it is not recommended that any medicinal product be smoked. However, smoking is a common delivery method for the THC and CBD found in medical marijuana. There are negative pulmonary side effects related to smoking marijuana. In vitro studies provide strong evidence that smoked marijuana is carcinogenic, although epidemiological evidence is inconclusive. Studies suggest that heavy marijuana smokers have decreased lung function and often experience symptoms of bronchitis and chronic coughs, implicating it as a long-term risk factor for chronic obstructive pulmonary disease.


Upon taking marijuana, some patients experience a rapid heart beat (tachycardia). This side effect can be problematic or even dangerous for patients who have angina or a pre-existing heart condition. Smoking marijuana also causes blood vessels to expand (vasodilation), resulting in reddening of the eyes and affecting the body’s ability to counteract low blood pressure.

Central nervous system

Side effects to the central nervous system include intoxication-like symptoms such as drowsiness, dizziness, and getting a “high” sensation (elation and laughing). Cognitive impairment such as reduced short-term memory and difficulty concentrating have also been reported. In addition, marijuana use impairs psychomotor performance; driving under the influence is not advised.


Marijuana use has been implicated in chronic liver disease. A significant association has been seen between its use and severe liver fibrosis in patients with hepatitis C.


Epidemiological, clinical and non-clinical studies agree that marijuana and THC have negative reproductive side effects on sperm count, motility, and morphology.

Pregnancy and breastfeeding

Use of marijuana should be avoided if you are planning a pregnancy, pregnant or breastfeeding because of potential risks to your fetus or child.

Comments are closed.