Understanding the Side Effects of Medical Cannabis

patient and doctor

Medical cannabis has been used for various health conditions, including managing pain, anxiety, and seizures, among others. Unlike traditional medication, cannabis may cause side effects that are often misunderstood by patients. It’s important to be aware of these side effects to make informed decisions about your treatment. In this blog post, we’ll discuss the common side effects of medical cannabis and how to manage them. 

Dry Mouth and Eyes

One of the most common side effects of medical cannabis is dry mouth and eyes. Cannabis affects the glands that produce saliva and tears, causing them to slow down. This leads to a dry feeling in your mouth and eyes. To manage dry mouth, you can try drinking more water or using saliva substitutes. For dry eyes, eye drops or artificial tears can help relieve discomfort.

Dizziness and Lightheadedness

Cannabis can also cause dizziness and lightheadedness, especially in patients who are not used to the psychoactive effects of cannabis. This side effect is usually temporary and goes away as the body adjusts to the medication. However, if you experience severe dizziness or fainting, it’s important to seek medical attention immediately.

Anxiety and Paranoia

Cannabis can also produce feelings of anxiety and paranoia, especially in high doses or sensitive patients. If you experience these side effects, it’s important to reduce your dosage or talk to your healthcare provider about changing your medication. It’s also important to note that cannabis may interact with other medications that you’re taking, so always disclose your usage to your doctor.

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Increased Appetite

Cannabis has also been shown to increase appetite, commonly known as the “munchies”. While this may be beneficial for patients with eating disorders or undergoing chemotherapy, it can also lead to overeating and weight gain. To manage this side effect, patients can try eating healthy snacks and meals, exercising, or talking to a nutritionist.

Sleepiness and Fatigue

Another common side effect of cannabis is sleepiness and fatigue. This may be beneficial for patients with insomnia but can be problematic for patients who need to stay alert and focused. Patients can manage this side effect by consuming cannabis at lower doses or at night, when it doesn’t interfere with daily activities.

Make informed decisions about your treatment

Medical cannabis may produce side effects that vary from patient to patient. It’s important to recognize these side effects to make informed decisions about your treatment. Dry mouth and eyes, dizziness, anxiety, increased appetite, and sleepiness are among the most common side effects of medical cannabis. Patients can manage these side effects by adjusting their dosage, changing their medication, or using home remedies. Always consult with your healthcare provider before starting treatment with medical cannabis to ensure you’re getting the best possible treatment for your condition. 

For more information, visit the TGA – Medical Cannabis Hub


  1. Lintzeris N, Mills L, Suraev A, Bravo M, Arkell T, Arnold JC, Benson MJ, McGregor IS. Medical cannabis use in the Australian community following introduction of legal access: the 2018-2019 Online Cross-Sectional Cannabis as Medicine Survey (CAMS-18). Harm Reduct J. 2020 Jun 8;17(1):37. doi: 10.1186/s12954-020-00377-0. PMID: 32513180; PMCID: PMC7278204.
  2. Breijyeh Z, Jubeh B, Bufo SA, Karaman R, Scrano L. Cannabis: A Toxin-Producing Plant with Potential Therapeutic Uses. Toxins (Basel). 2021 Feb 5;13(2):117. doi: 10.3390/toxins13020117. PMID: 33562446; PMCID: PMC7915118.

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