Over the past years, the use of medical cannabis is becoming of interest in the medical world. It has been recognized as an alternative treatment and has been legalized in many countries for medical purposes. Although there have been numerous claims of what cannabis can do, conclusive findings regarding its properties remain elusive. While access to cannabis is high, information accessible to consumers is still limited. Countless past studies have been done on cannabis’ effect on health issues. Hence, the purpose of this literature review was to conclude and summarize the past findings on the therapeutic effect of cannabis, focusing on the Delta-9-Tetrahydrocannabinol (Δ9-THC) and Cannabidiol (CBD), on the following medical conditions; chronic pain, opioid use disorder (OUD), obesity, sleep disorders, cancer, post-traumatic stress disorder (PTSD), psychosis, epilepsy, traumatic brain injury (TBI), Parkinson’s disease (PD), and Alzheimer’s disease. The risks of cannabis consumption for these issues were also identified. The results suggested that cannabis has the ability to assist in chronic pain, OUD, sleeping disorders, and Alzheimer’s disease. Regarding PTSD, psychosis, and TBI, there have been findings only about CBD which showed a beneficial effect on the diseases. It could not be concluded that cannabis can be used to treat obesity, cancer, epilepsy, and Parkinson’s disease due to limited evidence. The majority of the studies also demonstrated that high doses of CBD and low doses of THC should be used to maximize benefits. More clinical trials and research need to be conducted as there are research gaps and insufficient information in various subjects.
