A total of 23 states and the District of Columbia allow the sale of marijuana for medical purposes. Despite these state laws, marijuana is not approved by the U.S. Food and Drug Administration as a prescription medication. Essentially, this means the U.S. government has not approved marijuana as safe and effective. But is it?
A new systematic review attempts to answer that question. The review, published in the Journal of the American Medical Association, includes 79 clinical trials and nearly 6,500 participants. It assesses the evidence for using marijuana to treat a variety of medical conditions including nausea and vomiting, pain, muscle spasms, sleep disorders, HIV and Tourette syndrome.
The results were mixed. While it found “moderate-quality evidence” that marijuana is effective in reducing pain caused by cancer and neuropathic pain, it is not effective in treating pain associated with fibromyalgia, rheumatoid arthritis or multiple sclerosis.
The review found that marijuana is moderately effective in reducing muscle spasms in patients with multiple sclerosis.
The researchers found “low-quality evidence” that marijuana was effective in treating other conditions including nausea and vomiting in patients undergoing chemotherapy, stimulating appetite in people with HIV, treating insomnia, and reducing the severity of tics in people with Tourette syndrome.
There was no evidence to show marijuana is effective in treating depression, anxiety, or glaucoma.
The review found some evidence that patients using medical marijuana experienced an increased risk of kidney and liver problems, and psychiatric disorders.
The take-home message here is a tricky one. If marijuana had gone through the standard FDA approval process, it would likely only be approved to treat a handful of medical conditions. Yet because states have removed restrictions around selling marijuana, it can be used for many more medical conditions.
There is another consequence to state’s regulating marijuana: the FDA is not able to regulate its purity and potency. A separate study published in the Journal of the American Medical Association found only 17 percent of marijuana products were accurately labeled. (The authors tested 75 products from three states, and readily admit the study did not include a random, representative sample.)
While medical marijuana may help some, there is not as much reliable evidence for using it compared to FDA-approved prescription medicines.