A comprehensive review of clinical trials suggests that cannabis products high in THC may provide modest, short-term relief for chronic pain, especially neuropathic types, but with notable side effects. In contrast, CBD-dominant products offer no clear advantages. Researchers call for more long-term studies to assess safety and efficacy.
Chronic pain, which persists for months or years, affects millions worldwide and drives interest in alternative treatments like cannabis. A recent analysis, published in the Annals of Internal Medicine, pooled data from 25 placebo-controlled randomized trials involving over 2,300 adults. Led by experts at Oregon Health & Science University, the study evaluated cannabis-based products varying in tetrahydrocannabinol (THC) and cannabidiol (CBD) content.
THC, known for producing a psychoactive high, appeared to drive the limited benefits observed. Products with higher THC-to-CBD ratios yielded small reductions in pain severity and slight improvements in physical functioning, such as daily activities. These effects were most evident in neuropathic pain, characterized by sensations like burning or tingling. For instance, oral THC-only formulations showed modest pain relief, with nabilone demonstrating a moderate impact and dronabinol offering minimal change. Nabiximols, combining THC and CBD, slightly eased pain but did not enhance function.
However, these gains were short-term, as most trials lasted only weeks. Products low in THC, including pure CBD options, failed to demonstrate meaningful pain reduction. On the downside, higher-THC items increased risks of adverse effects, including moderate to large rises in dizziness, sedation, and nausea. The researchers categorized products by THC:CBD ratios—high, comparable, or low—and by form, such as oral pills, mouth sprays, or skin topicals, as well as whether they were synthetic, purified, or plant-extracted.
An editorial from the UCLA Center for Cannabis and Cannabinoids underscores the inconsistency in results and ongoing safety concerns. It emphasizes the need for robust, extended research to inform patients, doctors, and regulators. Until then, cannabis's role in managing chronic pain remains tentative, balancing potential relief against evident risks.
