Low-Dose CBD Study Raises Questions on Pain Relief

A new study¹ from researchers at Aalborg University Hospital in Denmark has concluded that CBD offers no significant benefits for pain treatment. The trial, titled “Cannabidiol treatment in hand osteoarthritis and psoriatic arthritis: a randomized, double-blind, placebo-controlled trial” and published in the Pain Journal in June 2022, has drawn attention for its design choices and for the debate it is reigniting.

The researchers examined CBD’s efficacy as an analgesic therapy for patients suffering from hand osteoarthritis or psoriatic arthritis with moderate pain intensity, despite prior conventional pain treatment. The randomized, placebo-controlled study involved 129 participants. One group received 20 to 30 mg of synthetic CBD daily for 12 weeks, while the control group received a placebo.

After the trial, the authors concluded:

“We found neither clinically nor statistically significant effects of CBD for pain intensity in patients with hand osteoarthritis and psoriatic arthritis when compared with placebo. In addition, no statistically significant effects were found on sleep quality, depression, anxiety, or pain catastrophizing scores.”

For some, this might reinforce outdated notions that cannabis lacks medical benefits. For others, it raises a different question: were the study conditions appropriate to truly evaluate CBD’s therapeutic potential? A closer look suggests the trial’s parameters may have been inherently limiting.

Very Low CBD Dose

The CBD dosage used, 20 to 30 mg per day, was considerably lower than what is typically recommended for other therapeutic applications. For example, in schizophrenia research, CBD doses range from 300 to 1,200 mg per day, while for epilepsy, the FDA-approved dosing is 10 to 20 mg per kilogram per day.

Even a 10 kg child receiving epilepsy treatment would be prescribed at least 100 mg per day, which is more than triple the maximum dose in this pain study. This raises the question of whether such a low dose could realistically deliver measurable benefits for chronic, intractable pain.

Synthetic CBD Isolate vs. Full Spectrum

The trial used synthetic CBD isolate rather than a full-spectrum cannabis extract. Many studies have shown that full-spectrum formulations often provide better efficacy with fewer side effects due to the entourage effect, which refers to the synergistic interaction of cannabinoids and terpenes.

Pure isolates also tend to exhibit an inverted U-shaped dose-response curve, meaning efficacy peaks at an optimal dose and declines if the dose is too high or too low. This increases the likelihood that the chosen dose in the study sat outside the effective therapeutic range.

Low Bioavailability of CBD Tablets

The formulation may have further reduced CBD’s potential impact. Oral CBD tablets have relatively low bioavailability because of the liver’s first-pass metabolism. Research suggests oral forms may have as little as 40 percent bioavailability, meaning less than half of the already low dose may have reached participants’ bloodstream.

CBD Dosage Comparison

Swipe to scroll →

Was This Trial Built to Underperform?

While the study’s methodology met clinical standards, the combination of a low dose, synthetic isolate, and low-bioavailability tablet makes the lack of efficacy unsurprising. Whether these decisions were simply conservative choices or unintentionally set the trial up for underwhelming results is a matter for further debate.

What is clear is that CBD research remains highly sensitive to variables like dosage, formulation, and delivery method, and small changes can mean the difference between measurable therapeutic benefit and no observed effect.

References:

^{1. Vela, Jonathana,b,*; Dreyer, Lenea,b; Petersen, Kristian Kjærc; Arendt-Nielsen, Larsc; Duch, Kirsten Skjærbækd; Kristensen, Salomea,b. Cannabidiol treatment in hand osteoarthritis and psoriatic arthritis: a randomized, double-blind, placebo-controlled trial. PAIN 163(6):p 1206-1214, June 2022. | DOI: 10.1097/j.pain.0000000000002466}