CBD and fibromyalgia: what a 200-patient trial found
No effect of CBD on fibromyalgia has been shown. In a Danish trial of 200 patients followed for 24 weeks, 50 mg of CBD a day was no more effective on pain than a placebo. The French national health authority (HAS) judges the data insufficient to recommend cannabinoids for this condition, and over-the-counter CBD products are not medicines.
Key takeaways
- Inserm estimates that about 1.6% of the French population has fibromyalgia.
- On a 0 to 10 scale, pain dropped 0.4 point with CBD and 1.1 points with placebo in the trial published in 2026 in the Annals of the Rheumatic Diseases.
- Most earlier studies tested THC or nabilone, a synthetic derivative, and the quality of their results is rated low.
- The HAS guidelines of July 2025 place adapted physical activity first and do not recommend cannabinoids.
- The French medical cannabis pilot scheme did not include fibromyalgia among its conditions.
Fibromyalgia in brief
Fibromyalgia brings together widespread, long-lasting pain, fatigue and sleep problems. According to the Inserm collective expert review published in October 2020, it affects 1.6% of the population in France, mostly women. At the time, the report described its management as "not codified" and aimed mainly at symptoms.
This has partly changed. The French national health authority (HAS) published guidelines on diagnosis and treatment strategy on 10 July 2025. First-line care rests on adapted physical activity, learning to manage the condition and staying in work. Certain antidepressants and antiepileptics at low doses come second, and opioids are kept for occasional, cautious use.
The 2026 Danish trial: a negative result
The strongest study on the subject was published in the Annals of the Rheumatic Diseases, online in August 2025 and in the March 2026 issue. It is a randomised, double-blind trial conducted at a specialist centre in Denmark. In a randomised trial, chance decides who receives the product; in a double-blind one, neither patients nor clinicians know who receives what.
The team screened 273 people and enrolled 200. For 24 weeks, 100 took 50 mg of plant-derived CBD a day in tablet form and 100 took a placebo. The primary outcome was the change in pain, rated from 0 to 10 on a standard fibromyalgia questionnaire.
By week 24, average pain had dropped 0.4 point in the CBD group and 1.1 points in the placebo group. The 0.7-point difference favours placebo and is statistically significant. Side effects, mostly mild, were spread evenly between the groups. The authors conclude that their findings "do not support" CBD at 50 mg a day as an add-on painkiller in fibromyalgia.
The trial's limits are a single dose and a single centre in one country, and it tells you nothing about other doses or forms. None of the reviews cited by the HAS included a trial of CBD alone of this size, and this one found no effect.
What earlier studies found
Until 2025, most of the data concerned products that contain THC.
In a Dutch study published in Pain in 2019, 20 patients inhaled, during a single session, three pharmaceutical cannabis varieties, one of them rich in CBD, plus a placebo variety. On spontaneous pain, none outperformed placebo. The authors also observed that CBD increased blood THC levels and reduced THC's pain-relieving effect.
A systematic review published in 2023 in Biomedicines combined four randomised trials and five observational studies, with 564 patients in total. Most of the trials tested nabilone, a synthetic cannabinoid similar to THC, or inhaled cannabis. The authors rate the evidence for a short-term reduction in pain as "low quality".
The HAS examined this work in the evidence report behind its guidelines. It cites a Cochrane review that covered only two trials and 72 participants and found too little data to reach a conclusion. It also notes that the European rheumatology body (EULAR) does not recommend cannabinoids because the data are lacking.
| Study | Product tested | Participants | Result on pain |
|---|---|---|---|
| Pain, 2019 | Inhaled cannabis, one CBD-rich variety, single session | 20 | No better than placebo |
| Biomedicines, 2023 (review) | Mostly nabilone and cannabis | 564 | Low-quality evidence, short term |
| Annals of the Rheumatic Diseases, 2026 | CBD alone, 50 mg a day, 24 weeks | 200 | Placebo slightly better |
How to read results of this kind is explained in our article on what clinical studies really say about CBD.
The position of the French authorities
The HAS concludes that the data are insufficient to recommend cannabinoids in fibromyalgia. Its text adds that over-the-counter CBD products have not been assessed for quality, composition or harmfulness, and that they do not have the status of medicines.
Medical cannabis is a different question. The pilot scheme of the ANSM, the French medicines agency, covered five conditions, among them refractory neuropathic pain, painful spasticity in multiple sclerosis and some drug-resistant epilepsies. Fibromyalgia was not on the list. A permanent framework is being put in place, and our article on the rollout of medical cannabis tracks the timetable.
Epidyolex is the only CBD-based medicine authorised in France. It is prescribed in rare, severe forms of epilepsy: Lennox-Gastaut and Dravet syndromes, and tuberous sclerosis complex. That framework is described in our update on Epidyolex and the research.
What we can say, and what we do not
A freely sold CBD product may not claim any effect on a disease, and the research would not support such a claim anyway: the only large trial of CBD alone is negative. We therefore present none of our products as an answer to fibromyalgia.
If you take medication, two precautions apply. CBD can interact with some medicines, including antiepileptics, which are a second-line option in fibromyalgia; the mechanism is explained in our article on CBD drug interactions. Any decision about your care is one to discuss with your doctor.
Frequently asked questions
The available data do not show it. In the 2026 Danish trial, which followed 200 patients for 24 weeks, pain dropped less with CBD (0.4 point) than with placebo (1.1 points). The HAS judges the data insufficient to recommend cannabinoids.
About 1.6% of the population, mostly women, according to the Inserm collective expert review published in 2020.
No. The five conditions covered by the ANSM pilot scheme included refractory neuropathic pain and left out fibromyalgia, as the HAS notes in its 2025 guidelines.
Adapted physical activity, learning to manage the condition and staying in work come first. Certain antidepressants and antiepileptics at low doses come second. Cannabinoids are not recommended because the data are insufficient.
Written by the Phytogrammes team
Each journal article draws on cited primary sources: ANSM, EFSA, EUR-Lex and peer-reviewed publications. Product profiles are distinguished from documented laboratory results. Our approach.
Article published on . CBD is not a medicine.