THC Cannabis Oil for Fibromyalgia: A Controlled Trial
What Researchers Found About Fibromyalgia and Cannabis
The Study at a Glance
Published
Pain Medicine, 2020
Researchers
Federal University of Santa Catarina (Brazil)
Study Type
Randomized Controlled TrialParticipants
17 patients · 8 weeks
Key Finding
In this 8-week controlled trial, women with fibromyalgia taking THC-rich cannabis oil showed significantly improved quality of life scores compared to placebo. Pain, fatigue, ability to work, and overall well-being all improved—with no intolerable side effects.
Key Finding: In this 8-week controlled trial, women with fibromyalgia taking THC-rich cannabis oil showed significantly improved quality of life scores compared to placebo. Pain, fatigue, ability to work, and overall well-being all improved—with no intolerable side effects.
What Researchers Studied About Fibromyalgia and Cannabis
Fibromyalgia is a challenging condition characterized by widespread pain, fatigue, and reduced quality of life. Standard treatments often provide limited relief.
This Brazilian study tested whether a THC-dominant cannabis oil could help women with fibromyalgia living in difficult socioeconomic circumstances—a population that often struggles with access to effective treatments.
The trial used a THC-rich formulation (24.44 mg/mL THC with minimal CBD) to evaluate real-world effectiveness.
How This Randomized Controlled Trial Was Conducted
Researchers conducted a double-blind, placebo-controlled trial:
• 17 women with fibromyalgia • 8-week treatment period • THC-rich cannabis oil (24.44 mg/mL THC, 0.51 mg/mL CBD) • Started at low dose (~1.22 mg THC/day) with gradual increases based on symptoms • Measured using Fibromyalgia Impact Questionnaire (FIQ) • Five assessment visits over the study period
Fibromyalgia Treatment Results
The Main Results:
- 1Significant improvement in overall Fibromyalgia Impact Score (p=0.005 vs placebo)
- 2"Feel good" score improved significantly
- 3Pain scores improved significantly
- 4Ability to work improved significantly
- 5Fatigue improved significantly
- 6No intolerable adverse effects reported
By the Numbers
| Statistic | What It Means |
|---|---|
| p=0.005 | statistical significance vs placebo for overall improvement |
| 8 weeks | treatment duration |
| 17 | women with fibromyalgia participated |
| THC-dominant | formulation used (24.44 mg/mL THC) |
statistical significance vs placebo for overall improvement
treatment duration
women with fibromyalgia participated
formulation used (24.44 mg/mL THC)
What This Means for Fibromyalgia Patients
This small but rigorous trial provides encouraging news for fibromyalgia patients:
What improved: • Overall fibromyalgia impact (significant vs placebo) • Pain levels • Fatigue • Ability to do work • General sense of well-being
Safety findings: • No intolerable adverse effects • Gradual dose titration helped minimize side effects • Started low (about 1mg THC) and increased as needed
Important context: • This was a small study (17 participants) • Used THC-dominant oil, not CBD-only products • Participants were able to adjust their dose based on response • 8-week duration shows sustained benefit
Practical takeaway: THC-rich cannabis products may help fibromyalgia symptoms when standard treatments fail. Starting with a very low dose and gradually increasing appears to be an effective approach.
Quick Answers: Fibromyalgia and Cannabis
Direct answers based on the findings of this study:
Research Summary: Answers are based on published peer-reviewed studies and represent research findings, not medical recommendations. Individual results may vary. Always consult a healthcare provider before making treatment decisions.
Does marijuana help fibromyalgia?
Yes, THC oil improved symptoms in one trial. A 2020 clinical trial found THC oil significantly improved fibromyalgia symptoms including pain, fatigue, and ability to work over 8 weeks compared to placebo (Chaves et al., Pain Medicine).
Source: Chaves et al., Pain Medicine, 2020 (PMID: 33118602)
What helps fibromyalgia pain naturally?
Medical marijuana is one option that research supports. A controlled trial found THC oil significantly reduced fibromyalgia pain and improved quality of life compared to placebo when used over 8 weeks (Pain Medicine, 2020).
Source: Chaves et al., Pain Medicine, 2020 (PMID: 33118602)
How much THC for fibromyalgia?
Start very low—about 1mg THC—and increase slowly. A successful fibromyalgia trial used this "start low, go slow" approach with THC-rich oil over 8 weeks, achieving significant improvement while minimizing side effects.
Source: Chaves et al., Pain Medicine, 2020 (PMID: 33118602)
This is educational content, not medical advice
The research summarized here is for informational purposes only. Individual results may vary, and what works in studies may not work the same way for everyone. Always consult with a qualified healthcare provider before making changes to your treatment plan or starting medical cannabis therapy.
Important Limitations
This study has some caveats to keep in mind when interpreting the results:
- Small sample size (17 participants)
- All-female population—may not generalize to men
- Specific socioeconomic context (low-income area)
- Single formulation tested
- Longer-term effects unknown
The Bottom Line on Cannabis for Fibromyalgia
This controlled trial adds to evidence that THC-rich cannabis oil can meaningfully improve fibromyalgia symptoms. Women in the cannabis group showed significant improvements in pain, fatigue, ability to work, and overall quality of life compared to placebo—all with no intolerable side effects. While the study is small, it reinforces findings from larger observational studies and provides hope for fibromyalgia patients who haven't found relief with standard treatments.
Do You Qualify for Medical Marijuana?
If you're living with Fibromyalgia, you may qualify for a medical marijuana card. Our licensed physicians can evaluate you from home via telehealth.
Related Research & Resources
Related Research
- Medical Cannabis for Fibromyalgia: What 367 Patients Experienced
- Cannabis for Chronic Pain: A Critical Look at 104 Studies
- THC vs CBD for Fibromyalgia: Comparing Cannabis Varieties
- Clinical Practice Guidelines: Cannabis for Chronic Pain & Co-Occurring Conditions (2024)
- Cannabinoids for Arthritis and Rheumatic Pain: Insufficient Evidence
Condition Research
Get Your Card
This condition qualifies for medical marijuana in:
Source
Chaves C, Bittencourt PCT, Pelegrini A "Ingestion of a THC-Rich Cannabis Oil in People with Fibromyalgia: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial" Pain Medicine. 2020. DOI: 10.1093/pm/pnaa303
Important Information
Study Age: This study was published 6 years ago. Newer research may have updated or refined these findings.
Not Medical Advice: This research summary is for educational purposes only. It should not be used to diagnose, treat, cure, or prevent any disease or medical condition. Always consult a qualified healthcare provider before starting or changing any treatment.
Individual Variation: Research findings represent group averages. Your individual response to cannabis may differ based on genetics, other medications, underlying conditions, and many other factors.
Last reviewed: January 24, 2026
Important Notices
Research Summary Disclaimer
This content represents our interpretation of published scientific research for educational purposes. It should not be used to make treatment decisions without consulting a qualified healthcare provider. Individual results may vary from study findings.
FDA Notice
These statements have not been evaluated by the FDA. Cannabis is not intended to diagnose, treat, cure, or prevent any disease. The FDA has not approved cannabis for any medical condition except specific prescription medications.
Copyright & Fair Use
Research summaries are provided under fair use (17 U.S.C. § 107) for educational purposes. We provide brief summaries with attribution, not full reproductions. All studies remain the intellectual property of their respective authors and publishers.
Data Sources
Study information sourced from PubMed®, U.S. National Library of Medicine. Inclusion does not imply endorsement by NLM, NIH, or the federal government.
For complete information, see our Terms of Use and Research Content Policy.
FAQs: Cannabis for Fibromyalgia
Does THC help fibromyalgia?
Yes, according to this trial. Women taking THC-rich cannabis oil for 8 weeks showed significant improvements in pain, fatigue, ability to work, and overall well-being compared to placebo.
What type of cannabis is best for fibromyalgia?
THC-dominant in this study. This study used a THC-dominant oil (24.44 mg/mL THC with minimal CBD). Other studies have used balanced or CBD-dominant products. The optimal formulation likely varies by individual.
What dose of cannabis for fibromyalgia?
Start low, go slow. This trial started very low (~1.22 mg THC per day) and increased gradually based on symptoms. This approach helped minimize side effects while finding an effective dose.