The goal of this interventional study is to learn whether noninvasive brain stimulation (NIBS) will have an effect on pain perception in people with fibromyalgia. The main questions it aims to answer are:

Do repeated sessions of NIBS lead to a reduction in perceived pain? Do repeated sessions of NIBS lead to an improvement in quality of life?

Researchers will compare different brain targets to see if effects are different between them.

Participants will receive repeated daily sessions of NIBS over 4 weeks with application of pressure pain algometry, and complete various questionnaires.

Participants will randomly receive primary motor cortex (M1) or occipital lobe NIBS over 2 weeks, and after a wash-out period will receive NIBS of the other target over 2 weeks. Each session will also evaluate pressure pain algometry, various questionnaires to assess changes in fibromyalgia symptoms and quality of life (up to 5 hours per session)

NIBS administration will consist of 1000 electrical pulses of <1 ms duration each.

Inclusion Criteria:

• Formal diagnosis of fibromyalgia made by a practicing physician
• Pain resistant to common analgesics and medications for chronic pain
• Existing pain for more than 3 months with an average of at least 4 on a 0 to 10 Numerical Rating Scale (NRS)
• Females of child bearing potential must be at least one of the following totally abstinent from heterosexual intercourse since the last menses before start of study, or agree to concurrent use of at least two methods of birth control throughout study participation.

Exclusion Criteria:

• If the subject is non-ambulatory.
• If the subject is female of child-bearing potential, subject must not be pregnant.
• Subject must not have a history of brain surgery or uncontrolled neurological conditions, such as seizure, fainting spells, transient ischemic attack.
• Subject must not have lifetime history of severe, uncontrolled mood disorders (anxiety, depression, bipolar), psychotic disorders, other neural disorders, or heart disease.
• Subject must not have any implanted electronic or metallic devices.
• Subject must not have heart diseases, including known arrhythmia, or severe liver or severe gastrointestinal disease or chronic severe infectious disease (e.g. HIV/AIDS).

IPD may be shared upon reasonable request to the study contacts.

Data will become available after publication per journal and funding entity protocols.

Data will be made available by reasonable request and/or per journal and funding entity protocols.