Could a headband ease endometriosis pain? new study tests At-Home brain zaps

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria * Female, 22-45 years old * Assigned female at birth * Fluent in English * Capacity to consent * Confirmed diagnosis of endometriosis by a qualified physician, via: * Laparoscopic surgery with biopsy-proven endometriosis, OR * Clear evidence of ovarian endometrioma or deep infiltrating endometriosis on ultrasound/MRI * Pain levels: For menstruating participants, all of the following need to be met: * Regular menstrual cycles (21-35 days) * Mean DYS NRS ≥4 during menstrual bleeding days (over the last 28 days, self-assessed) * AND Mean NMPP NRS ≥4 during non-menstrual days (over the last 28 days, self-assessed) For non-menstruating patients, all required: * Irregular/absent cycles OR post-hysterectomy OR surgically menopausal * Mean pelvic pain NRS ≥4 (over the last 28 days, self-assessed) * Pain present on ≥50% of days * Access to a smartphone with an internet data plan, phone must be iOS 13.4+, or Android 12+. * No hormonal contraception or at least 6 months of consistent adherence to any hormonal contraception (e.g., IUD, pill, injection). * Capacity to follow instructions and operate the study device. Exclusion Criteria * Pregnancy/breastfeeding or planning to become pregnant in next 6 months * History of epileptic neurological conditions in the immediate family * Severe/untreated neurological disease (e.g., epilepsy or seizure disorders, stroke or transient ischemic attack \[TIA\], subarachnoid hemorrhage, traumatic brain injury \[TBI\] with persistent neurological deficits, brain tumors \[malignant or benign\], multiple sclerosis, Parkinson's disease, Alzheimer's disease or other dementias, Huntington's disease, cerebral aneurysms or arteriovenous malformations \[AVMs\], active central nervous system infections \[e.g., meningitis, encephalitis\], hydrocephalus, other neurodegenerative diseases not otherwise specified, or any other neurological condition that, in the opinion of the principal investigator, may increase risk or interfere with study participation or outcomes) * Metal implants/electronic devices in brain, head, or neck area * Participating in any other clinical trial * History of stroke, brain surgery, tumors, head trauma * Active skin lesions, open wounds, cuts, or infections on the scalp * Active scalp conditions (dermatitis, eczema, psoriasis) * Significant scarring/burns/other skin damage on scalp * Schizophrenia or bipolar disorder * History of suicidal behavior or clinically significant self-injurious behavior (e.g., one or more suicide attempts, non-suicidal self-injury \[NSSI\], or other behaviors indicative of intent to harm oneself), as determined by participant self-report. * Treatment plan must be stabilized (≥6 weeks analgesic/ ≥6 months hormonal contraception, and crucially no new medication changes before randomization) * Planning to commence any new treatment during intervention period * Lack of capacity to consent * Participation in a neurotechnology or drug trial in the last 6 months. * Recent surgical intervention for endometriosis within 6 months of enrollment or planned surgical intervention for endometriosis during the study period.