Remote Electrical Stimulation as a Long-term Intervention for Endometriosis Flare Ups

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:

1. Laparoscopic surgery with biopsy-proven endometriosis, OR

2. Clear evidence of ovarian endometrioma or deep infiltrating endometriosis onultrasound/MRI

• Mean NMPP NRS (non-menstrual pelvic pain) ≥ 2.5 OR ≥1.25 and ≥5 on at least 4 days (self-report)

• DYS NRS (dysmenorrhea-related pelvic pain) ≥4 on ≥2 days (self-report)

• Access to a smartphone with an internet data plan, phone must be iOS 13.4+, orAndroid 12+.

• No hormonal contraception or at least 6 months of consistent adherence to anyhormonal contraception (e.g., IUD, pill, injection)

• Regular menstrual cycles (24-35 days) for the past six months

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, strokeor 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 anyother neurological condition that, in the opinion of the principal investigator, mayincrease 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 otherbehaviors indicative of intent to harm oneself), as determined by participantself-report

• Treatment plan must be stabilized (4 week analgesic/ 6 month+ hormonalcontraception, and crucially no new medication changes)

• Planning to commence any new treatment during intervention period

• Lack of capacity to consent

• No menstruation