research Observational Study of Hair Fall in Rheumatoid Arthritis Patients Treated with Low Dose Methotrexate Compared to Healthy Controls June 2019 in “Poster presentations” Low dose methotrexate does not increase hair fall and may reduce it.
research Assessment and Treatment Outcomes of Persistent Radiation-Induced Alopecia in Cancer Patients 24 citations, August 2020 in “JAMA dermatology” Persistent radiation-induced hair loss is dose-dependent, and treatments like topical minoxidil can be effective.