A doctor warns that topical hair-loss treatments like minoxidil, often used without medical supervision, may pose risks beyond the scalp. Originally developed as a blood pressure medication, minoxidil can enter systemic circulation if overused or applied to broken skin. Potential side effects include palpitations, dizziness, fluid retention, and blood pressure fluctuations, particularly in individuals with pre-existing heart conditions. Emerging concerns also point to eye-related symptoms such as puffiness and irritation.