14 years girl. gradual hair thinning for several years. several experts checked all. no alopecia areata. uses minoxil 5. helps but not stopping.ideas?

Multiple causes: When someone has diffuse gradual thinning, I like to order some tests to look at their thyroid function, iron level, vitamin D level, hormone levels, and their risk for autoimmune disease. If there is no answer, then sometimes a biopsy is helpful. In addition to minoxidil, supplements by Viviscal as well as topical caffeine products can be helpful depending on the pattern of hair loss.