Severe hair thinning can be caused by genetics, stress, hormones, or nutritional deficiencies. For pattern hair loss, the most common FDA-approved medical treatments are topical Minoxidil (to stimulate hair follicles) and oral Finasteride (to block the hormone causing hair thinning). Nutritional supplements like biotin, iron, or zinc can also help if a deficiency exists. Because the most effective medicine depends entirely on the underlying cause of your hair loss, I strongly recommend consulting a dermatologist. They can evaluate your scalp, run necessary blood tests, and prescribe a safe, personalised treatment plan.