Yes, some regrowth is possible, but it depends on whether the hair follicles are still active after three to four years. Ayurvedic herbs like Bhringraj, Brahmi, and Amla, alongside natural options like rosemary oil, can improve scalp circulation and strengthen existing hair. However, for significant regrowth on the vertex and crown, natural remedies alone have limited scientific evidence. For more robust results, medically proven generic treatments like topical minoxidil or finasteride are highly effective. I recommend consulting a dermatologist to assess your hair follicles and design a tailored plan that can safely combine natural care with medical treatments.