Contrary to popular belief, gray hair might not always be permanent. Scientific discoveries suggest stress, nutritional deficiencies, and hormonal imbalances can trigger graying, with potential for reversal if addressed early. However, age-related decline and certain genetic or autoimmune disorders lead to irreversible graying. However, premature graying could signal underlying health issues.source https://timesofindia.indiatimes.com/life-style/health-fitness/health-news/gray-hair-reversal-how-much-of-natural-hair-color-can-actually-be-restored/articleshow/124554837.cms