Cerise Naturals Reverse Grey Hair Serum starts showing results in 75 days depending on the physical health of the individual using it. Made with natural ingredients Arcolys, Black Tea and Aloe Vera this Serum makes hair darker denser with regular usage of 150 days. https://cerisenaturals.com/blogs/organic-skin-care/which-hair-serum-is-the-best-to-reverse-grey-hair