I've been on it for 3 months. I still have some grey hairs but one surprising benefit I noticed is I normal bowel movements ever since taking this. He Shou WU has so many healing properties besides just changing your hair color. I was someone who suffered from upset stomachs often and have had very little of it since taking this. I am still waiting to see if my hair color changes and will begin my 4 month soon. But the other benefits make it worthwhile too.