Hi1 I'm 21 years old and I am now working at a hotel as a receptionist, I am tan eversinced but when I heard about metathione, me and my other officemate tried it, for my hope that this is the answer to my skin lightening, but I am also drinking coffee everyday, is it OK? Or will it be a problem with regards to the result of metathione to me?

No. Methathione and coffee are both anti oxidants that helps liver to clean your body. Metathione's skin little lightening effect is just an effect because liver is cleansed.