Using hashish oil to soften the hair
Question

                What is the ruling on oil that is derived from hashish, to soften the hair etc.?
Praise be to Allah.If the oil is derived from the hashish which 
          intoxicates and which is not allowed to be sold because it contains 
           forbidden intoxicating substances, it is not permissible to use 
          it. Allaah does not put the cure of the ummah of Muhammad in something 
          that He has forbidden for them. If the hashish in question is the hashish 
          which causes intoxication and is classed as a drug, then it is not permissible 
          to use it and treat disease with it. These drugs are harmful and are 
          themselves a disease. It was narrated from Umm Salamah that the Prophet 
           (peace and blessings of Allaah 
          be upon him) said: “Allaah does not put the cure for my ummah in something 
          that He has forbidden to them.” And Allaah knows best.