my friends and i used to iron our hair with an iron (stone) to straighten it, we did the best at that time, was a bit dry though. but technologies gone further to produce the revolutionary ghd. you do not have to use serum, it just gives you that beautiful straight and silky hair. your hair remains shiny, it does not burn. it is a bit pricey, but, you do not have to go to the salon for that great looking hair. i am still amazed at the results. it makes you feel, and look beautiful, round the clock. i really do not know what i would do without my ghd. i just love it!!!!