This question has come across while I was doing some research, and the expert has answered this question positively… the expert said that, there is no problem in straightening our hair as long as we use the flat iron in a proper adjusted heat to protect our hair from being damaged and we can test the heat of the flat iron on a tissue paper; if the paper got discolored, that means the heat of the flat iron needs to be adjusted, but if the color of the paper was fine, it shows that the heat of the flat iron is adjustable and we can definitely apply it to our hair without worries.. Besides, we should not forget to apply weekly deep conditioning treatment plus daily leave-in conditioner to get a smooth straight daily hair…