The answer is YES you can. Some of the deep curly or wavy patterns may be challenging to straighten because the curl pattern is so deep and it will take a long time. It is very important that you use a quality heat protectant on your hair. Your hair is 100% pure human hair so it can become heat damaged just as your own hair would. Also, with curly/wavy hair you risk the chance that your curl pattern will not return after applying excessive heat to your hair repeatedly just as your natural hair would respond. If you continually apply heat to your hair, you will begin to train your hair to be straight. Our suggestion is; if you want curly hair, then wear your Virgin hair curly. If you prefer to wear your hair straight or wavy, then the wavy textures will be best for you since they offer the most versatility.