Hair Straightening, Shampoo & Conditioner
A: Well, this is always a tough question. It really depends on the type of straightening you've had done, whether it's the newer Japanese Thermal Restructuring, or a more traditional Thio-based straightening process.
The Japanese Thermal Restructuring process and its accompanying products are designed as a whole to help maintain the needs of the hair. However, I don't see why you can't use other products, as long as they don't contain ingredients that would interfere with the chemicals used to straighten the hair.
The big concern you should bear in mind is that in many salons, particularly when it comes to the more expensive process of Japanese Straightening, not using the products they sell for aftercare can result in losing any claim to warranty on the straightening service. This means that if you choose to use your own products as opposed to what they suggest, the salon may refuse any liability if you have problems after the service.
©Hairfinder.com
See also:
What is Japanese Thermal Restructuring?
Does expensive shampoo make a difference?
Should I be using the same products the hair salon uses?
Once the hair is straightened, how do you take care of it?