If you want to show that your product, or styling device, prevents or repairs hair damage, then you may consider measuring the levels of hair protein damage inside the hair using differential scanning calorimetry (DSC).

DSC involves heating a sample over a given temperature range.  As you heat the sample, you reach a temperature where the hair keratins inside the hair start to change in structure and denature.  This change is similar to the changes you get when you heat egg yolk.  The proteins in the hair, and in egg yolk, restructure and change irreversibly.  The temperature at which hair keratins denature changes with hair damage, so DSC can be used as a good measure of protein damage and repair.  TRI have used DSC to investigate hair damage from many different damaging treatments, such as bleaching, UV-irradiation and gaseous pollution.  DSC measurements are sensitive to many experimental factors.  TRI is able to provide expert advice on designing the best protocols and on interpretation of the data.