Over time, this weakens the hair shaft, making it brittle, dry, and prone to breakage. Frequent bleaching and colouring also degrade the hair’s protein structure, leading to split ends and ...

red‒green axis, and yellow‒blue axis — but we have not had a technique that quantifies what is happening with the dye in the hair fibre. Using high-performance liquid chromatography on ...

“Given the recent North American data as well as the importance of PTDS as an alternative hair dye option for some patients with PPD contact allergy, we advocate that PTDS be considered for ...