Hi! Thanks for your query. Olaplex maximises the strength of hair by reconnecting broken disulphide sulphur bonds in the hair, which gives hair a thicker look and feels healthier and stronger. The hair bonds break when hair is coloured and subject to regular heat and chemical treatments. It allows you to rebuild the strength, structure and integrity of hair and it is compatible with all hair types. For best results, it’s important to use Olaplex during a colour treatment, rather than after it.