Shaping keratin fibres using an active agent comprising at least two functional groups selected from: -c(oh)- and -c(=o)oh

A method for shaping keratin fibres comprising:

• (a) providing a solid composition, wherein the solid composition comprises:
• an active agent, the active agent comprises at least two functional groups selected from:
• —C(OH)— and —C(═O)OH;
• and wherein if the active agent has three or more —C(OH)— groups, then the active agent has 4 or more carbon atoms;
• and wherein no 1 carbon atom is functionalized with more than one functional group;
• wherein the active agent has a molecular weight of about 500 g/mol or less;
• a photocatalyst being a hydroxy-substituted aromatic compound;
• and then mixing the solid composition with a cosmetically acceptable carrier to form a crosslinking composition;
• (b) applying the composition to keratin fibres, mechanically shaping the keratin fibres with an appliance or implement, and exposing the composition to electromagnetic radiation having a wavelength of from about 300 nm to about 750 nm.

A crosslinking composition for shaping keratin fibres comprising:

• an active agent, the active agent comprises at least two functional groups selected from:
• —C(OH)— and —C(═O)OH;
• and wherein if the active agent has three or more —C(OH)— groups, then the active agent has 4 or more carbon atoms;
• and wherein no 1 carbon atom is functionalized with more than one functional group;
• and wherein the active agent has a molecular weight of about 500 g/mol or less;
• a photocatalyst being an aromatic hydroxy compound, wherein the aromatic hydroxy compound is multicyclic.