Shaping keratin fibres using oxoethanoic acid and/or derivatives thereof

A method for shaping keratin fibres comprising:

• (a) providing a solid composition, wherein the solid composition comprises:
• an active agent, wherein the active agent is selected from the group consisting of:
• oxoethanoic acid, 2,2-dihydroxyethanoic acid, 2,2′-oxybis(2-hydroxy)-ethanoic acid, a derivative thereof, and mixtures thereof;
• and 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, wherein the active agent is selected from the group consisting of:
• oxoethanoic acid, 2,2-dihydroxyethanoic acid, 2,2′-oxybis(2-hydroxy)-ethanoic acid, a derivative thereof, and mixtures thereof;
• and wherein the active agent has a molecular weight of about 500 g/mol or less;
• a photocatalyst being a hydroxy-substituted aromatic compound, preferably wherein the hydroxy-substituted aromatic compound is multicyclic.