A process for reducing curl and/or frizziness of hair comprising: (a) providing a composition for reducing curl and/or frizziness of hair, said composition comprising, in a cosmetically acceptable carrier: (i) at least one non-hydroxide base; (ii) at least one protein denaturant different from (a)(i); (iii) at least one alkoxysilane comprising at least one solubilizing functional group; and (iv) optionally, at least one fatty substance; (b) contacting the hair with the composition in (a) to form treated hair; (c) optionally, rinsing the composition in (a) from the treated hair; (d) optionally, contacting the treated hair with a conditioning agent; (e) smoothing the treated hair using a combination of heat and means for physically smoothing hair to form smoothed hair; (f) optionally, shampooing the smoothed hair; and (g) rinsing the smoothed hair.