Hair conditioning composition comprising: from about 2.0% to about 9.0% reducing agent, wherein the reducing agent is selected from the group consisting of: ammonium thioglycolate; ammonium thiolactate; and mixtures thereof; from about 0.5% to about 1.5% alkalising agent; from about 2.0% to about 10% conditioning agent selected from the group consisting of: silicone compounds; cationic surfactants; and mixtures thereof; a buffering agent. The composition has a pH of from about pH 7.5 to about pH 9.5 and a viscosity of from about 500 mPa·s to about 5500 mPa·s measured at 25°C. The composition is substantially free of an additional reducing agent capable of reducing disulfide bonds in keratin fibres. Also associated methods, processes, kits and uses.