Disclosed in a hair care composition comprising: (i) a hair diameter increasing agent comprising a xanthine compound, a vitamin B3 compound, and a panthenol compound; and (ii) an carrier comprising water and monohydric alcohols having 1 to 6 carbons; wherein the monohydric alcohol is present in the composition at a level by weight of from about 10% to about 90%, preferably from about 30% to 90%, and wherein the composition may further comprises a substantially soluble silicone conditioning agent and/or a thickener. The hair care compositions of the present invention provide improved hair diameter increase benefit. The hair care compositions of the present invention also provide improved feel during usage and/or after usage, while not-compromising the penetration of the hair diameter increasing agent.