Disclosed is a method for increasing hair diameter, comprising the steps of: topically applying a first composition comprising to a region where hair diameter increase is desired; and topically applying a second composition to a region where an additional benefit is desired; wherein the first composition comprises a hair diameter increasing agent comprising a xanthine compound, a vitamin B3 compound, and a panthenol compound; and wherein the second composition comprises an additional benefit agent, such additional benefit being selected from the group consisting of hair volume-up, hair conditioning, hair strengthening, scalp sensation, hair color, scent, and mixtures thereof. The kits and methods of the present invention increase hair diameter, and also provide: motivation to consumers to use such compositions for a longer period of time so that consumers can obtain hair diameter increase benefit; at least one additional benefit, while not-compromising the penetration of the hair diameter increasing agent; and/or optimized benefits from both hair diameter increasing agents and additional benefit agents.