According to Urban Waxx, a Brazilian wax lasts approximately three to four weeks, depending on how fast an individual's hair grows. Women with fast-growing hair may only be able to go two weeks between waxes.
The amount of time it takes for a Brazilian wax to grow out depends primarily on the individual and the rate at which her hair grows. However, someone who repeatedly waxes can go longer and longer between sessions due to the fact that the hair grows back finer and thinner after each wax. This is due to the damage that occurs to the hair follicle and its hair-growing structures during waxing.