Abstract: The present invention relates to a composition comprising —a gelled aqueous phase, —at least 1% by weight of active material of magnesium salt(s) having a poured bulk density of greater than 450 g/L, relative to the total weight of the composition, and —at least one glycol derivative, characterized in that the glycol derivative is chosen from propylene glycol, butylene glycol and mixtures thereof. The invention also relates to a cosmetic process for treating body odour associated with human perspiration, notably underarm odour, and optionally human perspiration, which consists in applying to the surface of the skin, in particular using a roll-on, an effective amount of said cosmetic composition.