A medical or cosmetic formulation such as pastes, gels, lotions, serums, creams, peels and sprays comprising 4-n-butylresorcinol in a concentration greater than substantially 18% preferably between substantially 20% and substantially 60% diluted with a hydrophilic agent, or any diluent known in the art, can be used for treating various skin conditions, e.g. complexion, hyperpigmentation, melasma, pore size, skin density, hydration, superficial scars, post-operative scars, hypertrophic and atrophic scars, post-inflammatory hyperpigmentation, solar lentigines, acne vulgaris and as an anti-aging treatment. The formulae include peels and skincare using various delivery systems, such as liposomal delivery systems and all agents to aide penetration of the epidermis, known in the art. Compositions may include preservatives, such as levulinic acid. Formulation embodiments of the invention can have any one or more of the following features: • Said formulation is between substantially 18% and substantially 60% • Sa
