The present invention relates to a nanoemulsion comprising at least one aqueous component and a carrier, wherein the carrier comprises at least one lipophilic component, at least one surfactant and at least one alcohol. The present invention further relates to a composition comprising said nanoemulsion and an active agent. In particular, the composition is present as a gel and the active agent is 5-aminolevulinic acid, a derivative, precursor and/or metabolite thereof. The invention further relates to the preparation of said nanoemulsion and/or composition and to their use for the treatment of dermatological diseases, virus-associated diseases as well as diseases associated with cell proliferation, in particular, tumor diseases and/or psoriasis. The present invention is further directed to the use of said nanoemulsion in cosmetics.