Disclosed is a lipophilic extract of brown algae gametophytes obtained by the method including the following consecutive steps: —a Step A) for preparing a hydro-alcoholic suspension of gametophyte cells by mixing an aqueous suspension of brown algae gametophyte cells with at least one aliphatic alcohol including 1 to 4 carbon atoms; —a Step B) for mixing the hydro-alcoholic suspension of algae gametophyte cells, obtained in Step A), with at least one triglyceride from fatty acids that include 8 to 22 carbon atoms; —a Step C) for adding water to the multiphase mixture obtained in Step B); and —a Step D) for isolating the lipophilic extract of brown algae gametophytes from the mixture obtained in Step C). Also disclosed are the cosmetic and pharmaceutical use of the extract.