New co-crystals of agomelatine, a process for their preparation and pharmaceutical compositions containing them Abstract The invention relates to new co-crystal of agomelatine composed of: - agomelatine, or N-[2-(7-methoxy-1 -naphthyl)ethyl]acetamide of formula (I) NHCOMe MeO and - an organic acid. The invention also relates to medicaments and methods of medical treatment.Nuevo co-cristal de agomelatina constituido: - por agomelatina o N-[2-(7-metoxi-1-naftil)etil]acetamida de fórmula (I) (ver fórmula (I)) y - por un ácido orgánico.