The constant increase of life expectancy is associated with major ageing of developed populations. This indicates that the new century will have one of most epidemic progressions of cardiovascular, cancer and inflammatory diseases. The high challenge for medical research is to compress such morbidity. In these conditions, invertebrates have demonstrated to be truly useful models in drug discovery for such ageing diseases. The last decade, drug discovery in leeches has opened the gate of new molecules to treat emphysema, coagulation, inflammation, dermitis and cancer. Also other invertebrates such as insects, which evolved from the annelids, harvest potential interesting molecules, such as serine protease inhibitors that can be exploited by the medical industry.