The present invention discloses novel complex molecules useful as anti-allergic agents. These complex molecules include in particular, peptidic or peptidomimetic molecules, having a first segment which is competent for cell penetration and a second segment which is able to reduce or abolish mast cell degranulation, and in particular to reduce or abolish allergy mediators such as histamine secretion from mast cells. Specific examples of peptides with the desired activity are disclosed.