The influence of gamma-L-glutamylhistamine analogues on the hexenal-induced sleeping, glucocorticoid hormone content in blood plasma and severity of experimental anaphylactic reaction was studied. It was observed that gamma-L-glutamylhistamine analogues caused decrease in the sleeping time and severity of experimental anaphylactic reaction, the elevation of glucocorticoids content in blood plasma. The present results indicate that substances have the wide spectrum of biological activity which depends on the length of the N-acyl radical.