The dose- and time-dependent analgesic activity of A) BVD02, B) BVD03, C) AN81 and D) SBCHM01 after i.v. injection at two to four different doses and in comparison with morphine (4 mg/kg, i.p.) Each compound was tested using C57Bl6 male mice and hot water tail-flick test was used. Data are represented as the % of maximal possible effect (%MPE) ± SEM of 6-10 mice. Statistics conducted using a two-way analysis of variance (ANOVA) followed by Bonferroni's test showed significant differences (*p < 0.05; **p < 0.01; ***p < 0.001) between the examined peptides and morphine. Differences are defined as: * for BVD02 (1 mg/kg) and # for BVD02 (0.5 mg/kg); * for BVD03 (4 mg/kg); # BVD03 (1 mg/kg); $ BVD03 (0.5 mg/kg) and * for AN81 (0.1 mg/kg).