Background <p>The gonadotropin-releasing hormone plays a key role in reproduction. Lecirelin is a nonapeptide analogue of GnRH that is used to stimulate ovulation in cows, horses, and rabbits. It is used to treat ovarian cysts.</p> Purpose <p>This study aimed to design and synthesise new derivatives of Lecirelin, and the evaluation of super-ovulation, mating, and embryo recovery of that in the laboratory conditions on mice.</p> Method <p>The synthesis of Lecirelin was carried out in the solid phase. Lecirelin was synthesized on 2-CTC resin and C-terminal of the peptide chain was changed. The identification of purified peptide was confirmed by Mass spectrometry. The experimental groups for the animal study consisted of the control group (injection of LH), treatment 1 (injection of Lecirelin), treatments 2, 3, and 4 (injection of newly designed derivatives of Lecirelin), and super-ovulation procedures. Mating was conducted naturally.</p> Results <p>In the hydrazide derivative had 7% more healthy-formed embryos than the original Lecirelin sample and about 20% more than its amide derivative, indicating that the number of healthy embryos in the hydrazide sample was significantly higher than in the main sample of Lecirelin and its amide derivative.</p> Conclusion <p>The results showed high effectiveness of derivative designed with the hydrazide end of Lecirelin on the ovulation rate and the health of embryos.</p>