Background and purpose: This study aimed at evaluating the effects of different doses of Licorice extract on in vitro maturation (IVM) and in vitro fertilization (IVF).

Materials and methods: In this study 32 female adult mice were randomly assigned into four groups. Group I was the control, group II were estradiol valerate-induced PCOS mice (0.2cc), and groups III and IV were induced PCOS that received Licorice extract at 100mg/kg/day and 150 mg/kg/day dosage, respectively for 3 weeks. Afterwards, blood sample were taken and the testosterone and esteradiol levels were measured. GV oocytes were isolated from ovaries and cultured in TEM₁₉₉. The oocytes (MII) were inseminated with sperm. Then, the fertilization and blastocyst stage development were investigated under inverted microscope.

Results: The serum testosterone and estradiol levels significantly decreased in treatment groups compared with PCOS mice (P&le0.05). Also, the number of oocytes, fertilization, number of two-cell and blastocysts significantly increased in treatment groups compared to the PCOS group (P&le0.05).

Conclusion: The results showed that licorice is effective on sex hormones in induced PCOS mice and also it could improve IVM and IVF in induced PCOS mice.